HomeMy WebLinkAboutSUS109Fishes of the Lower Churchill River,
Labrador
:yan
~"Ch and Resource Services Directorate
tment of Fisheries and Oceans
ox 5667
1n's, Newfoundland A 1 C 5X1
February 1980
Fisheries & Marine Service
Technical Report No. 922
I+ ~:laes and Environment
Fisheries
and Marine Service
Pkhes et Environnement
Canada
Service des p!khes
et de Ia mer
Fisheries and Marine Service
Technical Reports
These reports contain scientific and technical information that represents an
important contribution to existing knowledge but which for some reason may not
be appropriate for primary scientific (i.e. Journal) publication. Technical Reports
are directed primarily towards a world wide audience and have an international
distribution. No restriction is placed on subject matter and the series reflects the
broad interests and policies of the Fisheries and Marine Service, namely, fisheries
management, technology and development, ocean sciences and aquatic environ-
ments relevant to Canada.
Technical Reports may be cited as full publications. The correct citation
appears above the abstract of each report. Each report will be abstracted in Aquatic
Sciences and Fisheries Abstracts and will be indexed annually in the Service's index
to scientific and technical publications.
Numbers 1-456 in this series were issued as Technical Reports of the Fisheries
Research Board of Canada. Numbers 457-714 were issued as Department of the
Environment, Fisheries and Marine Service, Research and Development Director-
ate Technical Reports. The series name was changed with report number 715.
Details on the availability of Technical Reports in hard copy may be obtained
from the issuing establishment indicated on the front cover.
Service des peches et des sciences de Ia mer
Rapports techniques
Ces rapports contiennent des renseignements scientifiques et techniques qui
constituent une contribution importante aux connaissances actuelles mais qui, pour
une raison ou pour une autre, ne semblent pas appropries pour Ia publication dans
un journal scientifique. II n 'y a aucune restriction quant au sujet, de fait, Ia serie
reflete Ia vaste gamme des interets et des politiques du Service des peches et de Ia
mer,~notaffiQ1ent gestion des peches, techniques et developpement, sciences
oceaniques et environnements aquatiques, au Canada.
Les Rapports techniques peuvent etre consideres comme des publications
complete~e titre exact paraltra au haut du resume de chaque rapport, qui sera
publie dans Ia revue Aquatic Sciences and Fisheries Abstracts et qui figurera dans
!'index annuel des publications scientifiques et techniques du Service.
Les numeros 1-456 de cette serie ont ete pub lies a titre de Rapports techniques
de !'Office des recherches sur les pecheries du Canada. Les numeros 457-700, a titre
de Rapports techniques de Ia Direction generale de Ia recherche et du
developpement, Service des peches et de Ia mer, ministere de I'Environnement. Le
nom de Ia serie a ete modifie a partir du numero 701.
La page couverture porte le nom de l'etablissement auteur ou l'on peut se
procurer les rapports sous couverture cartonnee.
ign by Christine Rusk
Fi~heries and Marine Service
Technical Report 922
February 1980
FISHES OF THE LOWER CHURCHILL RIVER, LABRADOR
by
P. M. Ryan
Research and Resource Services Directorate
Department of Fisheries and Oceans
P.O. Box 5667
St. John's, Newfoundldnd AlC 5Xl
This is the fifty-seventh Technical Report from the
Research and Resource Services Directorate, St. John's.
i i
(c) Minister of Supply and Services Canada 1980
Cat. no. Fs 97-6/922 ISSN 0701-7626
iii
CONTENTS
Abstract/Resume
Page
........................................................ vi
Introduction ............................................................. 1
Materials and Methods .................................................... 4
Study sections ................................................. ~ . . . . 4
Water chemistry ................................... ; ........... '...... 4
Fish capture ........................................................ 4
Catches ............................................................. 5
Growth in 1 ength. . . . . . . • . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Growth in weight relative to length ................................. 5
Sex ratios and maturity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Food studies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Selection by gear ................................................... 6
Mortality rate ...................................................... 6
Potential fish yields in the proposed Reservoirs .............. -...... 6
Habitat description ...................................................... 7
Physical ............................................................ 7
W~ter q~alitY···:··················································· 11
D1 scuss1 on.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Re 1 at i ve abundance of fish. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Total catches ....................................................... 14
Species composition ................................................. 14
Discussion .......................................................... 17
Northern pike..................... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Catches ............................................................. 17
Growth in length .................................... :.. . . . . . . . . . . . . . 19
Growth in we·; ght. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Sex ratios and maturity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Food ....................................... -......................... 20
Selection by gear .................................... " ............... 21
Mortality rate ...................................................... 21
Discussion .......................................................... 24
Lake whitefish ........................................................... 25
Catches ............................................................. 25
Growth in length .................................................... 26
Growth in weight .................................................... 27
Sex ratios and maturity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Food ................................................................ 28
Selection by gear ................................................... 28
Mortality rate ...................................................... 32
Discussion .......................................................... 32
Longnose sucker. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Catches ............................................................. 33
Growth in 1 ength. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Growth in weight. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Sex ratios and maturity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Food ................................................................ 35
Selection by gear ................................................... 36
Mortality rate ...................................................... 38
Discussion .......................................................... 39
iv
White sucker ............................................................. 39
Catches ............................................................. · 39
Growth in length. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Growth in weight .................................................... 41
Sex ratios and maturity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Food ................................................................ 42
Selection by gear ................................................... 43
Merta l i ty rate ...................................................... 45
Discussion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Brook trout .............................................................. 46
Catches ............................................................. 46
Growth in length .................................................... 46
Growth in weight .................................................... 49
Sex ratios and maturity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Food ............................................................ · .... 50
Selection by gear ................................................... 51
Mortality rate ...................................................... 51
Discussion .......................................................... 51
Burbot .... :. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Catches ............................................................. 53
Growth in length. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . 55
Growth in weight ............................ ; .'...... . . . . . . . . . . . . . . . . 55
Sex ratios and maturity .......................... : . . . . . . . . . . . . . . . . . . 56
Food ................................................................ 56
Selection by gear ................................................... 56
Mortality rate ...................................................... 59
Discussion .......................................................... 59
Lake trout ............................................................... 60
Catches ............................................. · ................ 60
Growth in length .................................................... 61
Growth in weight........ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Sex ratios and maturity ........................ ~ . . . . . . . . . . . . . . . . . . . . 62
Food ................................................................ 62
Selection by gear ................................................... 62
Mortality rate ..................•................................... 64
Discussion .......................................................... 64
Ouananiche (landlocked salmon) .......................................... ~ 65
Catches .......................... :. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Growth in length .......... · ................................... ·.".·~:. . . . 65
Growth in weight ............................................... ·~·. . . 67
Sex ratios and maturity ..................................... ·. :'f·~r.~ . . . 67
Food ................................................................ 67
Selection by gear ................................................... 68
Mortality rate ...................................................... 69
Discussion .......................................................... 70
v
Round whitefish .......................................................... 70
Catches ............................................................. 70
Growth in length .................................................... 72
Growth in weight .................................................... 72
Sex ratios and maturity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
Food ................................................................ 73
Selection by gear ................................................... 73
Mortality rate ...................................................... 75
Discussion .......................................................... 76
Lake chub. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Catches ............................................................. 77
Food ...................................... ~ ......................... 78
Discussion .......................................................... 78
Rainbow Sme 1 t........ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Catches ............................................................. 78
Food ...................................... · .......................... 78
Discussion .......................................................... 78
Other species .................................... , . . . . . . . . . . . . . . . . . . . . . . . 79
Fish harvests from the Gull Island and Muskrat Falls Reservoirs .......... 79
Potential fish yields .............. , ................................ 79
Discussion ................................................. ~ ........ 81
Summary .................................................................. 82
Acknowledgments ................. ·. . . . . . . . . . . . . • . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
References ... · ..... · .· .· . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Appendices
I Sample sites ................................................. · ....... 89
II Individual measurements of water quality, Lower Churchjll River ....• 97
III Composition of the gillnet catch .................................... 101
IV Body-scale relationships of fishes from the Lower Churchill River ... 107
V Age:-1 ength data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111 • t ~ •
VI' Sex· 'r'atios of fishes from the Lower Churchill River ................. 123
~ . ~ . '
VII Length at maturity of fishes from the Lower Churchill River ......... 127
VIII Catch statistics of fishes from the Lower Churchill River ........... 135
IX Age and length-frequency distributions of fishes from the Lower
Churchill River ..................................................... 147
vi
ABSTRACT
Ryan, P. M. 1980. Fishes of the Lower Churchill River, Labrador. Fish.
Mar. Serv. Tech. Rep. 922: vii + 189 p.
The fish populations and water quality of five sections of the Lower
Churchill River, Labrador, were surveyed from June to August, 1975-76;
prior to the proposed creation of the Gull Island and Muskrat Falls Reservoirs.
Overall, the fish habitat was characterized by very soft water having a
pH of 6.3, a conductance of 18.9 ~hos/cm, a total hardness of 8 ppm, a .
total alkalinity of 6 ppm, a calcium concentration of 1.4 ppm, a turbidity
of 3.4 JTU, and a chloride concentration of 0.8 rpm. Fish species captured
in gillnets during the survey were, in order· of relative abundance by
weight, northern pike, lake whitefish, longnose suckers, white suckers,
brook trout, burbot, lake trout, ouananiche, round whitefish, lake chub,
and rainbow smelt. In addition, threespine sticklebacks and a species of
sculpin were identified in stomach contents. The relative abundance,
growth rates, sex ratios, and stomach contents of species captured varied
from section to section throughout the river. Detailed information on the
relative abt.:ndance and biology of th_e individual species throughout the
river are included in this report. Long-term potential fish yields were
estimated to be 1.01 kg/ha/yr or 20,099 kg/yr in the proposed Gull Island
Reservoir and 1.26 kg/ha/yr or 12,474 kg/yr in the,1J;ropg>s~d Muskrat Falls
Reservoir. In each reservoir, just over half of the potential yield estimated
was comprised of longnose and white suckers. Of greatest potential impact of
impoundment upon fish populations in the proposed reservoirs are fluctuating
water levels and increased sedimentation.
Key words: abundance, food, growth, maturity, mortality, potential yield,
reservoirs, sex ratios
.. ..
RESUME
Ryan, P. ~1. 1980. Fishes of the Lower Churchill River, Labrador. Fish.
Mar. Serv. Tech. Rep. 922: vii + 189 p.
Avant la cr§ation des r§servoires de Gull Island et Muskrat Falls, la
population des poissons et la qualite de l'eau furent examinees dans cinq
endroits sur la riviere de Lower Churchill, durant les mois de juin jusqu'au
mois d'aout 1975-76. L'habitat marine en majorite etait caracterise par
l'eau extremement douce ayant un pH de 6.3, une conductance de 18.9 JlJ11hos/cm
une durete totale de 8 ppm, une alkalinite totale de 6 ppm, une concentration
du calcium de 1.4 ppm, une turbidite de 3.4 JTU, et une concentration du
chlorure de 0.8 ppm. Les especes de poissons pechees par fillets maillants
durant l'etude, enumerees par l'abondance du paid cueilli furent le grand
brochet, la grande corregone, le meunier rouge, le meunier nair, la truite,
vii -
la lotte, le touladi, l'ouananiche, le menomini rond, le mene de lac et
l'eperlan arc-en-ciel. L'epinoche a trois epines et une espece de chabot
furent identifies dans le contenu d'estomac. L'abondance relative, le
taux de croissance, la proportion des sexes et le contenu des estomacs
des especes capturees varient de section en section le long de la riviere.
L'information detail lee sur 1 'abondance relative et la biologie des
especes individuelles sont inclus dans ce rapport. Le potentielle du
rendement au long terme fut ~stime a 1.01 kg/ha/an ou 20,099 kg/an pour
le reservoir propose de Gull Island et 1.26 kg/ha/an ou 12,474 kg/an pour
le reservoir propose de Muskrat Falls. POur chaque reservoir, le meunier
rouge et le meunier noir comprenaient plus que la moitie de 1 'estime du
rendement. L'oscillation ~u niveau de 1 'eau et 1 'augmentation du sediment
dans les reservoirs prtrpo~s sont les potentiels d'impact plus prononces
sur la population des poissons internes.
( j \
INTRODUCTION
This report is an assessment of the fishery resource uf the Lower Churchill
River, Labrador.
The Lower Churchill River (Fig. 1) has been proposed as the location of
two reservoirs to be used for the development of hydroelectric power. The Gull
Island hydroelectric project entails the erection of a dam across the Lower
Churchill River near Gull Island approximately 110 km upstream from Happy
Valley-Goose Bay. The Muskrat Falls project will deriv.e power from a dam at
MusJ<rat Fa 11 s, 30 km upstream from Happy Van ey-Goose Bay. The two reservoirs
(Table 1) will depend largely on available river discharge for power generation
in a run-of-the.:.river scheme. Detailed descriptions of the two proposed
reservoirs and their operating modes have been documented by Thurlow and Associates
(1974), Gull Island Power Company Limited (1977), Acres Consulting Services Limited
(1978), and Lower Churchill Development Corporation Limited (1979).
t2'
1001010015>
I e e l:seel t+e+t
IILOIIETID
~··
Fig. 1. Location of the Lower
Churchill River, Labrador and five
river sections considered in the
present study.
2
Table 1. Physical features of the proposed Gull Island and Muskrat Falls Reservoirs.
Reservoir
Feature Gull Island Muskrat Falls
Volume (total storage m3 x 109)*
Mean water flow (m 3 /s)*
Surface area (km 2 )t
Maximum drawdown (m)t
Maximum depth (m)t
Mean reservoir depth (m):j:
4. 1
1770
199
6.1
88
20.6
* Acres Consulting Services Limited: 1978.
t Lower Churchill Developm~nt Corpg
1
ration Limited, 1979.
:j: Volume/area
1.3
1833
99
4.0
36
13.1
Detailed information on aquatic vegetation, physical features, and habitat
classification of the Lower Churchill River have yet to be documented. This
information is to be documented by the Lower Churchill Development Corporation
as part of the project environmental impact study. s~'
-i It,is accepted among hydrobiolggists that it is generally diffj~yJt to
predict the condition of fishery resources in a proposed,reser:YQ-ir;-particularly
one obtai ned by damming a river. This difficulty is pri~.r;'ily due to the
complexity of ecological interactions that affect fish anc:l'the fact that few
impact assessments have been made before and after the creation of a reservoir.
In Canada, there is as yet no measure of the accuracy of a pre-impoundment
prediction of a fishery resource (Harvey 1976). However, certain similarities
have been observed among reservoirs created from rive~s. ~~
As reviewed by Geen (1974), the damming of aE f:~ee-flowing river generally
results in:
-lost river fauna ·~s~~
-blocked access to spawning areas 1 nor:cJ
-initial increases in reservoir productivijlj:i'r!Allcwed
by an eventual decline
-low littoral productivity as a result of drawaown
-decreased turbidity through settling of sediments in
the reservoir
-initial increases in total dissolved solids from the
leeching of flooded terrain and breakdown of terrestrial
plant material
-a little affected plankton production and water
chemistry in the long term
-reduced growth rates of littoral feeding fishes
-and an altered abundance of fish and their food organisms
3
Obviously, it may take many years before a period of biological stability
can be attained by a new impoundment. In the Kerelian U.S.S.R., an area similar
to western Labrador, stabilization of reservoir ecology begins to take place
about 20 years after flooding (Baranov 1961). Thus, the accuracy of pre-impoundment
predictions cannot be fully assessed within a short time frame.
It is hoped that the data presented here will assist in the utilization of
the available fish resource in the Gull Island and Muskrat Falls Reservoirs and
assist in the prediction of effects of other reservoirs. With these objectives
in mind, emphasis was placed on the following areas of study:
1. The relative abundance of fish species in the Lower Churchill
River. The estimates of relative abundance and the presence or
absence of the various species (Table 2) 'Were based on catches obtained
during survey work in 1975 and 1976 and on distribution maps of fishes
presented by Scott and Crossman (1973)..
Table 2. List of fishes occurring in the Lower Churchill River,
Labrador. Based on surveys in 1975 and 1976and on distribution
maps presented by Scott and Crossman (1973).
Northern pike
Lake whitefish
Longnose sucker
White sucker
Brook trout (sea-run and
r:esident) .,
Burbot ', f
ta1<e trot{t ~;n
Atlantfc sa1fubin (sea-run and
resident ouananiche)
.Round whitefish
Rainbow smelt (sea~run)
Lake chub · ·
Arctic char (sea~run)
Threespine stickleback
Ninespine sti'ci<:Teback B
Mottled sculpin
Slimy sculpin
American eel (sea-run)
Longnose dace
iAtlantic sturgeon (sea-run)
H.f
)
Esox luaius
CoPegonus alupeaformis
Catostomus aatostomus
Catostomus aorronepsoni
Salvelinus fontinalis
Lota Zota
Salvelinus namayaush
Salmo salaP
Pro's opium ay Und!'aaeton
Osmerus moPdax
Coue,sius plumbeus
Salvelinus alpinus
GastePosteus aauleatus
Pungi#us pungi tius '
Cottus baiPdi
Cottus cognatus
Anguilla POBtY'ata
Rhiniahthys aataPaatae
AaipenseP oxyPhynahus
2. The biology of the fish species in the Lower Churchill River. This
information was obtained from analyses of the individuals captured
during the surveys and from literature sources. The potential
impact of reservoir construction on each species is considered.
4
3. The potential yield of fishes in the Gull Island and Muskrat Falls
Reservoirs. Estimates of maximum sustainable yields were based on
catches obtained during the surveys and predictive models previously
used.
MATERIALS AND METHODS
STUDY SECTIONS
The Loweti' Churchill' River., from its mouth to the tailrace at Churchill
Falls, was divided into five study sections on the basis of physical characteristics
and the locations of the proposed dams. Within each section, stations were
selected at approximately 8 km intervals (Fig. 1). The five sections chosen and
the survey dates are:
I -River Mouth to Muskrat Falls -28/6/75-4/7/75;
II -Muskrat Falls to Gull Isla.nd -3/8/75-24/8/75;
III-Gull Island to Devil's Hole, Winokapau Lake-21/6/76-29/7/76;
IV -Winokapau Lake -31/7/76-5/8/76;
V-Winokapau Lake to·the Churchill Falls tailrace.-17/7/75-6/8/75.
WATER CHEMISTRY
Water samples, generally two from each station and·one from the mouth of
major tributaries, were drawn from the subsurface, stored.in polyethylene bottles,
and analyzed in the St. John's labo~tory. Sample sites ar.:e presented in Appendix
I. The pH was determined elec.trometr:i.cally. Specific conductance was determined
with a Yellow Springs Instruments conductivity bridqe. :;v,Tdta1 hardness, expressed
as ppm calcium carbonate, was measured by means of the ethylenediamine tetraacetic
acid (EDTA) method (American Public Health Association et al. 1971) with calmagite
substituted as an indicator. Total alkalinity was determined by potentiometric
titrations (American Public Health Association et al. 1971). The concentration
of calcium was determined with a Jarrell-Ash atomic-absorption spectrophotometer.
Turbidity was determined with a Hach Chemical Co. laboratory turbidimeter model
2100. Chloride concentrations were measured by means of the mercuric nitrate
method (American Public Health Association et al. 1971).
FISH CAPTURE
·~ r "'t:. ::·
Each study section of the river was fished with gangs of 47 m·~bn~ gillnets
of stretched mesh size 3.8, 5.1, 7.6, 10.2, or 12.7 em. Typically each gang of
nets was composed of all mesh sizes. In several instances, as a result of space
constraints or in an attempt to avoid overfishing, some mesh sizes were deleted.
Nets were fished overnight on bottom or, occasionally, on the surface. Gillnet
locations are shown in Appendix I. Fish were angled at several locations as
well.
5
CATCHES
Catches were reported as total numbers and weight of gillnetted fish and as
numbers and weight per unit effort. A unit of effort was defined as one 47 m
gillnet comprised of all mesh sizes fished overnight for an approximate 24 h
period. Thus equal emphasis was placed on each mesh size fished. so that catches
were reported on the basis of an equal period of effort by each mesh size.
GROWTH IN LENGTH
Fork lengths or, in the case of burbot, total lengths to the nearest
millimetre were obtained from all fish. Scale sampies or, in the case of
burbot, otoliths were obtained from the catch or a subsample representative of
the fish lennths obtained. Scales were removed from above the lateral line just
posterior to the dorsal fin. Scales were examined with a Baosch and Lomb microprojector
at a magnification of 43 diameters. Otolith cross-sections were examined with a
microscope. An age was assigned to each fish equal to the number of completed
annuli as descri.bed by Tesch (1971). Fish in their first year of life were
considered members of age-group 0 or age 0 while fish in their second year were
considered to be members of age-group 1 or age 1 and so on. In the case of
burbot and in these instances where only small numbers of fish were captured,
growth in length was reported as the mean length of each age group at capture.
For the remainder, the following back-calculation procedure was used to compensate
for apparent differences i.n growth resulting from the different times of capture
of the fish.
A scale from each aged fish was measured from the focus to the scale
margin and to each annulus along the anteriormost radius. With the data on each
species separated .by study section, the relationships between fish length and
magnified scale radius were calculated by least-squares regression. P,verages,
rather than fncH-vi..du.al values, of the variates were employed with several data
sets to give equaY·weight to less numerically represented portions of the data.
In the case of obvious curvilinearity of a relationship, double logarithmic
transformations were employed. The resulting equations (Append.ix IV) were then
solved for the various annulus measurements to calculate the average lengths of
the fish at the end of each full year of life.
GROWTH IN WEIGHT RELATIVE TO LENGTH
Fish were weighed on a triple-beam balance to the nearest gram,
or if weights were more than 2000 g, on a chatillion scale to the nearest 10
grams. Length-weight relationships were obtained by least-squares regression of
the logarithms of weight on the logarithms of length using all data or a representative
(by length) subsample of each species in each study section.
SEX RATIOS AND MATURITY
Sex and maturity were determined by macroscopic examination of the gonads.
Sex ratios were calculated for the total catch or a representative subsample (by
length) of each species from each river section. Data were combined and an
·overall sex ratio of each species in the river was calculated. A chi-square
(x 2 ) test was then applied to test for a significant departure from a 1:1 sex ratio.
6
The state of sexual maturity of individuals in the total catch or a subsample
representative of the lengths obtained was determine~ for each species in most
river sections, depending on the expertise of the surveyors. Maturity was
categorized as immature or mature. A mature fish was defined as one that was
going to spawn in the year of capture or that had previously spawned. Fish
categorized by both sex and maturity were examined with respect to length. No
obvious or consistent differences in length at maturity were apparent between
fish of different sexes or from different river sections. Accordingly, all
available data from each species were grouped by length intervals to obtain an
estimate of length at maturity in the Lower Churchill River as a whole. Corresponding
ages were than obtained from the age-length relationships.
FOOD STUDIES
Food items in the stomachs of the catch of a particular species (or a
random subsample of· each species) from each river section were determined. The
number of stomachs containing each food item was expressed as a percentage of
the number of stomachs examined.
SELECTION BY GEAR
The gillnet mesh size in which each fish was captured was recorded in river
sections above Muskrat Falls. Average length, weight, age and catch per unit
effort of fish obtained by the different mesh sizes within the individual river
sections and in the river as a whole above Muskrat Falls were calculated. Data
were also presented by means of length and age-frequency distributions of fish
captured in the various mesh sizes above Muskrat Falls.
f~ORTALITY RATE
Instantaneous (M) and annual (A) mortality rates for the different species
were obtained from least-squares regression of log number of fish on age as
outlined by Ricker (1975). As sample. sizes were inadequate to provide reasonable
estimates in most individual river sections, all data obtained by gillnets above
Muskrat Falls were combined with the assumption that natural mortality rates
were reasonably constant throughout the river. As negligible fishing pressure
occurs upstream of Muskrat Falls, it can be assumed that these mortality rates
are natural mortality rates.
POTENTIAL FISH YIELDS IN THE PROPOSED RESERVOIRS
Quantitative estimates of potential fish yields in the proposed reservoirs
were based on the Ryder (1965) and Gulland (1970) models. Total potential fish
yields were estimated using the morphoedaphic index (i.e. tot.al dissolved
solids in ppm (TDS) divided by mean reservoir depth in metres (Z)) according to
the relationship outrined by Ryder et al. (1974):
Total yield (kg/ha/yr) = 0.966JT;s
7
The components of this yield were estimated using Gulland's (1970) model relating
potential yield to the instantaneous natural mortality rate and theichthyiomass
of exploitable stocks. The computations are similar to those employed by Ryder
and Henderson (1975) to estimate long-term fish yields in the Nasser Reservoir,
Egypt. Component yields were related to total yield by:
Yield of species i (kg/ha/yr) = MiBi x Total yield
tMiBi
where M. = instantaneous natura 1 .marta 1 ity rate of species i; 1
B. =relative biomass of species i.
1
Relative biomass of a given species was estimated from the proportion of the
weight or that species obtained per unit effort to the total weight obtained per
unit effort in Winokap&u Lake. Winokapau Lake's fish population was chosen as a
model for those of the two proposed reservoirs as Winokapau Lake i? that section
of the Lower Churchill River which will most closely resemble the two reservoirs
in characteristics such as shape, thermal regime, and water quality.
HABITAT DESCRIPTION
PHYSICAL
The Lower Churchill River flows from the Churchill Falls hydroelectric
generating station's tailrace through Lake Winokapau over Muskrat Falls, a
natural barrier to sea-run fish, and into Lake Melville at Happy Valley, a
distance of some 320 km. Prior to the natural flow being regulated by the
Churchill Falls hydroelectric development since 1971, the Lower Churchill had
"one of the greatest and wildest descents of any stream in eastern America"
(Riche 1965).
Detailed biophysical descriptions of the Lower Churchill R1ver
valley can be found in Thurlow et al. (1974) and Lopoukhine et al. (1978). In
general, the river is comprised of three major physically distinct habitat
types: the region downstream of Gull Island (Sections I and II); the regions
immediately above and below Winokapau Lake (Sections V and III); and Winokapau
Lake (Section IV).
The river bottom is primarily gneiss bedrock with localized outcrops of
sandstones afld shales .. The most readily noticeable feature of Section I below
Muskrat Falls is the predominance of sand on the shoreline and river bottom
(Fig. 2). Sectton II,,·from t·1uskrat Falls to Gull Island has a sandy bottom but
a higher current speed has exposed more rock and gravel (Fig. 3). Sections I
and II are the shallowest stretches of the river. · With the exception of Winokapau
Lake, the river upstream of Gull Island flows rapidly over a rocky bottom. The
highest water velocities are found in Section III (Fig. 4), the stretch of river
from Winokapau Lake to Gull Island and Section V, below Churchill Falls (Fig. 5).
Winokap~u Lake, a deep lake some 56 km long, is characterized by an extremely
steep rocky shoreline and the lowest water velocity of the five study sections
(Fig. 6).
Fig. 2 . Sectton I downstream of Muskrat Falls.
---------------·--· .. ------·---···--
Fig. 3. Section II between Gull Island and
Muskrat Fa 11 s.
9
Fig . 4. Section III near Gull Island.
?" :~~~~-=~~ .t ~~
____ ... ::,~:r
Fig. 5. Section V downstream of Churchill Falls.
10
. Fig. 6. Winokaupau Lake .
11
WATER QUALITY
The Lower Churchill River is oligotrophic (Table 3). Its water is similar
in chemical composition to lakes of Labrador (Duthie and Ostrofsky 1974, 1975)
and to the least biologically productive waters of the world (Wetzel 1975). With
calcium concentrations less than 10 ppm, it can be termed calciYm deficient
(Wetzel 1975).
The tributaries of the Lower Churchill vary in chemical composition, but on
the whole are characterized by a greater degree of oligotrophy than the Lower
Churchill itself (Table 4).
DISCUSSION
Apart from the previously documented new dimensions of the reservoirs,
physical changes are difficult to predict. However, certain generalizations can
be made. As a result of the construction of dams at Gull Island and ·Muskrat
Falls, the upstream river-lake complex will be changed into more of a lake-like
environment with a probable Y'eduction in habitat diversi.ty. As the rate of flow
decreases, or becomes more regular, temperature and chemical stratificQ,tion will
become more evident throughout the system. The increased loading of sediment
and detritus after flooding may produce anoxic conditions in the deeper water of
the reservoirs. Clear-cutting of the forest prior to flooding may lessen this
problem somewhat and speed up biological stabilization of the reservoir.
The proposed reservoirs, in the long term, will likely have a surface water
quality similar to their major water source, the Smallwood Reservoir, and the
only lentic environment on the river, Winokapau Lake. The Smallwood Reservoir•s
Lobstick and Sandgirt Lakes were characterized in August of 1974 by a pH of 6.5,
a conductance of 20.7 micromhos/cm, a total hardness of 10.6 ppm, a total alkalinity
of 8.3 ppm, a calcium concentration of 2.1 ppm, a turbidity of 1.2 JTU, and a
chloride concentration of 0.8 ppm (Bruce 1975). Turbidity will likely decline
as a result of settling of sediments in the reservoirs after initial increases
as was the case.with the Smallwood Reservoir (Duthie and Ostrofsky 1975).
The Lower Churchill River below the proposed Muskrat Falls Reservoir will
have a similar but more regulated flow. The water chemistry will probably
approximate that of the Smallwood and Lower Churchill Reservoirs with the most
noticeable change being, in the long term, a reduction in turbidity as solids
are precipitated in the reservoirs.
Expected changes in the fish populations as a result of these changes in
the physical and chemical environment are described in the following sections.
Table 3. Water quality of the Lower Churchill River, June-August 1975-76. Means and ranges are given~ (Individual
station measurements are presented in Appendix II).
Total Total
River Conductance hardness alkalinity Calcium Turbidity Chloride
section pH (~hos/cm at 25°C) (ppm) (ppm) (ppm) (JTU) (ppm)
I -River mouth to 6.4 17.1 7 5 1.0 10.8 1.0
Muskrat Fa 11 s 6.0-6.8 14. 3-19.1 5-10 4-6 0.8-1.4 3.5-20.0 1. 0-1.0
II -Muskrat Falls to 6.2 19.0 8 6 1.3 5.6 1.1
Gull Island 6.0-6.5 18.0-20.9 6-9 3-7 1.1-1.5 3.5-9.0 1.0-2.0
III -Gull Island to 6.3 18.8 9 6 1.6 1.1 0.7
Devil• s Hole, 6.2-6.6 17.0-22.0 7-10 4-8 1.1-2.0 0.5-4 .. 0 0.6-0.8
Winokapau Lake
IV -Winokapau Lake 6.3 19.5 9 6 1.5 1.2 0.6
6.2-6.5 18.0-22.0 7-10 5-7 1.3-1.8 0.6-2.2 0.6-0.7
V -Winokapau Lake to 6.4 20.4 9 7 1.4 1.5 0.7
Churchi 11 Falls 6. l-6. 5 . 13.2-26.4 6-12 4-8 0.8-2.3 0.3-3.7 0.5-1.5
tail race
1-V -'Entire River 6.3 18.9 8 6 1.4 3.4 0.8
5.8-6.6 . 13.2-26.4 5-12 3-8 0.8-2.3 0.3-20;0 0.5-2.0
_.
N
Table 4. Water quality of major tributaries of the Lower Churchill River, August 31, 1976. (Tributaries are
listed in order of increasing distance upstream from Goose Bay.)
Mouth
location Total Total
Tributary (river Conductance hardness alkalinity Calcium Turbidity Chloride
No. Name section) pH (~hos/cm at 25°C) (ppm) (ppm) (ppm) (JTU) (ppm)
1. Caroline Brook I 6. 1 18.0 10 4 1.3 6.5 1.5
2. Mackenzie River I 6.4 15.0 7 4 1.1 1.5 1.5
3. Lower Brook II 6.5 15.0 7 3 1.1 4.0 1.5
4. Upper, Brook II 6.0 15.0 7 3 1.3 5.0 1.5
5. Pinus River II 6.3 11.0 7 2 1.2 ].0 1.0
6. Unnamed II 6.2 17.0 8 4 1.3 1.2 2.0
7. Unnamed II 5.9 1,2. 0 5 1 0.7 1.2 1.5
8. Minipi River III 6.3 14.0 7 2 0.7 0.8 1.0
9. Dominion River III 6.2 13.0 7 2 1.0 1.0 1.0
1 o. Cache River III 6.0 12.0 6 1 0.9 1.3 1.0
11. Shoal River III 6. 1 10.0 6 2 1.0 1.2 1.0
12. Fig River IV 6. 1 11.0 6 3 0.7 1.2 0.9
13. Elizabeth River v 6.4 15.0 7 4 1.0 1.5 1.2
14. Metchin River v 5.6 12.0 6 1 0.8 1.2 0.4
15. Unnamed v 5.8 12.0 7 1 1.8 1.4 1.0
Averaged data 6.1 13.5 6.9 2.5 1.1 2.0 1.2
_.
w
14
RELATIVE ABUNDANCE OF FISH
TOTAL CATCHES
In the river as a whole, one unit of gillnet effort yielded 5.5 fish
weighing 3.2 kg. Eleven of the 19 species reported present by Scott and Crossman
(1973) were captured. These data are similar to comparative catch per unit
effort statistics of 5.0 fish weighing 3.3 kg from the main body of the Smallwood
Reservoir (Bruce 1975). Nine species were taken in the reservoir. Catch rates
and number of species captured varied from section to section within the river
(Fig. 7). Total catches and number of species captured were greatest in those
river sections upstream of Gull Island and least in Section II, the area of the
proposed Muskrat Fa 11 s reservoir. Greater catches were associated with the
capture of a greater number of species (Appendix III).
SPECIES COMPOSITION
Fig. 7. Catches of all fish species
from the Lower Churchill River, June-
August, 1975-76. (Number of species
captured in each fiver section is
indicated).
The most numerous species in the catch from the river as a whole were, in
order of abundance, longnose suckers, lake whitefish, white suckers, brook
trout, and northern pike (Fig. 8). Their relative abundance varied greatly from
section to section within the river and each river section was in contrast to
the Smallwood Reservoir. In catches from the Smallwood Reservoir, lake whitefish,
longnose suckers, lake trout, and round whitefish were·most numerous (Bruce
1975).
a
B
:z: en
i::
Ia.
0
3·0
2:0
1·0
0·0
4·0
ar: 3·0 ....,
IZI
::1
:::1 z
... z = ar: 1·0 ....,
Q.
:z:
~ u 0·0
15
"'-! ::z:: z ::z:: Q "'-! ~a:: ~ a: a: (I) :ga: w QLi: 1-z iw ...,.w ."'-~w ~~ ::z:: 0 ~ 1-ZUJ
1-UJ ZUJ IZI 1.1.1:::1 ~~ ~~ :.:!:: t: ~ QO =:.: ;::,!:: a: ~ ::.0::0 :::1 ~::z:: ::Z:::::~ a: a: 0-o::z:: :::1 ~= 0:::1 .;..10 _,,. 31(1') IZII-ZQ. a: !I: IZI 0 _,,_ -'"'
SECTION I
C PUE z 6·5 FISH
SECTION Ill
C P U E s 8·6FISH
(0·1 (0·1
SECTION V
C P U E 2 6·9 FISH
::z::
(I)
Li: a:
WUJ ww :.:1-
1-:0.: 0:::1 :.:!:: -(..l co ~::z:: ::Z:::::~ a: a:: _,,. !I: (I) IZI!-
.....
z :z: Q a: (I) ..... QLi: 1-~ ::z:: 0 ,_...., z"'-~ IZI =:.: :::~!:: a: ~ 0-o:z: :::1 ZQ. a:31! IZI 0
SECT{ON II
C P U E = 2·5 FISH
SECTION IV
C P U E = 7·0 FISH
SECTIONS 1-V
C P U E • 5·5 FISH
1-
~5 ~a:: _,,_
(0·1 (C)-f
Fig. 8. Catch in numbers of major fish species in the
Lower Churchill River, June-August~ 1975-76.
16
In terms of weight, northern pike was most abundant in· the catch from the
river as a whole, followed by lake whitefish,.longnose suckers, white suckers,
and brook trout (Fig. 9). Reiative abundance by weight varied greatly from
section to section in the river. In the Smallwood Reservoir, lake whitefish
made up the greatest portion of the catch followed by lake trout, Jongnose
sucker, and northern pike (Bruce 1975). ·
0·2
0·6
0·4
0·2
o-o
SECTION I
CPU E a 2·6 kg·
SECTION Ill
CPU E a 3•8 kg
SECTION V
CPU E 2 4·3 kg
SECTION II
C P U E • 2·1 kg
SECTION IV
CPUE•5·0kg
·SECTIONS I -V
C P U E = 3·2 kg
Fig. 9. Catch in weight of major fish species in the Lower
Churchill River, ~une-August, 1975-76.
0
0
0
0
B
0
0
.. u
•
D
0
0
0
17
In addition to the species indicated in Fig. 8 and 9 , two rainbow smelt
were captured in Section I. Three lake chub were taken in Section III and
identified in the stomachs of fish from Section IV. Threespine sticklebacks
were identified in stomach contents from Sections I, IV, and V. Unidentified
species of sculpins were found in the stomachs of fish from Sections III
and V.
DISCUSSION
There is some evidence that the overall fish production in the proposed
reservoirs will be greater than exists, on the average, throughout the Lower
Churchill. The greater catches and the greater numbers of species obtained
above Gull Island suggest that adequate numbers of viable species will be present
to enable colonization of most available habitat in the Gull Island Reservoir.
Also, the comparatively large catches and number of species in Winokapau Lake
(that area of the Lower Churchill system most closely resembling both reservoirs)
suggests that fish biomass and hence production will increase after impoundment.
Several species reported as present in the river by Scott and Crossman (1973)
were not identified during the survey. This was likely a result of their small
size and resultant non-susceptibility to capture by gillnets or, in the case of
sea-run species, their scarcity in the river during the survey.
After impoundment, physical and chemical conditions in the Teservoirs will
most closely resemble those of Winokapau Lake. This suggests relative abundance
and species coJllposition will also resemble those in the lake at the present
time. Jf excessive anomalous environmental .conditions are not created and this
occurs, the most abundant species in t~e ~~servoirs, in terms of numbers ~nd
weight, will be longnose suckers followed by white suckers and lake whitefish.
No ouananiche or l?ke trout were captured in Section II, the area proposed
for the Muskrat Falls Reservoir. This suggests that, if optimal use is to be
made of this reservoir and all habitats are to be used, these species should be
introduced if they do not colonize the reservoir themselves. This should result
in a fish community composition in both reservoirs similar to that in Winokapau
Lake; again providing that excessive anomalous environmental conditions are not
created. ·
After impoundment, the community structure downstream of the Muskrat Falls
Reservoir should not change significantly provided that the flow of water is ·
maintained.
NORTHERN PIKE
CATCHES
In the river as a whole, 689 gillnets fished overnight caught 265 northern
pike with a total weight of 549.8 kg (Fig. 10). This corresponds to 0.4 fish
weighing 0.80 kg/net night with equal weight being given to each mesh size
fished. Captured pike had a mean length of 63.6 em, a mean weight of 2.08 kg,
and a mean age of 8.5 years.
18
Fig. 10. ~lorthern pike.
Catches were variable from sec t ion to section within the river (Fig. 11).
In terms of number and weight obtained per net night, Section II was the most
productive and Section III the least productive .
0 7
~0 6
0 5
0 '
0·3
0 2
01
/l'
·I
, 'I
I.
. ~·· ~·· ,,· ~
O·O '--1-:;SE-.-::CT J:::'ON'---'':-;SEC:;::TI:;c-01, L-J=SEC:=::=TIO:='N '--'-;:;S E C:;:TI:;c-O N '---'=~
I I J Ill I V
Fig. 11. Catches of northern pike in five sections of
the Lower Churchill River, June-August, 1975-76.
19
GROWTH IN LENGTH
Northern pike in the Lower Churchill River tended to exhibit a declining
growth rate until lengths of about 70 em were reached (Fig. 12 and Appendix V).
Fish of this length exhibited an increase in growth rate suggestive of the
availability of a new food source to fish of this length. On the whole, growth
in length was more rapid than that typically exhibited by pike in northern
Canadian waters but slower that than experienced by the usually fast~growing
southern populations {Scott and Crossman 1973). The rate of growth in. the river
as a whole was a little greater than that observed in the Smallwood Reservoir
(Bruce 1974, 1975).
120 ,...-,.---.--..---.--r-..----r--r--.----.-.-,--,-.-,-...,--,
115
lhl
105
100
95
o----o
o---o
x-x
SECTION I
SECTION II
SECTION IV
SECTION V
O 0 I 2 3 4 5 6 7 8 9 10 II 12 13 14 15 16 17
AGE (YEARS)
Fig. 12. ~rowth of northern pike in
the Lower Churchill River, 1975-76.
Presented for contrast is an approximation
of growth in northern Canadian lakes
(solid heavy line) (Miller and Kennedy 1948)
and Wisconsin lakes (dashed heavy line)
(Van Engel 1940).
Growth rates were variable within the river. Growth in the first four
year of life was similar in all but Sectton I which contained the fastest
growing young fish. Growth rates in later years were similar in all but Section
V which contained the fastest growing older fish. The extremely small calculated
length of age-group 1 fish in Section V was likely an artifact of the methods
employed.
20
The longevity of pike in the Lower Churchill was similar to that usually
observed in slow-:-growing northern populations (Miller and Kennedy 1948). The
oldest fish was in its 18th year.
GROWTH IN WEIGHT
Exponents in the length-weight relationships of northern pike ranged from
2.68 to 3.17 and had a mean of 3.01 (Table 5)~ lower than the range of 3.1-3.9
reported by Bruce (1974, 1975) for pike in the Smallwood Reservoir.
Table 5. Least squares linear regressions of log 10 weight (g) on
log 10 fork length (em) for northern pike from the Lower
Churchill River, June-August 1975-76.
River y Correlation No. of
section intercept Slope coefficient fish
I -2.30 3.11 0.984 55
II -2.25 3.07 0.996 131
IV -2.43 3.17 0.997 18
v -4.52 2.68 0.980 60
Means -2.88 3. 01
SEX RATIOS AND MATURITY
The avera 11 sex ratio indica ted an equa 1 abundance of the sexes, contrary
to the slight relative abundance of females observed in southern Ontario catches
over the summer months (Casselman 1975). Numbers of males per female in the
five sections were 0.88-1.62 with an overall ratio of 1.19 (Appendix VI).
Of the 265 northern pike examined,88.3% were mature fish (Appendix VII).
Pike matured at approximately 40 em~ the average length attained by fish in
their fourth to fifth year of life. This is an age at maturity similar to the
usual 2-4 years in the south of Canada, but younger than the usual 5-6 years in
the north (Scott and Crossman 1973).
FOOD STUDIES
Northern pike captured in the Lower Churchill were primarily piscivorous as
is usual for this species (Scott and Crossman 1973). Suckers and lake whitefish
were the most frequently identified food items (Table 6).
21
Table 6. Percentage occurrence of major food items in the stomachs of
northern pike in the Lower Churchill River, June-August 1975-76.
River section
Food Item I II III IV v I-V combined
Fish remains 38.2 18.7 100.0 44.4 15.0 26.5
Catostomus sp • 9.1 12.0 33.3 47.5 20.6
Coregonus aZupeaformis 14.6 30.0 10.6
Gasterosteus aauZeatus 10.9 11.1 4.2
Lota Zota 4.0 1.6
Esox Zuaius 4.0 1.6
Insect remains 16.7 1.6
Detritus 16.7 1.6
Diptera (larvae) 16.7 1.6
Frosopium ayZindraaeum 5.0 1.1
Ostracoda 5.6 0.5
Cottus sp. 2.5 0.5
Number of stomachs
examined 55 75 1 18 40 189
Number of stomachs
empty 19 43 0 4 8 74
SELECTION BY GEAR
On the whole, mean lengths, weights and ages of captured pike tended to
be greater with increasing mesh size (Fig. 13 and 14; Table 7). These trends were
also visible within the individual river sections (Appendices VIII and IX). The
most efficient mesh size, in terms of number and weight of fish captured per
net night, was 10.2 em. One net night of fishing with this mesh size yielded
0.6 fish weighing 1.46 kg. Pike captured by this mesh size were all age 5
and over and 50 em or larger.
MORTALITY RATE
The natural mortality rate (A = 0.26) of pike upstream of Muskrat Falls (Fig. 15)
was lower than the 0.38-0.44 annual mortality rate of pike in commercially
fished Lake Ontario (Wolfert and Miller 1978).
lO
lO
10
lO
ili
22
3-8 em MESH
H • 42
5·1 ca MESH
H • 36
7·6 ca MESH
N• 60
10·2 ca IIESH
H • 6<4
i:ZO
~ 10
i 1~
so
TO
so
'0
40
10
lO lO
3-8 -IN,., MESH
H • 213
~.,.--,-......,---,---, ..,...-,--,j
·····----·--· ···-··-···· ... -··. -v.-'"1....,........__....,, 5 I em MESH 1
~.· . N•35 -1 J~• --~~--~---L--~~--~7=6~em_··~ME=~~~--~-===_,1
!5 i N • 57 l
!0 t-,.---;-J'1
sr r -~
0 }----'--=·-····· ...... ___ n,_,.,-,,=='------'-'-1
I
15 !-
10,...
5!-
10·2 em MESH
N • 63
!2·7 em MESH
N • II
9~------~==~~======~~~~~
35 ~
I 2
Fig. 13. Length-frequency distribution
by gillnet mesh size of northern pike
from the Lower Churchill River above
Muskrat Falls, June-August, 1975-76.
Fig. 14. Age-frequency distribution
by gillnet mesh size of northern pike
from the Lower Churchill River above
Muskrat Falls, June-August, 1975-76.
23
Table 7. Catch statistics of northern pike from Sections II-V of the Lower
Churchill River, June-August 1975-76.
Mesh
size
(em)
3.8
5. 1
7.6
10.2
12.7
No. of
net
nights
:::~
::~
HI-
I
3·0 r-
2 9~
2·6 f-
Z"4~
H~ i2·t .. :::~
1·4t-
12t-'
i tol
oar
0 .~
0·4~
' 0·2'
107
107
109
109
107
0·0 '
No. of
fish
caught
42
36
57
64
11
No. of Mean
fish per . 1 ength
net night (em)
0.4 49.9
0.3 55.8
0.5 58.4
0.6 66.8
0.1 77.1
l j. ' I I 1 I
M • 0·30· l A • 0·26
r • 0·97
AGES 9-15
I
j
~
l
l
-i
' l
I l 4 5 6 7 9 3 10 'I 12 13 14 15 16 17
AGE GROUP I YEARS I
Weight
Total Mean per net Mean
weight weight night age
(kg) (kg) (kg) (yr)
64.1 1. 53 0.59 6. 1
71.3 1.98 0.67 6.9
96.4 1.69 0.88 7.3
159.2 . 2.49 .1.46 8.3
40.5 3.68 0.38 10.5
Fig. 15. Catch curve of northern pike
from the Lower Churchill River above
Muskrat Falls, June-August, 1975-76.
24
DISCUSSION
As reviewed by Machniak (1975a), reproduction, growth, and abundance of
northern pike generally improve after the impoundment of waters. Later,
reproductive success fluctuates with water level regulation while growth and
abundance are dependent upon the supply of foraqe species.
Northern pike usually spawn on heavily vegetated floodplairis and
bays, preferring water depths ot 50 em or less. Impoundment of the Lower
Churchill may create many new possible spawning sites. However, drawdowns
in excess of 50 em from the time of spawning soon after ice-out to about
a month later when the young become mobile will be deleterious. It is likely
that spring drawdown will be an important factor limiting pike reproduction
in the reservoirs.
Pike growth will likely exhibit greater variation than exists at
the present time. While growth below the site of the Muskrat Falls dam
should remain the same due to a similar physical, chemical, and biological
environment, growth in the areas of the reservoirs will likely improve. The
larger bodies of slow-moving water and likely abundance of forage fishes such as
whitefish and suckers ·should produce faster-growing individuals. Pike biomass
will likely be made up of faster-growing individuals rather than a larger number
of slow growers since reproduction will often be impeded by drawdown.
I
An additional indication of a faster growth rate in the reservoirs is the
comparatively high exponent in the length-weight relationship in Winokapau
Lake. As conditions in the river approach those of Winokapau Lake, g\'owth in
weight with respect to length should more closely resemble that in the lake and
increase.
There is some indication that pike production will increase in the reservoirs.
The ·habitat of pike is usuallY slow-moving, heavily vegetated rivers or weedy
bays of lakes. Also, pike catches in the Lower Churchill were least in the
rapid waters of Section III below Winokapau Lake.
Of possible concern to fishermen on the reservoirs is the infestation of
pike by the parasite, Triaenophorus arassus. This parasite uses the commercially
valuable lake whitefish as its intermediate host and renders the flesh less
desirable. An increase in the pike population in the reservoirs may heighten the
potential for infestation by this parasite.
If a commercial pike fishery is started on the new reservoirs, 10.2 em may
prove to be the most beneficial mesh size for gillnets. Since all of the pike
captured by the 10.2 em mesh were 50 em or greater, it can be expected that,
after the spawning run, this most efficient mesh size would capture relatively
few fish that had not spawned at least once.
25
LAKE WHITEFISH
CATCHES
In the river overall 689 gillnets fished overnight captured 837 lake
whitefish with a total weight of 469.0 kg (Fig. 16). Giving equal weight to
each mesh size fished, this corresponds to an average of 1.2 fish weighing
0.68 kg/net night. Captured whitefish had a mean length of 32.8 em, a mean
weight of 0.56 kg, and a mean age of 7.0 years.
Fig. 16. Lake whitefish.
26
Whitefish catches within the river ranged from 0.36 kg/net night in the
site of the Muskrat Falls Reservoir (Section II) to 0.98 kg/net night at Section
V below Chnrr:hill Falls (Fig. 17).
"' Hr
~ I·Of-.
§ O·gt-
SECTION SECTION
Ill IV
Fig. 17. Catches of lake whitefish
in five sections of the Low.er Churchi 11
River, June-August, 1975-76.
On the average, catches above the site of the Gull Island dam tended to be
greater than those from the two river sections below the dam site.
Mean lengths, weights, and ages of captured fish tended to be similar in
all sections except those from below Muskrat Falls (Appendix VIII). Fish from
this section tended to be the smallest and youngest fish.
GROWTH IN LENGTH
Lake whitefish in the Lower Churchill River tended to exhibit a declining
growth rate with age (Fig. 18 and Appendix V). On the whole, growth
in length was within the range previously described for whitefish over the whole
of their zoogeographic range and slower than that usually seen in lightly exploited
populations (Healey 1975). The rate of growth in the river as a whole was lower
than that experienced by whitefish in the Smallwood Reservoir (Bruce 1974,
1975).
46 r--r--r--r---r-;-r-r--r--r--r---,--r-r--r--r-,
::~ 40
38
36
34
32
•-• SECTION I
o----o SECTION II
A-A SECTION Ill
<J----o SECTION IV _,
x-. SECTION V
27
Fig. 18. Growth of lake whitefish in
the Lower Churchill River, 1975-76. Presented
for contrast is the total range in
growth (solid heavy lines) for whitefish over
the zoogeographic range (Healey, 1975).
Growth rates were variable within the river •. Growth wa$ faster upstream of
the proposed Gull Island dam than below. In the three sections above the site
of the proposed dam, growth tended to be slower with greater distance upstream.
The most rapid growth occurred between Gull Island and Winokapau Lake. Below
the Gull Island site, growth was faster with greater distance upstream.
The maxim~m age of lake whitefish was similar to that usually recorded over
the range (Scott and Crossman 1973; Healey 1975); with one fish being in its
18th year and one in its 21st.
GROWTH IN WEIGHT
Exponents in the length-weight relationships of lake whitefish ranged from
2.92. to 3.30 with a mean of 3.11 (Table 8). The avera,ge value was at the low
end of the usual range of about 3.1-3.5 (Healey 1975) but the same as that of
whitefish in the Smallwood Reservoir (Bruce 1974, 1975).
Consistent with growth in length, exponents tended to be lesser with greater
distance upstream in the three sections above the Gull Island dam site but
greater -with greater distance upstream bel ow. the dam site.
28
Table 8. Least squares linear regressions of log 10 weight (g) on
log 10 fork length (em) for lake whitefish from the Lower
Churchill River, June-August 1975-76.
River y Correlation No. of
section intercept Slope coefficient fish
I -1.88 2.97 0.986 148
II -2.33 3.30 0.995 128
III -2.23 3.23 0.960 119
IV -2.06 3.11 0.979 58 v -4.75 2.92 0.976 152
Means -2.65 3.11
SEX RATIOS AND MATURITY
The overall sex ratio indicated an equal abundance of the sexes as is usual
for this species (Machniak 1975b). Numbers of males per female were 0.57-1.38
with an overall ratio of 0.95 {Appendix VI).
Of 737 lake whitefish examined, 84.3% were mature (Appendix VII). The
smallest length interval in which more than 50% of the individuals were mature
was 20.0-21.9 em; having 57.9% mature individuals. This interval corresponded
to the length attained by fish in their third to fifth year of life. Some
immature individuals were found in each 2 em interval up to 42 em. These data
are low compared to the wide range in length at maturity of 20-40 em in other
northern populations (Healey 1975) and the usual age of 4 years at which most
whitefish spawn (Machniak 1975b).
FOOD
Lake whitefish captured in the Lower Churchi 11 River fed primarily on
benthic invertebrates as is usual for this species (Scott and Crossman 1973).
Insects were the major food source followed by occasional arachnids, crustaceans,
molluscs and fish (Table 9).
SELECTION BY GEAR
Mean lengths, weights, and ages of captured lake whitefish tended to be
greater with increasing mesh size,when the data were combined (Fig. 19 and 20,
Table 10) and in the individual river sections {Appendices VIII and IX). The
most efficient mesh size was the 7.6 em; catching 2.2 fish weighing 1.43 kg/net
-night. It captured fish over almost the whole range of ages and lengths in the
total catch. Ninety-nine percent of the whitefish captured by this mesh size
were age 4 and over and 97% were 30 em or larger.
29
Table 9. Percentage occurrence of major food items in the stomachs of
lake whitefish in the Lower Churchill River, June-August 1975-76.
River section
Food item I II III IV v I-V combined
Insect remains 76.0 54.7 37.1 25.7 66.7 52.7
Detritus 34.7 25.3 47.1 38.6 39.7-37.0
Trichoptera 21.3 62.9 4.3 33.3 24.2
Diptera (pupae) 22.7 14.7 14.3 35.7 24.4 22.3
Diptera (larvae) 57.3 22.7 2.9 12.9 12.8 22.0
Plecoptera 38.6 22.9 34.6 19.0
Hydracarina 40.0 9.33 12.9 16.7 16.0
Cladocera 12.0 14.3 29.5 11.4
Ephemeroptera 1.4 7.1 38.5 9.8
Invertebrate eggs 42.9 1.4 8.4
Mollusca 8.5 22.9 1.3 6.3
Ceratopogonidae 18.7 10.0 5.7
Hymenoptera 11.4 2.9 11.5 5.2
Lepidoptera 2.6 0.5
Fish remains 5.7 1.4 -5.1 2.5
Co1eptera 7. 1 2.9 1.3 2.2
Hemiptera 2.9 .5. 1 1.6
Fish eggs 1. 4 1.4
Odonata 5.7 1.1
Copepoda 2.9 0.5
Lota Zota 1.4 0.2
Gaste~osteus aauZeatus 1.4 0.2
Cottus sp. 1.4 0.2
Number of stomachs
examined 75 75 70 70 78 368
Number of stomachs
empty 5 15 6 18 14 58
30
. IOO,---.,...--.,...--...,.--...,..--...,.----r----,
Hem MESH
N' 40 so
o~-~~~~~---~5~-1-c-m~M~Es=H~~
so N' 74
0~-----~~~~~==~------~
200
ISO
100
so
7-6 em MESH
N, 239
0~--~==~~~~~~
0~---------===~:=~--~~
~00
350
300
2SO
200
ISO
100
so
3-8 -IN em MESH
N '543
0~~~~~~~~~~--~~
0 10 zo 30 40 50 60 70
INTERVALS OF FORK LENGTH (cml
JO ,--,--,.-.,.--.--r-·,...------,--,--,--,.-,--.--,.--r--r--:
zo
10
10
40
JO
20
JO
lB em MESH
N' 37
Hem MESH
N' 222
~0~---~------------~~--~-----~
i!; 20 lo-2 em MESH
"' I H' 128 I ': ~--~-___ ......_ _______ __;'--::-:--:::::::-------1
10 ~ ~Z·! i'" MESH
H-IHClll MESH
H' 459
I 'Z l 4 5 6 7 8 9 10 II 12 !J 14 15 16 • i7 J!il 19 ZO
.o<;£ GROUP !YEARS!
Fig. 19. Length-frequency distribution
by gillnet mesh size of lake whitefish
from the Lower Churchill River above
Muskrat Falls, June-August, 1975-76.
Fig. 20. Age-frequency distribution by
gillnet mesh size of lake whitefish from
the Lower Churchill River above Muskrat
Falls, June-August, 1975-76
31
Table 10. Catch statistics of lake whitefish from Sections II-V of the Lower
Churchill River, June-August 1975-76.
Mesh
size
(em)
3.8
5.1
7.6
10.2
12.7
4-4
H
4·0
].8
H
H
H
3·0
11·.:~
1·0
0·8
0·4
No. of
net
nights
107
107
109
109
107
.
No. of No. of Mean
fish fish per length
caught net night (em)
40 0.4 25.3
74 0.7 30.7
240 2.2 36.2
178 1.6 37.5
11 o. 1 40.1
M • 0·40
A • 0·33
r • 0·48
AGES 9-13
0·6~
H i ~~~~~~~~1-71~1 ~~~~~,~-~·~·~·~ O O 0 7 8 9 10 II 12 13 14 15 16 fi 18
AGE GROUP (YEARSI
Weight
Total Mean per net Mean
weight weight night age
(kg} (kg) (kg) (yr)
11.6 0.29 .0. 11 4.5
32.4 0.44 0.30 5.6
155.7 0.65 1.43 8.0
131.8 0.74 1.21 8.3
10.4 0.95 0.09 10.3
Fig. 21. Catch curve of lake
whitefish fro~ the Lower Churchill
River above Muskrat Falls, June-August,
1975-76~
32
MORTALITY RATE
The natural mortality rate (M = 0.40) of whitefish taken above Muskrat
Falls {Fig. 21) was slightly less than the 0.49 average of unexploited northern
whitefish populations (Healey 1975).
DISCUSSION
In his review of the literature on lake whitefish in reservoirs, Machniak
(1975b) has written, " .... river reservoirs will probably develop sizeable
whitefish populations provided conditions are fairly amiable ..... 11
There are indications that the growth rate of lake whitefish will improve
in the Lower Churchill if the river is impounded. The facts that overall growth
is slow in the Lower Churchill and slower than in the Smallwood Reservoir
suggest that as conditions in the river approach those of the reservoir, growth
ratcswill increase. Also, the comparatively rapid growth of whitefish
from Winokapau Lake suggests that as the river becomes more of a lake-like
environment, growth rates will increase.
Catch per unit effort of whitefish in the Smallwood Reservoir was greater,
by a factor of about 4-.7 times, than in the Lower Churchill River (Bruce 1975).
Although it is more difficult to fish a river, this large difference suggests
that production will improve after impoundment. This suggestion is supported by
the usually higher density of benthic food organisms found in rivers after
impoundment (Machniak 1975b).
The attainment of potential whitefish production may be impaired by several
factors. Lake whitefish in Labrador usually spawn in October or November (W.
Bruce, pers. comm.). Although they utilize a variety of habitats for spawning,
they generally spawn in shallow water over clean, hard or stony bottom less than
. 8 m deep. Young usually hatch in April or May and remain in. shallow water until
early summer. Thus~ after a reservoir has been flooded, bank instability, high
water turbidity~ offshore sedimentation and drawdowns may have deleterious
effects on reproduction and yield.
A potential problem for any commercial whitefish fishery on the reservoirs
is an increase in the population of the parasite, TriaenophoPUs arassus. This
may cause marketing problems. These problems may be eliminated by exploiting
northern pike, a final host of the parasite.
If a commercial fishery is started on the Lower Churchill River, there may
be difficulties in harvesting only commercial-size whitefish. The generally
accepted commercial size of 0.9 kg (Scott and Crossman 1973) is greater than the
average weight of fish caught in all but the 12.7 em mesh size. This was the
least efficient mesh size used in the present study. Most of the fish caught in
the 7.6 em mesh, the most efficient, would have spawned at least once. However,
the average weight of individuals taken in this mesh size was only 0.74 kg.
33
LONGNOSE SUCKER
CATCHES
Overall, 689 gillnets fished overnight caught 1191 longnose suckers with a
total weight of 401.5 kg (Fig. 22). A single net night averaged 1.7 fish weighing
0.58 kg. Captured fish had a mean length of 29.6 em, a mean weight of 0.34 kg,
and a mean age of 8.8 years.
Fig. 22. Longnose sucker.
Within the river, catches per net night varied from 0.10 kg in Section II
to 1.44 kg in Section IV (Fig. 23). Catches tended to be less downstream of
Gull Island than they were upstream.
GROWTH IN LENGTH
Ages assigned to longnose suckers age 5 and over are, as in the case of
white suckers, liable to underestimation when scales are employed (Scott and
Crossman 1973). Bruce and Parsons (1979) found no significant differences
between the growth of longnose suckers in western Labrador indicated by scales
and that indicated by fin rays. As determined from scales, longnose sucker
growth in the river as a whole appeared linear (Fig. 24 and Appendix V). The
rate of growth was similar to that in the Smallwood Reservoir (Bruce 1974, 1975)
and near the low part of the range exhibited by this species (Rawson and Elsey
-1950; Reed 1962).
34
50,--,---,.--,--,...-,---,--,--..,.-..,.-,..-,.--,---,--,---.--..--,
48
46
44
42
40
38 I
I
I
I
I
36
34
32
30
I
I
I
I
·-SECTION I
o----o SECTION II c.-c. SECTION Ill
a----a SECTION IV
x-x SECTION V
a
I
I
a~~~~~~~~~~~~~~~~
0 I 2 3 4 5 6 7 8 9 10 II 12 13 14 IS 16 17
AGE {YEARS!
Fig. 23. Catches of longnose suckers
in five sections of the Lower Churchill
River, June-August, 1975-76.
Fig. 24. Growth of longnose suckers
in the Lower Churchill River, 1975-76.
Presented for contrast is growth in the
Northern Saskatchewan River (heavy
dashed line) (Reed 1962) and Pyramid Lake,
Alberta (solid heavy line) (Rawson and
Elsey 1950).
35
Growth rates were variable within the river. Growth was slowest in the
rapid waters of Section V below Churchill Falls and fastest in the slow-moving
waters downstream of Muskrat Falls (Section I) and in Winokapau Lake (Section IV).
The maximum age of longnose suckers was similar to that obtained from
scales by other workers. One fish was in its 20th year as compared to the
maximum age of about 22-24 years (Scott and Crossman 1973).
GROWTH IN WEIGHT
Exponents in the length~weight relationship ranged from 3.08 to 3.35 with
a mean of 3.17 (Table ll). This wa~ the value.reported by Bruce (1974) for
longnose suckers from Jacopie Lake in the Smallwood Reservoir but higher than
the value of 2.8 for fish from Lobstick and Sandgirt lakes in the Smallwood
Reservoir (Bruce 1975).
Table 11. Least squares linear regressions of log 10 weight (g) on
log 10 fork length (em) for longnose suckers from the Lower
Churchill River, June-August 1975-76.
River y Correlation No. of
section intercept Slope coefficient fish
I -2.01 3.08 0.968 157
II -2.09 3.11 0.997 55
III -2.17 3.14 0.992 268
IV -2.24 3.18 0.976 171 v -5.48 3.35 0.985 150
Means -2.80 3.17
SEX RATIOS AND MATURITY
Sex ratios in the individual river sections ranged from 0.24 to 0.75
(Appendix VI). The overall ratio, 0.49 males per female, indicated an overall
relative abundance of the longer-1 iving females. ·
Of 698 longnose suckers examined, 87.4% were mature. On the average,
longnose suckers matured at about 20 em, the length attained by fish in their
sixth or seventh year of life.
FOOD
Longnose suckers from the Lower Churchill River fed primarily on benthic
invertebrates (Table 12), the usual food of this species (Scott and Crossman 1973).
36
Table 12. Percentage occurrence of major food items in the stomachs of
longnose suckers in the Lower Churchill River, June-August 1975-76.
River section
Food item I II III IV v. I-V combined
Diptera (larvae) 49.3 100.0 64.0 72.0 69.3 68.4
Detritus 77.3 100.0 80.0 53.3 57.6
Insect remains 45.,3 94.3 33.3 37.3 62.7 ' 49.9
Diptera (pupa) 13.3 68.6 48.0 6.7 90.7 42.7
Trichoptera 45.7 36.0 5.3 20.0 18.5
Plecoptera 18.7 5.3 16.0 9.0
Hydracarina 1.3 5.3 32.0 8.7
Invertebrate eggs 22.9 1.3 5.3 3.9
Ephemeroptera 5.3 9.3 3.4
Mollusca 10.7 2.4
Coleoptera 5.3 1.2
Hirudinea 8.6 0.9
Copepoda 4.0 0.9
Cladocera 4.0 0.9
Certopogonidae 2.7 0.6
Hemiptera 1.3 0.3
Algae 1.3 0.3
Fish eggs 1.3 . 0.3
Number of stomachs
examined 75 35 75 75 75 335
Number of stomachs
empty 8 0 3 6 3 20
SELECTION BY GEAR
Overall, mean lengths, weights and ages of captured longnose suckers
tended to be greater with greater mesh size (Fig. 25 and 26, Table 13). These
trends were also obvious within the individual river sections (Appendices VIII
and IX). The most efficient mesh size, 7.6 em, yielded 3.9 fish weighing
1.99 kg/net night. All fish captured by this mesh were age 7 and over and 98%
were 30 em or larger.
40
30
20
20
10
60
50
iii
i: 40 ...
0 30
0:
~ 20
i 10
300
200
100
0
300
200
100 2\
0
500
400
::: 1: 300
:; 200
0
600
500
400
300
zoo
100
0
0 10
37
38 em MESH
N • 195
.:I .
5·1 em MESH
N: 224
lz
7-6 em MESH
N • 432
\
10·2 em MESH
N • 48
3·8 -12·7 em MESH
N • 902
' 20 30 40 50 60
INTERVAL~ OF FORK LENGTH (em I
3-8 em MESH
N • 95
5•1 em MESH
N • 137
7-6 em MESH
N • 222
70
\ 0~------_a~~~~--~~~~~~-=~
10
0~------------------~~==~~==------~
70
60
50
40
30
3 4 5
3-8 -12· 7 em MESH
N • 484
6 7 8 9 10 II 12 13 14 15 16
AGE GROUP I YEARS!
Fig. 25. Length-frequency distribution
by gillnet mesh size of longnose suckers
from the Lower Churchill River ·above Muskrat
Falls, June-August, 1975-76.
Fig. 26. Age-frequency distribution by
gillnet mesh size of longnose suckers
from the Lower Cht.•rchi 11 River above
Muskrat Falls, June-August, 1975-76.
38
Table 13. Catch statistics of longnose suckers from Sections II-V of the Lower
Churchill River, June-August 1975-76.
Weight
r~esh No. of No. of No. of Mean Total Mean per net Mean
size net fish fish per length weight weight night age
(em) nights caught net night (em) (kg) (kg) (kg) (yr)
3.8 107 195 1.8 18.9 16.0 0.08 . 0.15 4.7
5. 1 107 224 2. 1 27.3 54.1 0.24 0.51 7.7
7.6 109 432 3.9 34.9 216.6 0.50 1.99 11 .3
10.2 109 48 0.4 40.9 41.4 0.86 0.38 13.0
12.7 107 3 <0. 1 44.0 3.0 1.0 0.03 14.0
MORTALITY RATE
The instantaneous mortality rate (M = 0.57) of longnose suckers in the Lower
Churchill River (Fig. 27) was similar to the 0.55 observed in Great Slave Lake
(Harris 1962).
4-4
4-2
4-0
3-8
H
H
3-2
3•0
2·8
2·6
'"'H ~2-2
1·4
1-2
1·0
0·8
0·6
0·4
0·2
"'. 0·57
A • 0·44
r • 0·93
AGES 12-16
O·O 0 1 2 3 4 5 6 7 8 9 10 II 12 13 14 15 16 17 18
AGE GROUP (YEARS!
Fig. 27. Catch curve of longnose suckers from the Lower Churchill
River above Muskrat Falls, June-August, 1975-76.
39
DISCUSSION
The longnose sucker is an adaptable fish widespread over Canada's north.
A relatively abundant fish in the Lower Churchill River, it should do well in
the new reservoirs.
Upstream of Muskrat Falls, growth rates of longnose suckers should improve
after impoundment as suggested by the faster growth in the two slower velocity
sections at present. If conditions downstream of the dam remain similar, it is
to be expected that growth rates will also.
Production of longnose suckers is likely to increase if the usual increase
in benthic invertebrates occurs after impoundment. Longnose suckers will
likely form the bulk of sucker biomass in the reservoirs since they are, at
present, more abundant than white suckers in the river and in the north as a
whole.
Spring drawdowns may impair production of longnose suckers in the reservoirs.
Longnose suckers in Labrador spawn usually in June (W. Bruce, pers. comm.) in
streams or shallow lake areas. Drawdowns from that time until about a month
later when fry move to deeper waters may cause mortalities.
WHITE SUCKER
CATCHES
Overall, 689 gillnets fished overnight caught 711 white suckers with a
total weight of 353.4 kg (Fig. 28). Giving equal weight to each mesh size, a
single net night averaged 1.0 fish weighing 0.51 kg. Captured fish had a mean
length of 32.2 em, a mean we i ght of 0.50 kg, and a mean age of 7.5 years.
Fig. 28. White sucker.
40
Catches per net night in different river sections varied from 0.11 kg in
Section III to 1.06 kg in Section IV (Fig. 29). Yields tended to be greater
upstream of Gull Island.
[]
:::[lt[}, O·l~ . · , ;
O·Z , ,
01 ' r::L
O O SECTIOH SECTION • SECTION SECTION SECTION
I II lll II/ V
GROWTH IN LENGTH
Fig. 29. Catches of white suckers
in five sections of the Lower
Churchill River, June-August, 1975-76.
The ages of white suckers age 5 and over are usually underestimated from
scales (Beamish arid Harvey 1969). As a result, the obtained age-length relationships
(Fig. 30 and Appendix V) may portray a faster rate of growth than actually
occurs. Overall the rate of growth was close to the middle of the range previously
described for white suckers (Beamish 1973) and slightly lower than the rate of
growth in Ten Mile Lake, Labrador (Parsons 1975).
48
46
44
42
40
lB
l&
34
32
41
•-• SECTION I
•----·• SECTION II
11-11 SECTION Ill
0----o SECTION IV x-• SECTION V
O 0 I z 3 4 5 6 7 a 9 10 II 12 13 14 15 16 17 18
AGE !YEARSi
Fig. 30. Growth of white suckers in the
Lower Churchill River, -1975-76 .•
Presented for contrast is the total
range in growth (solid heavy lines) of
white suckers over the zoogeographic
range (Beamish 1973).
Within the river, growth was most rapid in Section III downstream of
Winokapau Lake and slowest in Section I downstream of Muskrat Falls. Little
variation was evident in the remaining three sections.
The inqximum age of white suckers in the Lower Churchill River, 18 years,
was similar to theusual maximum age of this species obtained from scales
(Scott and Crossman 1973).
GROWTH IN WEIGHT
Exponents in the length-weight relationship of white suckers from the Lower
Churchill River ranged from 3.13 to 3.60 and had a mean of 3.30 (Table 14)~
higher than the values of 2.4-2.5 observed in other areas of Labrador (W. Bruce,
pers. comm.).
42
Table 14. Least squares linear regressions of log 10 weight (g) on
log 10 fork length (em) for white suckers from the Lower
Churchill River, June-August 1975-76.
River y Correlation No. of
section intercept Slope coefficient fish
I -2.16 3. 18 0.974 199
II -2.19 3.23 0.996 171
III -2.79 3.60 0.982 20
IV -2.09 3.13 0.995 113
v -5.46 3.37 0.987 150
Means -2.94 3.30
SEX RATIOS AND MATURITY
The overall sex ratio (males per female) of white suckers in the river
indicated an equal abundance of the sexes (Appendix VI). _Ratios were 0.86-
1.22 with an overall ratio of 1.01.
Of 550 white suckers examined, 76.4% were 'mature (Appendix VII). On the
average, white suckers matured at about 22 em; the length attained by fish in
their fifth to sixth year of life. The age at maturity over the range varies
from 3 to 8 years (Scott and Crossman 1973).
FOOD
White suckers from the Lower Churchill River fed primarily on benthic
invertebrates (Table 15), the usual f6od of this species (Scott and Crossman
1973).
43
Table 15. Percentage occurrence of major food items in the stomachs of
white suckers in the Lower Churchill River, June-August 1975-76.
River section
Food item I II III IV v I-V combined
Detritus 62.7 77.3 100.0 80.3 86.1 77.6
Diptera (larvae) 42.7 74.7 86.7 76.4 49.8
Insect remains 76.0 65.3 6.7 28.9 23.6. 49.5
Diptera (pupae) 24.0 34.7 13.3 25.0 55.6 33.5
Hirundinea 25.3 21.3 26.7 14.4 27.8 22.4
Mollusca 26.7 29.5 52.8 23.0
Trichoptera 24.0 30.3 8.3 15.0
Invertebrate eggs 16.0 10.6 6.6 5.6 9.3
Copepoda 25.0 6.0
Plecoptera 14.7 1.3 6.9 5.4
Coleptera 17. 1 4.2
Ephemeroptera lQ. 5 2.6
Hydracarina 5.3 11.1 3.8
Ceratopogonidae 3.9 1.0
C1adocera 3 .. 9 1. 0
Amphipoda 2.6 0.6
Hymenoptera 2.8 0.6
Arachnida 1.4 0.3
Number of stomachs
examined 75 75 15 76 72 313
Number of stomachs
empty 8 5 0 0 10 23
SELECTION BY GEAR
Mean lengths, weights, and ages of captured white suckers tended to be
greater with greater mesh size in the river as a whole (Fig. 31 and 32, Table 16)
and in the individual river sections (Appendices VIII and IX).
The most efficient, in terms of weight, was the 10.2 em mesh size. This
mesh captured 1.3 fish weighing 1.28 kg/net night. All fish captured in the
10.2 em mesh were age 7 and over and 30 em or larger.
20
=
44
150r--,...--,...--,.----r---r---r-----,
100 Hem MESH
N • 51 so
0~-~~====~---------~
150
100
Hem MESH
N • 102
50 '\
0~--~~~~~~------~
200
150
7·6 em MESH
N • 163
;;: 100
~ 50
~ 0~---~CC~~~~~~---~ .. i 100 10·2 em MESH
N • 132
50 /
0~------~~~~~-----~
100
50
200
150
100
tHem MESH
N • 5
H-12-7 em MESH
N • 453
/
50 /3
0~-~~~~~~~~~--~-~
0 10 20 30 40 50 60 TO
INTERVALS OF FORK LENGTH (cntl
Hem MESH
N • 48
5•1 em MESH
N • 100
10
o~-L~~~~~L-----------------
so
40
30
7-6 em MESH
N • 143
10
0~------~~~~~~~~~~~~
10
60
50
40
30
20
Ji
3-8-INem MESH
N • 419
3 4 5 6 7 8 9 10 II 12 13 14 15 16 17 1B
AGE GROUP \YEARS!
Fig. 31. Length-frequency distribution
by gillnet mesh size of white suckers
from the Lower Churchill River above
Muskrat Falls, June-August, 1975-76
Fig. 32. Age-frequency distribution by
gillnet mesh size of white suckers from
the Lower Churchill River above Muskrat
Falls, June-August, 1975-76.
45
Table 16. Catch statistics of white suckers from Sections II-V of the Lower
Churchill River, June-August 1975-76.
Weight
Mesh No. of No. of No. of Mean Total r~ean per net Mean
size net fish fish per length weight weight night age
(em) nights caught net night (em) (kg) (kg) (kg) (yr)
3.8 107 51 0.5 19.4 5.8 0.11 0.05 4.2
5. 1 107 102 0.9 26.4 23.7 0.23 0.22 5.9
7.6 109 163 1.5 36.1 112.7 0.69 1.03 8.5
10.2 109 138 1.3 41.6 139.5 1. 01 1.28 11.3
12.7 107 5 <0. 1 47.9 6.8 1.36 0.06 15.0
MORTALITY RATE
The total instqntaneous mortality rate of white suckers (Fig~ 33) at M ::.;_Q-~56
was nearly identical to that of longnose suckers and may have been overestimated
as a result of age underestimation.
4-6 ...--.~-.---.-..,..-.,--.,.--..-..,...-,--.--,--,..--,--,..--,---,---,
4·4
H
4·0
3-8
H
H
H
3·0
z.s
z 2·4
~ 2·2
2·0
1·8
1·6
1·4
1·2
1·0
0·8
0·6
0·4
a.2
M • 0·56
A • 0•43
r • 0·92
AGES 12-15
0·0 L--J.-..L.._J.__L.._t__.L__jL-..L---L_J._...J.._..L_J.........!--1..___._--"---l
0 I 2 3 4 5 6 7 8 9 10 II 12 13 14 15 16 17 18
AGE GROUP IYEARSI
Fig. 33. Catch curve of white suckers
from the Lower Churcnill River above
Muskrat Falls, June-August, 1975•76.
46
DISCUSSION
The white sucker is an adaptable fish widespread throughout Canadian
waters. These facts and its present levels of abundance in the Lower Churchill
River suggest that white suckers will be abundant in the new reservoirs.
It is not expected that growth rates will change significantly in the
long term after construction of the reservoirs. The likely similarity of
chemical and physical conditions below the site of the Muskrat Falls dam
suggests that white sucker growth will remain similar in this area. The lack
of a marked variation in the growth of younger fish above the dam site at
present, in spite of varied habitats, suggests that growth wi~l not change
markedly in the future.
White sucker production should increase after impoundment with the
usual increase in benthic food organisms. This is also indicated by the
greatest catches being obtained from Winokapau Lake, that part of the river
system most resembling the reservoirs.
Fluctuating water levels in the spring may prevent white suckers from
attaining their potential production. White suckers usually spawn in June in
Labrador in or near streams or on lake margins in shallow water (W. Bruce, pers.
comm.). Drawdowns from that time until about a month later when the fry move to
deeper water will likely be deleterious.
BROOK TROUT
CATCHES
Overall, 689 gillnet nights of fishing yielded 579 brook trout weighing
261.6 kg; corresponding to a catch per unit effort of 0.8 fish weighing 0.38 kg/net
night (Fig. 34). Captured trout had a mean length of 30.6 em, a mean weight of
0.45 kg, and a mean age of 3.7 years.
Catches were highly variable within the river. In terms of numbers and
weight, catch per unit effort was highest in Section III and lowest in Section II
(Fig. 35). Catches were greater above the dam site at Gull Island than they
were below and greatest in the two fastest-flowing river sections, III and V.
GROWTH IN LENGTH
Brook trout growth in the Lower Churchill River was nearly linear (Fig. 36,
and Appendix V). On the whole, growth in length was more rapid than that on the
Avalon Peninsula of Newfoundland (Whelan and Wiseman 1977) but slower than that
in Ten Mile Lake, Labrador (Parsons 1975), the Smallwood Reservoir (Bruce
1974), and Lake Anne Marie, Labrador (Flick 1977).
1·0
1·8
1·6
1·4
~1-2
~ 1·0
0·8
0·6
0·4
0·1
0·0
SECTIO N
II
47
Fig. 34. Brook trout.
Fig. 35. Catches of brook trout in
five sections of the Lower Churchill
River, June-August, 1975-76.
48
46
6
_f
34
/'f/' 32
30
28
]zs
"' :;· \'; 24 / /, . z ~ 22 .. /l/' ~ 20 ...
18
16
14 /) . 12 1t •-• SECTION I
10 o----o SECTION Ill
6-A SECTION V
A
00 3 4
AGE (YEARS I
Fig. 36. Growth of brook trout in the Lower Churchill
River, 1975-76. Solid heavy lines approximate the
greatest (Flick 1977) and lowest (Whelan and Wiseman 1977)
rates of growth re~orted for Newfoundland and Labrador.
49
Within the river, grov1th was most rapid in the fast waters of Section III
downstream of Winokapau Lake and slowest in Section I below Muskrat Falls.
The longevity of brook trout from the Lower Churchill, 6 years, was within
the 5-8 years usually observed in wild brook trout populations (Scott and Crossman
1973).
GROWTH IN WEIGHT
Exponents in the length-weight relationships of brook trout ranged from
2.69 to 3.23 and had a mean of 2.99 (Table 17); lower than the 3.2-3.3 reported
for other Labrador populations (Bruce 1974; Parsons 1975).
Table 17. Least squares linear regressions of·log 10 weight (g) on
1og 10 fork length (em) for brook trout from the Lower
Churchill River, June-August 1975-76.
River y Correlation No. of
section intercept Slope coefficient fish
I -1.57 2.69 0.964 35
III .;.2.04 3.06 0.987 183 v ~5.28 3.23 0.990 87
Means -2.96 2.99
50
SEX RATIOS AND MATURITY
The overall sex ratio indicated an equal abundance of the sexes. Numbers
of males per female in the five sections were 0.67-2.00 with an overall
ratio of 1.07 (Appendix VI).
Of 695 brook trout examined, 91.9% were mature (Appendix VII). The smallest
length interval in which more than 50% of the individuals were mature was 16.0-
17.9 em; having 63.0% mature fish. This length interval corresponded to the
length attained by fish in''their third to fourth year of life; the usual age of
brook trout at maturity (Scott and Crossman 1973). There were a few immature
individuals in most length intervals up to 46 em.
FOOD
Brook trout from the Lower Churchill River fed primarily on benthic invertebrates
the usual food of medium-size trout (Scott and Crossman 1973). Fish also comprised
a part of the diet (Table 18).
Table 18. Percentage occurrence of major food items in the stomachs of
brook trout in the Lower Churchill River, June-August 1975-76.
River Section
Food item I II III IV v I-V combined
Insect remains 61.8 42.7 75.0 48.6 46.4
Plecoptera 23.5 56.0 25.0 35.7 39.2
Diptera (pupae) 84.0 12.9 37.1
Detritus 56.0 50.0 38.6 36.6
Coleoptera 38.2 50.0 34.7 50.0 25.7 30.9
Fish remains 41.2 14.7 22.9 21.1
Trichoptera 24.0 75.0 21.4 18.6
Hymenoptera 14.7 16.0 50.0 20.0 17.0
Ephemeroptera 4.0 15.7 7.2
Odonata 1.3 18.6 7.2
Diptera (larvae) 17.7 4.0 25.0 5.2
Diptera (adult) 14.3 5.2
Arachnida 2.7 50.0 2.9 3.1
Gasterosteus aauLeatus 25.0 5.7 2.6
Invertebrate eggs 2.7 2.9 2.1
Hemiptera 5.7 2.1
Lota 1.ota 5.7 2.1
Cladocera 4.3 1.6
Lepidoptera 4.3 1.6
Catostomus s p. 1.3 0.5
Fish eggs 1.3 0.5
Homoptera 25.0 0.5
Orthoptera 1.4 0.5
Cottus sp. 1.4 0.5
-Number of stomachs
examined 34 2 75 4 79 194
Number of stomachs
empty 1 0 0 9 11
51
SELECTION BY GEAR
Overall, mean lengths, weights, and ages tended to increase with increasing
mesh size; but these trends were not very strong (Fig. 37 and 38, Table 19). These
trends were less pronounced within the individual river sections (Appendices
VIII and IX). The most efficient mesh size, 7.6 em, captured 2.5 fish weighing
1.31 kg/net night. Ninety-eight percent of the trout taken in this mesh size
were age 3 and over and 93% were 30 em or larger.
Table 19. Catch statistics of brook trout from Sections II-V of the Lower
Lower Churchill River, June-August 1975-76.
Weight
Mesh No. of No. of No. of Mean Total Mean per net Mean
size net fish fish per length weight weight Dight age
(em) nights caught net night (em) (kg) (kg) (kg) (yr)
3.8 107 84 0.8 20.8 10.5 0.13 0.09 2.4
5.1 107 87 0.8 27.6 22.6 0.26 0. 21 3.1
7.6 109 270 2.5 35.0 142.6 0.53 1. 31 3.9
10.2 109 93 0.9 40.2 75.3 0.8·1 0.69 3.9
12.7 107 7 o. 1 37.0 5.6 0.80 0.05 4.1
MORTJl.LITY RATE
The mortality rate of brook trout from the Lower Churchill River, M = 1.18
(Fig. 39), was slightly lower than the value of 1.21 from Jacopie Lake, Smallwood
Reservoir, ~nt:l the va)ue Of 1.49 from Valley River, Labrador (W. Bruce, pers. comm.).
DISCUSSION
There are indications that the growth rate and production of brook trout
in the Lower Churchill River will decrease after the river is impounded. The
more rapid growth in length and weight and the greater catches of trout from
the faster-flowing river sections suggest that, after impoundment, growth rates
and production will decrease in these sections.
It is possible that much of the variation in the catch from section
to section is attr·ibutable to migrations of the trout to preferred locations.
Usually, however, brook trout tend to move from streams and rivers to larger
bodies of water when temperatures rise.
It is likely that the reproductive success of brook trout will decrease
after the impoundment of the river. At the present time, brook trout probably
utilize the river itself as well as its tribL•taries for spawning. Slower
80r--;.-----,---,---,---,---.----,
60
40
20
60
40
Hem MESH
N: 84
\
5·1 em MESH
N • 87
ro 1\
0~----~~~~~------~~
300
2~0
7·6 em MESH
N • 270
~200
.: 150
~
"'100 ...
~ 50
i
60
40
ro 1\
0~----~~~~~----~
300
250
200
150
100
3·8 ~12-1 em MESH
N • 541
~ \
0~-~~~~~~~~~~~~
0 I 0 20 30 40 50 60 70
INTERVAlS OF FORK lENGTH (em)
40 r--.--r---r---r---r--;--,
30
20
Hem MESH
N • 55
10
o~==~~~~~===--~-~
90
80
TO
60
50
40
30
20
10
3 4
AGE GROUP (YEARS)
5·1 em MESH
N: 51
52
Fig. 37. Length-frequency distribution by
gillnet mesh'size of brook trout from the
Lower Churchill River above Muskrat Falls,
June-August, 1975-76.
Fig. 38. Age-frequency distribution by
gillnet mesh size of brook trout from the
Lower Churchill River above Muskrat Falls,
June-August, 1975-76.
...
ll
H
H
l 0
Z2
20
II
,.,
14
1·0
M: 118
A :0 69
t : 0·9~
AGES 3-6
0 0 '---1.--1--'---'-..L..-..J--'----'
o ' 2 1 • 5 & 1 a
AGE GROUP IY!JRSI
53
Fig. 39. Catch curve of brook trout
from the Lower Churchill River above
Muskrat Falls, June-August, 1975-76.
water velocities in these favorable locations and drawdown from fall spawning
until fry emergence in spring will probably be detrimental. In addition,
increased sediment loads on spawning beds and greater water depths over present
spawning areas may be harmful.
BURBOT
CATCHES
Overall, 689 gillnet nights of fishing yielded 85 burbot weighing 59.9 kg
or 0.1 fish weighing 0.09 kg/net night (Fig. 40). Captured burbot had a mean length
of 44.6 em, a mean weight of 0.70 kg and a mean age of 7.4 years.
Catches varied from 0.03 kg net/night in Section I to 0.30 kg/net night
in Section IV (Fig. 41). Catches tended to be greater above the site of the
Gull Island dam than below and, with one exception, greater with greater
distance upstream.
o-•
0·2
0·1 n
0 0 I t. I . ,~1
~ 0·3
0·2
0·1
on
54
Fig. 40. Burbot.
n
t , '
Fig. 41. Catches of burbot in five
sections of the Lower Churchill River,
June-August, 1975-76.
O·O L...J':-::-::::::-'--'-:=:-:-'-----':-:SE:::CT710 N.l_'-;S:::EC:O::TIO:::'N ----"':::SEC~TI=ON'--___j
Ill I V V
55
GROWTH IN LENGTH
The growth of burbot from the Lower Churchill River (Fig. 42 and Appendix V)
tended to be midway between the extremes reported for Canadian waters (McCrimmon
and Devitt 1954; Beamish et al. 1976).
Within the river, mean lengths of the age groups tended to be the least
in Section V and greatest in Section III. Sample sizes were, however, small
in all sections and negated the back-calculation of growth.
The age of the oldest burbot, 14 years, was within the probable maximum
age in Canada of 10-15 years (Scott and Crossman 1973).
BO ,-,-.,.-,..-,--,-,-,-,--r--;-,..-,---;-,---.,--,
75
70
65
60
55
25
20
15
10
X
c. a 111
c. c. a
• a X X
0
·y~:~ c.
V' i • ' • SECTION I
• SECTION II
t. SECTION Ill a SECTION IV
X SECTION V
0~~-L-L~~~~~~-L~~~
0 I 2 3 4 5 E 7 S 9 10 II 12 13 14 15 16
AGE GROUP (YEARS)
GROWTH IN WEIGHT
Fig. 42. Growtb of burbot in the
Lower Churchill River, June-August, 1975-76.
Solid heavy lines approximate the
greatest (Mctrimin6n and Devitt 1954)
and lowest (Beamish et al. 1976) rates
of growth in Canada.
Length-weight relationships of burbot from the Lower Churchill had exponents
of 3.14-3.28 with a mean of 3.19 (Table 20).
56
Table 20. Least squares linear regressions of log 10 weight (g) on
log 10 total length (em) for burbot from tne Lower Churchill
River, June-August 1975-76.
River y Correlation No. of
section intercept Slope coefficient fish
III -2.44 3.14 0.989 18
IV -2.69 3.28 0.988 23
v -5.42 3.14 0.998 24
Means -3.52 3.19
SEX RATIOS AND MATURITY
The overall sex ratio of the 84 burbot examined, 0.68, did not indicate
a differential abundance of the sexes. Within river sections, the number of
males per female ranged from 0.18 to 5.00 (Appendix VI).
Of 79 burbot examined, 86.1% were mature (Appendix 'III). On the average,
burbot were mature at a length of about 33 em; corresponding to fish in their
fifth year of life. This is similar to the usual attainment of maturity in
the third or fourth year at lengths of 28-48 em (Scott and Crossman 1973).
FOOD
Burbot from the Lower Churchill River fed on fish and aquatic invertebrates
(Table 21) as is usual for this species (Scott and Crossman 1973).
SELECTION BY GEAR
Mean lengths, weights, and ages of captured burbot tended to increase
with increasing mesh size when the data were combined (Fig. 43 and 44, Table 22)
and in the individual river sections (Appendices VIII and IX). The most
efficient mesh size in terms of weight was the 10.2 em; catching 0.2 fish
weighing 0.22 kg/net night. Ninety-five percent of burbot taken in this mesh
size were 40 em or larger and 93% were age 9 or over.
57
Table 21. Percentage occurrence of major food items in the stomachs of
burbot in the Lower Churchill River, June-August 1975-76.
River section
Food item I II III IV v I-V combined
Fish remains 85.7 30.8 20.0 15.4 41.7
Insect remains 57.1 53.9 80.0 11.5
Detritus 30.8 50.0 19.2
, Pl ecoptera 57·.1 11.5 25.0·
Trichoptera 40.0 33.3
Lota Zota 7.7 3.8 25.0
Gasterosteus
aauZeatus 57.1 7.7
Diptera (pupae} 23.1 20.0 3.8
Diptera (larvae} 28.6 7.7 3.8
Invertebrate eggs 10.0 3.8
Ephemeroptera 20.0
Coregonus aZupeaformis 10.0
Cottus sp. 10.0
Couesuis p Zumbius 3.8
Catostomus sp. 3.8
Odonata 3.8
Number of stomachs
examined 7 13 10 26 24
Number of stomachs
empty 0 2 0 12 10
Table 22. Catch statistics of burbot from Sections II-V of the Lower
Churchill River, June-August 1975-76.
Weight
32.5
27.5
17.5
16.3
15.0
10.0
7.5
7.5
5.0
2.5
2.5
1.3
1.3
1. 3
1.3
1.3
80
24
Mesh No. of No. of No. of Mean Total Mean per net
size net fish fish per length weight weight night
(em} nights caught net night (em} (kg) ! (kg) (kg)
3.8 107 2 <0. 1 22.5 0.1 0.05 <0.01
5.1 107 13 0. 1 ~0.9 2.3 0.18 0.02
7.6 109 33 0.3 44.1 17.6 0.53 0.16
10.2 109 22 0.2 53.3 23.5 1.07 0.22
12.7 107 8 o. 1 55.1 12. 1 1.51 0.11
Mean
age
(yr)
3.0
5.1
7.2
9.9
9.4
10
0
10
2~
20
I~
10
= "' ;::: 0
.... o I~
"' ::1!: 10
I s
0
0
30
2~
20
I~
10
12-7 em MESH
N • 8
H-INem MESH
N • 78
5·1 em MESH
N • 13
Hem MESH
N • 33
Hem MESH
N • 2
o~---~L---------------------------------------1 10 5·1 em MESH
N • 13
7-6 em MESH
N • 32
10·2 em MESH
N • 15
58
Fig. 43. Length-frequency distribution
by gillnet mesh size of burbot from the
Lower Churchi 11 River above ~1uskrat
Falls, June-August, 1975-76
Fig. 44. Age-frequency distribution by
gillnet mesh size of burbot from the
Lower Churchill River above Muskrat
Falls~ June-August, 1975-76.
59
MORTALITY RATE
The instantaneous mortality rate of burbot above Muskrat Falls was 0.72
(Fig. 45); slightly lower than the value of M =1.00 for burbot from Heming Lake,
Manitoba (calculated from data of Lawler 1963).
z: ..
"' 0 ....
2·6
24
2·2
2·0
1·8
1·6
1·2
•
•
M:. 0·72
A= 0·51
r = 0·91
AGES 11-14
•
•
•
0·0 ._.__....__...__.....__.___._......__.__...._,.......___.___,.,__....
2 3 4 5 6 7 8 9 10 II 12 13 14 15
AGE GROUP {YEARS)
DISCUSSION
Fig. 45. Catch curve of burbot from the Lower Churchill
River above Muskrat Falls,
June-August, 1975-76.
Data collected to date suggest that burbot production in the Lower Churchill
River will increase after the river is impounded. The fact that the greatest
length-weight exponent and the greatest catch were observed in Winokapau Lake
suggest that, as the river becomes more of a lake-like environment, burbot production
in the river will approach that of Winokapau Lke.
Increases in burbot production will be assisted if the usual increase in
benthic invertebrates occurs after impoundment. Burbot production may be impaired
by excessive drawdown. Burbot usually spawn under the ice from January to March
in Canada at depths of about 0.3-3.0 metres and the young usually anoear from late
February to June (Scott and Crossman 1973). Drawdmms over this p·eriod will kill the
eggs.
60
LAKE TROUT
CATCHES
Lake trout (Fig. 46) were captured only in three sections upstream of Gull Island •
(Fig. 47). Overall, 689 gillnet nights of fishing yielded 15 lake trout weighing
51 .8 kg. Captured trout had a mean length of 57 .0 em, a mean weight of 3.45 kg,
and a mean age of 10.3 years.
Catches were greatest in Winokapau Lake (Section IV).
Fig. 46. Lake trout.
Fig. 47. Catches of lake trout in
three sections of the Lower Churchill
River, June-August, 1975-76.
0·2
5£('!'10~ SECT ION
I H I Y
61
GROWTH IN LENGTH
The small sample of lake trout prevented back-calculation of growth.
However, the mean lengths of the fish in each age group indicated an overall
rate of growth similar to that in the Smallwood Reservoir (Bruce 1974, 1975)
(Fig. 48 and Appendix V) and within the extremes reported over the zoogeographic
range (Healey 1978).
100
95
90
85
80
75
70
65 0 0 0 0
"i 60
~
:: 55 0 ...
j "' ~50 6 ....
"'45
! 40 I
35 l
30 l
25 6 SECTION Ill 1
0 SECTION IV I
20 x SECTION V l 15
10
O 0 I 2 3 4 5 6 7 8 9 10 II 12 13 14 15 16
AGE GROUP (YEARS)
Fig. 48. Growth of lake trout in the
Lower Churchill River, June-August, 1975-76.
The solid heavy lines approximate the
variation in growth over the zoogeographic
range (Healey 1978).
No marked variation in growth within the river was apparent, possibly due
to th.e. sma 11 samp 1 e size.
The maximum age of lake trout captured, 15 years, was similar to that
recorded in Labrador by Bruce (1974, 1975) and Parsons (1975) but less than the
20-25 years of the largest North American lake trout (Scott and Crossman 1973).
GROWTH IN WEIGHT
Sample sizes were too small for computation of length-weight relationships.
Exponents in the length-weight relationships of Labrador lake trout generally
have ranged from 2.9 (Bruce 1974, 1975) to 3.2 (Par~ons 1975).
62
SEX RATIOS AND MATURITY
Numbers of males per female in the three sections of river ranged from
0.50 to 3.00 (Appendix VI). The overall ratio, 0.88, did not indicate a differential
abundance of the sexes.
Of 15 lake trout examined, only one was immature (Appendix VII). The small
sample suggested that, on the average, maturity was achieved at a length of
about 35 em; a length corresponding to fish in their seventh year. Sexual
maturity is usually attained at age 6 or 7 (Scott and Crossman 1973).
FOOD
Fishes, followed by insects, were the principal food items in the stomachs
of captured lake trout (Table 23).
Table 23. Percentage occurrence of major food items in the stomachs of
lake trout in the Lower Churchill River, June-August 1975-76.
River .. section
Food item III IV v I-V combined
Fish remains 100.0 100.0 55.6
Gaste~osteus acuZeatus 50.0 22.2
Insect remains 50.0 22.2
Setritus 50.00 22.2
Co~egonus cZupeaformis 25.0 11.1
Number of stomachs
examined 1 4 4 9
Number of stomachs
empty 0 0 0 0
SELECTION BY GEAR
Captured lake trout were all between 30 and 100 em (Fig. 49). The small
sample was irregularly distributed with respect to age (Fig. 50). No consistent
variation in length, weight, or age with mesh size was evident in the river as
a whole (Table 24) or in the individual river sections (Appendices VIII and IX).
The most efficient mesh size, in terms of weight and numbers, was the
10.2 em; yielding 0.1 fish weighing 0.21 kg/net night.
.. I
..
63
E ~ E ~ ro ~ ~
INTERVALS OF. FQ_RK LENGTH (em I
N =15
5 6 7 8 9 10 II 12 13 14 15 16
AGE GROUP (YEARS)
Fig. 49. Length-frequency distribution
of gillnetted lake tro1,1t from the
Lower Chur~hill River above the site
of the proposed Gull Island dam,
June-August, 1975-76.
Fig. SO. Age-frequency distribution
of gillnetted lake trout from the
Lower Churchill River above the site
of the proposed Gull Island dam,
June-August, 1975-76.
Table 24. Catch statistics of lake trout from Sections III-V of the Lower
Churchill River, June-August 1975-76.
Weight
Mesh No. of No. of No. of Mean Total Mean per n'et Mean
size net fish fish per length weight wejght night age
(em) nights caught net night (em) (kg) (kg) (kg) (yr)
3.8 107 1 <0.1 92.0 10.4 10.40 0.09 15.0
5.1 107 1 <0. 1 37.4 0.8 a.8a a.al 7.a
7.6 109 1 <a. 1 56.5 2.1 2.13 a.a2 1l.a
1 a. 2 109 9 a. 1 54.2 22.8 2,53 a. 21 la.5
12.7 la7 3 <a. 1 69.3 15.7 5.23 0.15 12.7
64
MORTALITY RATE
The natural mortality rate (M = 0.41) of Lower Churchill River lake trout
(Fig. 51), obtained from very few data, was higher than the 0.20~0.30 instantaneous
rate typical of unexploited populations (Healey 1978), but lower than the 0.55
instantaneous rate of unexploited Smallwood Reservoir fish aged by scales
(W. Bruce, pers. commm.).
1·4
1·2 M= 0·41 \ f-A=0·34
r = 1·00 • \ 1·0 AGES 14-15
z 0·8 Fig. 51. Catch curve of lake trout .. • • from the Lower Churchill River above the "' \ ~Q-6 site of the proposed Gull Island dam,
June-August, 1975-76.
0·4
0·2
0·0 5 6 7 8 9 10 II 12 13 14 15 16
AGE GROUP (YEARS)
DISCUSSION
There is some indication that lake trout production in the Lower Churchill
River will improve after impoundment. In his literature review, Machniak (1975c),
has concluded that lake trout in reservoirs may do well if flooding doesn't
upset predator-prey relationships and spawning.
As previously discussed, whitefish, suckers and benthic invertebrates can
be expect~d to be abundant in t.he ~eservoirs. These should provide adequate
forage for lake trout.
The comparative relative abundance of lak.e trout above the site of the Gull
Island dam as compared to below and the greatest catch in Winokapau Lake also
suggest that, as the river is impounded, trout production will increase.
The absence of lake trout in catches obtained from the site of the Muskrat
Falls Reservoir suggests that, if available habitat in that reservoir is to be
fully used, lake trout must be introduced after construction is finished. In
the following discussion it is assumed that this will be done.
Drawdowns may be detrimental to lake trout production in the reservoirs.
Machniak (1975c) has reported that water level fluctuations may be overcome by
~hanges in spawning locations. However, there is a period of about 5 months or
more in Labrador when eggs, especially those on shallow bars and reefs, are
65
liable to die during drawdown. In Maine, the policy has been to suggest that no
drawdowns should occur between September 15 and late April to ensure that the
loss of lake trout spawn is minimized.
Siltation of spawning areas in the reservoirs is likely to be harmful to
lake trout. Once created, the reservoir will act as a settlina basin for silt,
thus impairing egg and fry survival. -
OUANANICHE (LANDLOCKED SALMON)
CATCHES
Overall, 689 gillnet nights of fishing yielded 30 ouananiche weighing
35.3 kg (Fig. 52). Captured fish had a mean length of 41.7 em, a mean weight of
l .18 kg and a mean age of 6.2 years.
Fig. 52. Ouananiche.
No ouananiche were caught downstream of the site of the Gull Island dam
(Fig. 53). Upstream of the dam site, catches were highest in Winokapau Lake
(Section IV) and lowest in Section III just above the site of the Gull Island
dam.
GROWTH IN LENGTH
The rate of growth of landlocked salmon in Section IV of the Lower Churchill
River (Fig. 54 and Appendix V) was similar to the maximum previously reported
for Newfoundland and Labrador (Bruce 1974). The large calculated lengths at
younger ages were most likely artifacts of the small sample size. Little variation
in growth rates was apparent within the river, likely as a result of the small
66
s
AGE IYEARSI
Fig. 53. Catches of ouananiche in three
sectionsof the Lower Churchill River,
June-August, 1975-76.
Fig. 54. Growth of ouananiche in Section
IV of the Lower Churchill River, 1976.
Solid heavy lines approximate previously
reported minimum (Bruce 1976) and maximum
(Bruce 1974) rates of growth in
Newfoundland ~nd Labrador.
"
67
samples obtained from Sections III and V {Appendix V). The small amounts of
data from these sections prevented back-calculation.
The maximum age of landlocked salmon from the Lower Churchill River,
9 years, was usual for eastern Canadian salmon (Scott and Crossman l9l3) but
less than the 14 years reported by Pippy (1966) for Long Lake, Newfoundland.
GROWTH IN WEIGHT
The mean length-weight exponent of Lower Churchill o.uananiche (Table 25)
was nearly indentical to the 3.18 of ouananiche from Red Indian Lake, Newfoundland
(Marry and Cole 1977) 'but greater than the 2.62 of fish from· Thomas Pond Reservoir,
Newfoundland (Wiseman 1971).
Table 25. Least squares linear regressions of log 10 weight {g) on
log 10 fork length (em) for ouananiche from the Lower
Churchill River, June-August 1975-76.
River y Correlation No. of
section intercept Slope coefficient fish
IV -4.67 2.82 0,984 22 22 v -5.81 3.56 0.957 11
Means -5.24 3.19
SEX RATIOS AND MATURITY
The overall sex ratio of ouananiche, 0.90 {Appendix VI), did not indicate
a differential abundance of the sexes.
Of 35 ouananiche examined, 82.9% were mature (Appendix VII)~ No length at
maturity was evident in the small sample. Age at maturity of Newfoundland
landlocked salmon has been reported at 2-3 years of age (Leggett and Power 1969).
FOOD
Ouananiche from the Lower Churchill were primarily piscivorous (Table 26).
This likely produced their comparatively rapid growth in length and weight.
68
Table 26. Percentage occurrence of major food items in the stomachs of
ouananiche in the Lower Churchill River, June-August 1975-76.
River section
Food item III IV v III-V <;ombined
Gasterost~uc aauZeatus 72.2 40.6
Fish remains 22.2 54.5 28.1
Plecoptera 66.7 27.8 21.9
Detritus 33.3 18.8
Hymenoptera 27.8 15.6
Insect remains 66.7 16.7 15.6
Trichoptera 1-00.0 5.6 12.5
Catostomus s p. 36.4 12.5
Invertebrate eggs 66.7 5.6 9.4
Coregonus aZupeafo~is and
Prosopium ayZindraaeum 27.3 9.4
Diptera (larvae) 16.7 9.4
Hemiptera 11.1 6.3
Ephemeroptera 5.6 3.1
Diptera (pupae) 5.6 3. 1
Eso:x: Zuaiu.s · 5.6 3.1
Coleoptera 33.3 3.1
Number of stomachs examined 3 18 11 32
Number of stomachs empty 0 1 1 2
SELECTION BY GEAR
All ouananiche captured were between 10 and 70 em with 83% being 40 em
or greater (Fig. 55). Ages ranged from 3 to 9 years with 93% being 5 and over
(Fig. 56). There were no consistent relationships between length, weight, or
age and mesh size in the river as a whole (Table 27) or in the individual
river sections (Appendices VIII and IX). This was probably due to the small
sample size.
IS
I
16 f-
I
!4~
!ilJ<L
;10~
f5 a~ ~ i ~ 6 ~ + n-
N • '30
10 zo 30 40 so so ·c
INTERVALS OF FORK LENGTH leml
Fig. 55. Length-frequency distribution
of gillnetted ouananiche from the Lower
Churchill River, above the site of the
proposed Gull Island dam, June-August,
1975-76.
..
•
10
:::
~ 8 ...
~ 6 ..... ...
~ 4 :z
2
69
Fig. 56. Age-frequency distribution of
gillnetted ouananiche from the Lower
Churchill River above the site of the
proposed Gull Island dam, June-August,
1975-76 .
3 4 5 6 7 8 9 10
AGE GROUP (YEARS!
Table 27. Catch statistics of ouananiche from Sections IIl-V of the Lower
Churchill River, June-August 1975-76.
Weight
Mesh No. of No. of No. of Mean Total Mean per net r~ean
size net fish fish per length weight weigh.t night age
(em) nights caught net night (em) (kg) (kg), (kg) (yr)
3.8 107 9 o. 1 44.9 9.6 1.1 0.09 6.0
5.1 107 7 0. 1 43.4 8.1 1.2 0.08 6.0
7.6 109 4 <0. 1 44.8 4.5 1.1 0.04 6.5
10.2 109 8 o. 1 45.4 9.9 1.2 0.09 6.8
12.7 107 2 <0. 1 50.7 3!0 1.5 0.03 8.0
The most efficient mesh sizes were the 3.8 and 10.2 em; each yielding
0.1 fish weighing 0.09 kg/net night.
MORTALITY RATE
The annual mortality rate (A) of ouananiche from the Lower Churchill
River was 0.68 (Fig. 57). Although based on few data, the estimate was similar
to the approximate 0.60 annual rate in Gamba Pond, Newfoundland (calculated
from data of Leggett and Power 1969) and the 0.62 annual statewide average
in Maine (Havey and Warner 1970).
-DISCUSSION
The greater catches of ouananiche from the lake portion as opposed to
the river portions, of the Lower Churchill, their comparatively rapid growth
in length and weight in Winokapau Lake, and their utilization of a variety
70
2·8
2·4
•
2•0
:z: 1·6 ..
"" 3 1·4
1·2
1·0 M: 1-15
A : 0·68
0·8 r = 0·99
AGES 7-9
0·6
0·4
0·2
0·0 1..-..&---&..---1-...1.--1----L-.L.-....J
2 3 4 5 6 7 8 9 10
AGE GROUP (YEARS)
Fig. 57. Catch curve of ouananiche from
the Lower Churchill River ahove the site
of the proposed Gull Island dam June-
August, 1975-76. ·
of food sources suggest that landlocked salmon will do well after the river is
impounded.
Reservoir drawdown and siltation may pose a problem for ouananiche.
Fluctuating water levels from the time of spawning in September or October
until the fry emerge from the gravel in May or June may kill the eggs and young
of shore-spawning ouananiche. Fluctuations in water levels may prevent access
to some spawning streams. Siltat.ion of spawning areas will impair egg and fry
survival.
The absence of ouananicne in catches made on the site of the proposed
Muskrat Falls Reservoir suggests that ouananiche should be stocked in the
reservoir to utilize all habitat types. This may be assisted by a natural
colonization.
ROUND WHITEFISH
CATCHES
In the river as a whole, 689 gillnet nights of fishing yielded 169 round
_whitefish weighing 32.8 kg (Fig. 58). Captured fish had a mean length of 26.4 em, a
mean weight of 0.19 kg, and a mean age of 5.8 years.
Catches within the river varied from a high of 0.21 kg/net night in
Section III to a low of 0.01 kg/net night in Sections I, II, and IV (Fig. 59).
Catches tended to be greater upstream of the site of the Gull Island dam.
....
"' ~ 0·2
-0·1
71
Fig. 58. Round whitefish .
Fig. 59. Catches of round whitefish
in five sections of the Lower Churchill
River, June-August, 1975-76.
72
GROWTH IN LENGTH
Round whitefish growth in the Lower Churchill was suggestive of a tendency
towards a maxi.mum ultimate size (Fig. 60 and Appendix V). On the whole, growth
was slightly more rapid than growth in the Smallwood Reservoir (Bruce 1975)
and intermediate to .the range previously reported for North America (Mraz
1964; Mackay and Power 1968).
Growth in the river was most rapid in Section III (between Winokapau Lake
and the site of the Gull Island dam) and slowest below Muskrat Falls (Section
I). I
The age of the oldest round whitefish captured, 13 years, was similar to
that previously reported (Scott and Crossman 1973).
42 ,...-,.-..,...--,--,--,--.,.--,..-,--,---,.--,---,---r--1
40
38
36
34
32
30
j 24
: CJ -· i 22 /;' ~ 20~ 6
:5 1a I/ ~ 16 !;'
14 0·
12 !! 1
10 f
6 X
6-d
r/
6/1
6-6 SECTION II I
x-x SECTION V
O 0 I 2 3 4 5 6 7 8 9 10 II 12 13 14
AGE (YEARS)
GROWTH IN WEIGHT
Fig. 60. Growth of round whitefish
in the Lower Churchill River, 1975-76.
Solid heavy lines approximate minimum
(MacKay and Power 1968) and maximum
(Mraz 1964) rates of.growth in North
America.
Exponents in the length and weight relationships of round whitefish ranged
from 2.62 to 3.19 and had a mean of 2.91 (Table 28); higher than the value of
2.3 reported from the Smallwood Reservoir (Bruce 1975), but lower than the 3.4
value from Ten Mile Lake, Labrador (Parsons 1975). Consistent with growth in
length, round whitefish tended to gain weight faster with increasing length in
Section III where they were longer at a given age.
73
Table 28. Least squares linear regressions of log~0 weight (g) on
log 10 fork length (em) for round whitef1sh from the Lower
Churchill River, June-August 1975-76.
River y Correlation No. of
section intercept Slope coefficient fish
III -2.27 3.19 0.989 116 v -4.48 2.62 0.870 30
Means -3.38 2.91
SEX RATIOS AND MATURITY
The overall sex ratio of captured round whitefish! 1.06, did not indicate
a differential abundance of the sexes (Appendix VI). Sex ratios within river
sections ranged from 0.00 to 3.29 males per female.
Of 169 round whitefish examined, 84.0% were mature (Appendix VII). Each 2 em
length interval from 16 to 44 em contained more than 50% mature fish. The
largest interval containing immature fish was 32.0 to 33.9 em. In the Great
Lakes, round whitefish usually mature iri their third or fourth year (Armstrong
et al. 1977).
FOOD
Round whitefish captured in the Lower Churchill were primarily benthic
insectivores (Table 29) as is usual for this species (Scott and Crossman 1973);
SELECTION BY GEAR
Round whitefish captured above Muskrat Falls were between 10 and 50 em and
had a modal length of between 20 and 30 em (Fig. 61). Ages were from 2 to 13
and had a mode of 3 (Fig. 62).
With all available data combined, mean lengths, weights, and ages tended to
increase with increasing mesh size (Table 30). These trends were less evident
within the individual river secttons (Appendices VIII and IX).
The most efficient mesh size, in terms of weight, was the 7.6 em; capturing
fish with a mean length of 34.9 em, a mean weight of 0.49 kg, and a mean age of
7.7 years.
74
Table 29. Percentage occurrence of major food items in the stomachs of
round whitefish in the Lower Churchill River, June-August 1975-76.
Food item
Trichoptera
Detritus
Plecoptera
Insect remains
Diptera (pupae)
Diptera (larvae)
Invertebrate eggs
Ephemeroptera
Coleoptera
Fish remains
Hymenoptera
Gastropoda
Arachnida
Number of stomachs examined
Number of stomachs empty
100 rr--..----,---,---,...,
!0
80
TO
lO
40
10 ZQ JQ 40 lO
INTERVALS OF rORM L.£HGTH !tift)
River section
III IV v II I-V combined
88.0 100.0 69.2 83.7
48.0 100.0 37.5
41.3 7.7 31.7
22.7 33.3 26.9 24.0
13.3 9.6
9.3 23.1 12.5
9.3 6.7
8.0 5.8
2.7 1.9
2.7 1.9
2.7 1.9
1 . 3. 1.0
1.3 3.8 1.0
75 3 26 104
3 0 4 .. 7
Fig. 61. Length-frequency distribution of round
whitefish from the Lower Churchi 11 River above
Muskrat Falls, June-August, 1975-76.
55
50
45
40
~ 35 ...
~ 30
15 25 .,
~ 20 z
75
N: 141
2 3 4 5 6 7 8 9 10 II 12 13
AGE GROUP (YEARS!
Fig. 62. Age-frequency distribution
of round whitefish from the Lower Churchill
River above Muskrat Falls, June-August,
1975-76.
Table 30. Catch statistics of round whitefish from Sections II-V Of the Lower
Churchill River, June-August 1975-76.
Weight
Mesh No. of No. of No. of Mean Total Mean per net Mean
size net fish fish per length weight weight night age
(em) nights caught net night (em) (kg) (kg) (kg) (yr)
3.8 107 68 0.6 ?1. 0 6.3 0.09 0.06 3.0
5. 1 107 57 0.5 26.9 11.1 o. 19 0.10 4.5
7.6 109 23 0.2 34.9 11.3 0.49 0.10 7.7
10.2 109 3 <0. 1 36.1 2. 1 0.70 0.02 9.7
12.7 107 1 <0.1 29.4 0.3 0.30 <0.01 7.0
MORTALITY RATE
The mortality rate of fish captured above Muskrat Falls (Fig. 6~) at.
M = 0.33 was slightly lower than the 0.45 value for round whitefish from the
Northwest River, Labrador (W. Bruce, pers. comm.).
z.o
1·8
1·6
1·4
1·2
1·0
a.a
0•6
0 4
0·2
M: 0·33
A, 0·28
r '0·88
AGES 4-10
76
0· 0 '--'---L--l...___J__,!.__,I._..L_.J__L........J_..J..--L___._...J
0 I 2 3 4 5 6 7 8 9 10 II 12 13 14
AG£ GROUP :YEARS!
DISCUSSION
Fig. 63. Catch curve of round
whitefish from the Lower Churchill
River above Muskrat Falls, June-
August, 1975-76.
There are indications that round whitefish growth and production will
decrease in the Lower Churchill River after impoundment.
The slightly more rapid growth of round whitefish in the Lower Churchill
River as opposed to the Smallwood Reservoir suggests that, as conditions in the
Lower Churchill approach those of the Smallwood Reservoir, growth rates will
lessen.
The fact that round whitefish catches were greater in rapid-flowing Sections
III and V than they were in Winokapau Lake suggests that, as the river becomes
more of a lake environment, round whitefish production will decrease.
These expected decreases in growth rate and production may be compounded by
a relative abundance of lake whitefish, a potential competitor of round whitefish.
The scarcity of round whitefish in the river below the site of the Muskrat
Falls dam and the expected similarity of conditions in that sector after impoundment
suggest that round whitefish will remain scarce downstream of the impounded area
of the Lower Churchill River.
Of potential harm to round whitefish, as is the case with lake white.fish,
are sedimentation, turbidity, and drawdown~ particularly in the early stages of
the reservoirs.
77
LA KE CHUB
CATCHES
Three lake chub were captured 1n Section III (Fig. 64, Table 31). All were
mature females and taken in the 3.8 em mesh. ·
Fig. 64. Lake chub.
Table 31. Lake chub captured in Section III of
the Lower Churchill River, June-July 1976.
Fork
length Weight Age-group
(em) (kg) (yr)
14.8 0.047 5
15.2 0.043 6
16.5 0.052 8
78
FOOD
All three fish contained insect remains. Trichoptera and plecoptera were
identified in two .
DISCUSSION
As a result of the large mesh sizes employed and the small sample obtained,
the data cannot be considered representative of populations in the Lower Churchil l
Ri ver. The lake chub is potentially valuable as forage for other species. Its
utilization of streams for spawning and its apparent preference for lakes as
opposed to faster waters (Scott and Crossman 1973) suggest that lake chub
production will increase after the Lower Churchill is impounded.
RAINBOW SMELT
CATCHES
Two rainbow smelt were captured in Section I (Fig. 65). Fork lengths were
17 .8 and 19.4 em. Weig hts were, respectively, 53 and 61 g. Both fish were
mature age-group 3 females.
Fig. 65. Rainbow smelt .
FOOD
Both fish contained insect remains and detritus.
DISCUSSION
Apparently, the only smelt in the Lower Churchill are anadromous ones
downstream of Muskrat Falls. It is unlikely that this stock will be harmed by
the creation of the reservoirs provided that conditions downstream of the
Muskrat Falls dam remain fairly similar .
79
OTHER SPECIES
The presence of the following fishes in the Lower Churchill River is
indicated by distribution maps for Canadian fishes presented by Scott and Crossman
(1973),
Arctic char, American eel and Atlantic sturgeon, three sea-run species not
captured during the survey, are apparently confined to waters downstream of the
obstruction at Muskrat Falls as are sea-run brook trout and Atlantic salmon.
These economically valuable species are not likely to be affected by the presence
of the reservoirs providing that an adequate flow of water is maintained downstream
of the reservoir area to allow migration.
Threespine and ninespine sticklebacks, both potentially valuable -forage
species, usually spawn in the summer in nests constructed in shallow water over
sandy or weedy bottom. The young remain near the nest for about two months
after hatching. These species prefer lake rather than river environments and
hence have a potential to increase in abundance after the river is impounded.
Howevf:r, drawdown will adversely affect their reproduction and thus alter
predator-prey relationships in the r~servoirs.
Longnose dace, generally a stream inhabitant and a potentially valuable
forage fish, usually begin spawning in May-July in riffles over a gravelly
bottom. The young remain in quiet areas near shore for about 4 months .. The
preference of the longnose dace for fast waters suggests that it will not be
abundant in the reservoirs. Drawdown and siltation may impair reproductive
success.
Slimy and mottled sculpin are potentially valuable forage fish. They
prefer habitats similar to those of brook trout; suggesting that they will not
become more abun9ant after the river is impounded. Both species spawn in
shallow water in the spring. Drawdown and siltation will be detrimental to eggs
and young. ·
POTENTIAL FISH YIELDS
FISH HARVESTS FROM THE GULL ISLAND AND
MUSKRAT FALLS RESERVOIRS
The specifi:c conductance of the Gull Island and Muskrat Falls Reservoirs
will likely be similar to the 20.7 micromhos/cm measured in the Smallwood Reservoir;
corresponding to a value of total dissolved solids of about 22 ppm (based
on equations of Lennon 1959). This figure, divided by mean reservoir depths,
results in a morphoedaphic index of 1.1 for the Gull Island Reservoir and 1.7
for the Muskrat Falls Reservoir. These values indicate, for large, north-
temperate lakes, maximum sustainable fish yields of, respectively 1.01 and
1.26 kg/ha/yr. In the Gull Island Reservoir, this represents a potential annual
fish harvest of 20,099 kg. In the Muskrat Falls Reservoir, this represents a
potential annual fish harvest of 12,474 kg.
80
The use of Gulland's (197G) mod~l to estimate the components of these
potential yields (Table 32) indicates that just over half of the annual potential
harvest in each reservoir would be made up of the two sucker species. The
remaining portion of the harvest would be comprised of the five most economically
valuable species and burbot (Fig. 66). These estimates are based on the assumption
that lake trout and ouananiche, two species not captured on the site of the
proposed Muskrat Falls Reservoir, colonize the area after construction or are
stocked.
Table 32. Data used in estimating long-term potential fish yield for the
Gull Island Reservoir and the Muskrat Falls Reservoir. Based on
the Ryder (1965) and the Gulland (1970) models and the assumption
that relative fish biomass in the reservoirs will approximate
that in Winokapau Lake.
Yield {kg/ha/~r}
Mortality Relative Gull Island Muskrat Falls
Species rate (Mi) biomass (Bi) Mi Bi MiBi * MiBi t ~MiBi X 1.01 ~~X 1.26
Longnose sucker 0.57 0.289 0.16473 0.299 0.373
White sucker 0.56 0.212 o. 11872 o. 215 0.269
Ouananiche 1 .15 0.076 0.08740 0., 59 0.198
Lake whitefish 0.40 0.132 0.05280 0.096 0.120
Bur bot 0.72 0.060 0.04320 0.078 0.098
Northern pike 0.30 o. 124 0.03720 0.068 0.084
Lake trout o. 41 0.092 o. 03772 0.068 0.085
Brook trout 1.18 0.012 0.01416 0.026 0.0:32
Round whitefish 0.33 0.002 0.00066 0.001 0.002
Totals 1.000 0.55659 1. 01 1.26
*Predicted potential total fish yield based on a morphoedaphic index
(Ryder 1965) of 1.1 for the Gull Island Reservoir.
tPredicted potential total fish yield based on a morphoedaphic index
of 1.7 for the Muskrat Falls Reservoir.
9
0
. g
B
DISCUSSION
D GULL ISLAND
IIIUSKRAT FALLS
81
Fig. 66. Estimated long-term
potential fish yield from the
Gull Island and Muskrat Falls
ReserVoirs.
The estimates of potential fish yields in 'the reservoirs shoUld only be
considered as preliminary guidelines to be used until data· are acquired after
impoundment. The estimates· of total yield are based en the rela·tionship
between yield and the morphoedaphic index in large, north-temperate lakes.
Anomalous environmental conditions such as frequent drawdowns will decrease
the potential harvest. Also, as pointed out by Henderson et al; (1973), 1t
can be expected that the potential· yield predicted by the morphoedaphic index
may be exceeded before a reservoir has attained biotic stability and afterwards
may not be .. met unless fishing effort is moderately intense and constant.
Tpe method employed to estiimate the c'omponent yields required the assumptions
that mortality rates did not change ~ignificantly from one portion of the
river to another, that the exploitable species were caught in proportion to
their abundance, and that the relative abundance and population dynamics of a
given species in, Winokapau Lake are. not significantly different from what
they will be in the proposed reservoirs. This latter assumption will be invalid
if excessive drawdowns and siltation occur causing mortality rates ·to increase
and co~unity stability to decrease or if lake trout and ouananiche do not
inhabit the Muskrat Falls Reservoir.
For the above reasons and for the purpose of accurately quantifying
the effect of the impoundment of Labrador rivers, it is desirable to undertake
a continuous monitoring of the fishery of the Gull Island and Muskrat Falls
Reservoirs~
It is unlikely that the estimated annual yields of fishes from the proposed
-reservoirs could support an economically viable commercial fishery. However,
if a fishery is undertaken, consideration should be given to problems posed by
infestations of species of the parasite Triaenophorus and excessively high
levels of mercury as were found in fish flesh in the Smallwood Reservoir
and Winokapau Lake (Bruce et al. 1979). Both of these will affect the marketability
of the product.
82
SUMMARY
1. The fish populations and water quality of the Lower Churchill River,
Labrador, were surveyed from June to August, 1975-76; prior to the proposed
creation of the Gull Island and Muskrat Falls Reservoirs to be used for
hydroelectric power.
2. Overall, the Lower Churchill River is characterized by a pH of 6.3, a
conductance of 18.9 ~has/em, a total hardness of 8 ppm, a total alkalinity
of 6 ppm, a calcium concentration of 1.4 ppm, a turbidity of 3.4 JTU, and
a chloride concentration of 0.8 ppm. Tributaries of the Lower Churchill
tend to be more dilute waters.
3. Eleven of the 19 fish species whose presence is indicated by distribution
maps (Scott and Crossman 1973) were captured with gillnets during the
survey. These were: northern pike, lake whitefish, longnose sucker, white
sucker, brook trout, burbot, lake trout, ouananiche, round whitefish, lake
chub, and rainbow smelt. Threespine sticklebacks and a species of sculpin
were identified in stomach contents. All species identified, except rainbow
smelt, were obtained upstream of the impassable barrier to fishes, Muskrat
Falls. All species identified, except lake trout, ouananiche, lake chub
and the species of sculpin, were obtained downstream of Muskrat Falls.
4. The mdst numerous of the species captured in the river as a whole were,
respectively, longnose sucker, lake whitefish, white suckers, brook trout,
and northern pike. In terms of. weight, northern pike was most abundant
followed by lake whitefish, longnose suckers, white suckers and brook
trout.
5 .. The relative abundance, growth rates, sex ratios and stomach .contents of
the species captuted varied from section to section throughout the river.
6. In the river as a whole, northern pike growth is rapid compared to that in
other northern Canadian waters including the Smallwood Reservoir. Pike
mature at about 40 em and 3-4years of age. They are primarily piscivorous.
Pike were caught most efficiently in 10.2 em mesh gillnets. Pike taken in
this mesh size were all age 5 and over and 50 em-or larger.
7. Lake whitefish in the river are slow growing in comparison to those in
other Canadian waters inc.luding the Smallwood Reservoir. They mature at
about 21 em and 2-4 years of age. They are primarily benthic insectivores.
Nearly all of the fish captured in the most efficient mesh size, 7.6 em,
were age 4 and over and 30 em or larger.
8. Longnose suckers in the Lower Churchill grow at a rate similar to that in
the Smallwood Reservoir and are comparatively slow growing. They mature at
about 20 em and 5 or 6 years of age. They feed primarily on benthic
invertebrates. Nearly all of the fish captured in the most efficient mesh
size, 7.6 em, were age 7 and over and 30 em or larger.
83
9. White suckers in the Lower Churchill grow at a rate close to the middle of
the range in Canadian waters. They mature at about 22 em and 4-5 years of
age. They feed primarily on benthic invertebrates. The most efficient
mesh size, 10.2 em, captured fish age 7 and over and 30 em or larger.
10. Brook trout in the Lower Cnurchill River grow at a rate intermediate to the
range in Newfoundland and Labrador and slower than those in the Smallwood
Reservoir. They mature at about 17 em and 2-3 years of age and feed primarily
on benthic invertebrates. Brook trout were caught most efficiently in
7.6 em mesh gillnets. Nearly all of the fish taken in this mesh size were
age 3 and over and 30 em or larger.
11. Burbot in the Lower Churchill River grow at a rate within the range previously
documented for this species in Canada and mature at about 20 em and 5-6
years of age. They feed primarily on benthic invertebrates. Nearly all of
the fish captured in the most efficient mesh size, 10.2 em, were age 7 and
over and 30 em or larger.
12. Lake trout growth rates in the Lower Churchill River are intermediate to
the overall range ahd similar to those in the Smallwood Reservoir. On the
basis of a small sample size, they mature at about 35 em and 6 years of
age. They are primarily piscivorous and were caught most efficiently in
10.2 em mesh gillnets.
13. Ouananiche in the Lower Churchill River have relatiyely high growth rates;
similar to those in western Labrador. They are primarily piscivorous. The
3.8 and 10.2 em mesh gillnets were equally efficient for the capture of
ouananiche. ·
14. Round whitefish in the Lower Churchill River have a growth rate slightly
greater than that in the Smallwood Reservoir and intermediate to the North
American range. They are primarily benthic insectivores and were most
efficiently caught in 7.6 em mesh gillnets.
15. Long-term potential fish yields in the Gull Island Reservoir were estimated
to be 1.01 kg/ha/yr or 20,099 kg/yr with just over half of this potential
to be made up of longnose and white suckers. In estimating this yield the
author assumed that stress conditions such as excessive drawdown and
sedimentation would not occur.
16. Long-term potential fish yields in the Muskrat Falls Reservoir were estimated
to be 1.26 kg/ha/yr or 12,474 kg/yr with just over half made up of longnose
and white suckers. In estimating the yield the author assumed that stress
conditions would not occur and that lake trout and ouananiche would colonize
the reservoir or be introduced.
17. Of greatest potential harm to fish populations in the Lower Churchill River
as a result of impoundment are fluctuating water levels and increased
sedimentation.
84
ACKNOWLEDGMENTS
The entire staff of the Inland Fisheries a~d Habitat Protection Section,
Freshwater and Anadromous Fisheries Management Program, contributed in some way
to the making of this report from its conception to its completion. The following
individuals played major roles.
C. Morry and W. Bruce planned and implemented the study and supervised the
collection of data.
L. Cole collected and processed much of the data and assisted throughout
all phases of the study.
D. Riche processed much of the data; in particular the age and growth data.
R. Parsons collected and processed the large part of the data from study
Section V.
A. Jamieson was responsible for laboratory water quality analyses.
P. Downton, G. Furey, D. Scott, C. Walters and J. Wheeler assisted in data
collection and processing.
H. Mullett drafted the figures and G. King assisted with photographic
reproduction.
J. Lannon, K. Scott and C. Walsh typed the report.
H. Bain, W. Bruce, L. Cole, E.M.P. Cha.dwick, J. Pippy, and R. J. Wiseman
reviewed the manuscript and provided helpful criticisms.
85
REFERENCES
Acres Consulting Services Limited. 1978. Churchill River power and energy
studies. Rep. to Nfld. and Lab. Hydro: 33 p.
American Public Health Association, American Water Works Association and Water
Pollution Control Federation. 1971. Standard methods for the examination
of water and wastewater including bottom sediments and sludges, 13th ed.
American Public Health Association, Inc., New York: 1193 p.
Armstrong, J. W., C. R. Liston, P. I. Tack, and Robert C. Anderson. 1977. Age,
growth, maturity, and seasonal food habits of round whitefish, Prosopium
cyZind:!'aceum, in Lake Michigan near Ludington, Michigan. Trans. Am. Fish.
Soc. 106: 151-155.
Baranov, I. V. 1961. Biohydrochemical classification of the reservoirs in the
European U.S.S.R., p. 139-183. In P.V. Tyurin, ed. The storage lakes of
the U.S.S.R. and their importan~e for fishery. Izv. Gos. Nauchno-ISSLED.
Inst. Ozer. Rech. Rybn. Khoz. Vol. 50.
Beamish, R. J. 1973. Determination of age and growth of popufations of the
white suckers (Catostomu.s commersoni) exhibiting a wide range in size at
maturity. J. Fish. Res. Board Can. 30: 607-616. ·
Beamish, R. J., and H. H. Harvey. 1969. Age determination in the white sucker.
J. Fish. Res. Board Can. 26: 633-638.
Beamish, R. J., L. M. Blouw, and G. A. McFarlane. 1976. A fish and chemical
study of 109 lakes in the experimental lakes area (ELA), Northwestern
Ontario, with appended reports on lake whitefish ageing errors and the
northwestern Ontario baitfish industry. Fish. Mar. Serv. Tech. Rep. 607:
116 p.
Bruce, W. J. 1974. The limnology and fish populations of Jacopie Lake, West
Forebay, Smallwood Reservoir, Labrador. Fish. Mar. Serv. Tech. Rep. Ser.
No. NEW/T-74•2z 74 p.
1975. Experimental gillnet fishing at Lobstick and Sandgir,t L~kes,
Smallwood Reservoir, western Labrador, 1974. Fish. Mar. Serv. Intern. Rep.
No. NEW/I-75-4: 35 p.
1976. -Age, growth, maturity and food habits of landlocked salmon
(SaZmo saZar) in Soldier's Pond, a Newfoundland lake. Fish. Mar. Serv~
Tech. Rep. 668: 16 p.
Bruce, W. J., and R. F. Parsons. 1979. Biology of the fishes of the Ossokmanuan
Reservoir, Lc.brador, 1976. Fish. Mar. Serv. Tech. Rep. 836: iv + 33 p.
Bruce, W. J., K. D. Spencer, and E. Arsenault. 1979. Mercury content data for
Labrador fishes, 1977-78. Fish. Mar. Serv. Data Rep. 142: iv + 263 p.
-Casselman, J. M. 1975. Sex ratios of northern pike, Esox Zucius Linnaeus4
Trans. Am. Fish. Soc. 104: 60-63.
86
Duthie, H. C., and M. L. Ostrofsky. 1974. Plankton, chemistry and physics of
lakes in the Churchill Falls region of Labrador. J. Fish. Res. Board Can.
31: 1105-1117.
1975. Environmental impact of the Churchill Falls (Labrador) hyrdoelectric
project: a preliminary assessment. J. Fish. Res. Board Can. 32: 117-125.
Flick, W. A. 1977. Some observations, age, growth, food habits and vulnerability
of large brook trout (SaZveZinus fontinaZis) from four Canadian lakes.
Nat. Can. 104: 353-359.
Geen, G. H. 1974. Effects of hydroelectric development in.western Canada on
aquatic ecosystems. J. Fish. Res. Board Can. 31: 913-927.
Gulland, J. A. 1970. The fish resources of the oceans. FAO Fish. Tech. Pap.
97: 425 p.
Gull Island Power Company Limited. 1977. Project description of Gull Island
Power Site Project. Newfoundland and Labrador Hydro: 23 p.
Harris, R.H.D. 1962. Growth and reproduction of longnose sucker, Catostomus
aatosomus Forster, in Great Slave Lake. J. Fish. Res. Board Can. 19: 113-126.
Harvey, H. H. 1976. Aquatic environmental quality:
Fish. Res. Board Can., Background Study, No. 11:
problems and proposals.
l2Q p.
Havey, K. A., and K. Warner. 1970. The landlocked salmon (SaZmo saZar). Its
life history and management in Maine. Sport Fish. Inst. Washington, and
Maine Rep. Inland. Fish. Game: 129 p.
Healey, M. C. 1975. Dynamics of exploited whitefish populations and their
management with special reference to the Northwest Territories. J. Fish.
Res. Board Can. 32: 427-448.
1978. The dynamics of exploited lake trout populations and implications
for management. J. Wildl. Man. 42(2): 307-328.
Henderson, H. F., R. A. Ryder, and A. W. Kudhongonia. 1973. Assessing fishing
potentials of lakes and reservoirs. J. Fish. Res. Board Can. 30: 2000-2009.
Lawler, G. H. 1963. The biology and taxonomy of the burbot, Lata Zotc;r.,
in Heming Lake, M~nitoba. J. Fish. Res. Board Can. 20: 417-433.
Leggett, W. C., and G. Power. 1969. Differences between two populations of
landlocked Atlantic salmon (SaZmo salar) in Newfoundland. J. Fish. Res.
Board Can. 26: 1585-1596.
Lennon, R. E. 1959. The electrical resistivity meter in fishery investigations.
U.S. Fish and Wildl. Serv., Spec. Dir. Rept. Fish. No. 287: 13 p.
Lopoukhine, N., N. A. Prout, and H. E. Henderson. 1978. Ecological land
classification of Labrador; a reconnaissance. Lands Directorate (Atl.
Reg.) Environmental Management Serv. Fish. and Envir. Can. Halifax, N.S.
Ecological Class. Ser. No. 4: 85 p.
87
Lower Churchill Development Corporation Limited. 1979. L.C.D.C. Project
Outline. Rep. to Newfoundland and Labrador Hydro: 7 p.
Machniak, K. 1975a. The effects of hydroelectric development on the biology of
northern fishes (reproduction and population dynami~s). II. Northern pike
Eso:x: l.uc:ius (Linnaeus). A literature review and bibliography. Fish. Mar.
Serv. Tech. Rep. 528: 82 p.
1975b. The effects of hydroelectric development on the biology of
northern fishes (reproduction and population dynamics). I. Lake whitefish
Coregonus c:l.upeafoi'!nis (Mitchill). A literature review and bibliography.
Fish. Mar. Serv •. Tech. Rep. 527: 67 p.
1975c. The effects of hydroelectric development on the biology of
northern fishes (reproduction and population dynamics). IV. Lake trout
Sal.vel."fnus namayc:ush (Walbaum). A literature review and bibliography.
Fish. Mar. Serv. Tech. Rep. 530: 52 p.
Mackay, I., and G. Power. 1968. Age and growth of round whitefish (P:t>osopium
c:yl.indrac:eum) from Ungava. J. Fish. Res. Board Can. 25: 657-666.
'i
McCrimmon, H. R., 'and O.E. Devitt. 1954. Wintfi!r studies on the burbot, Lota
l.ota l.ac:ustris, of Lake Simcoe, Ontario. Can. Fish Cult. 16: 34-41.
Miller, R. B., and W. A. Kennedy. 1948. Pike (Eso:x: l.uc:ius) from four northern
Canadian lakes. J. Fish. ~es. Board tan. 7: 190-199.
Marry, C. J., and L. J. Cole. 1977. Limnology and fish populations of Red
Indian Lake, a multi-use reservoir. Fish. Mar. Serv. Tech. Rep. 691: 109 p.
Mraz, D. 1964. Age and growth of the round whitefish (Prosopium c:yUndrac:eum)
in Lake Michigan. Trans. Am. Fish. Soc. 93(1): 46-53.
Parsons, R. F. 1975. The limhology and fish biology of Ten Mile Lake, Labrador.
Fish. Mar. Serv. Tech. Rep. Ser. No. NEW/T-75-3. ·
Pippy, J.H.C. 1966. A biological and ecological study of the Salmonidae of
Victoria Lake. Fish. Mar. Serv. Prog. Rep. No. 38: 104 p.
Rawson, D. S., and C. A. Elsey. 1950. Reduction in the longnose sucker population
of Pyramid Lake, Alberta, in an attempt to improve angling. Trans. Am.
Fish. Soc. 78(1948): 13-31.
Reed, E. B. 1962. Limnology and fisheries of the Saskatchewan River in Saskatchewan.
Fish. Branch Dep. Natur. Res. Sask. Fish. Rep. 6: 48 p.
Riche, L. G. 1965. A preliminary biological survey of the Naskaupi, Kenamu,
and Lower Churchill Rivers. Fish. Mar. Serv. Rep., March 1965: 82 p.
Ricker, W. E. 1975. Computation and interpretation of biological statistics of
fish populations. Fish. Res. Board Can. Bull. 191: 382 p.
Ryder, R. A. 1965. A method for estimating the potential fish production of
north-temperate lakes. Trans. Am. Fish. Soc. 94: 214-218.
88
Ryder, R. A., and H. F. Henderson. 1975. Estimates of potential fish yield for
the Nasser Reservoir, Arab Republic of Egypt. J. Fish. Res. Board Can.
32: 2137-2151.
Ryder, R. A., S. R. Keer, K. H. Loftus, and H. A. Regier. 1974. The morphoedaphic
index, a fish yield estimator-review and evaluation. J. Fish. Res. Board
Can. 31: 663-688.
Scott, W. B., and E. J. Crossman. 1964. Fishes occurring in the fresh waters
of insular Newfoundland. Dep. Fish. Ottawa: 124 p.
1973. Freshwater fishes of Canada. Fish. Res. Bo.ard Can. Bull . 184:
966 p.
Tesch, F. W. 1971. Age and growth. p. 93-120. In W. E. Ricker, ed. Methods
for assessment of fish production in fresh waters. 2nd ed. I.B.P. Handbook,
No. 3, Blackwell Scientific Publications Oxford: 348 p.
Thurlow and Associates, Environmental Control Consultants Limited in association
with Foundation of Canada Engineering Corporation Limited, 1974. Preliminary
Environmental overview of the Lower Churchill Power Development Rep. to
Dept. Prov. Affairs and Env. Govt. Newfoundland and Labrador: 31 p.
Van Engal, W. A . .1940. The rate of growth of the northern pike Esox tuaius
Linnaeus, in Wisconsin waters. Copeia 1940(3): 177-188.
Wetzel, R. G. 1975. Limnology. W. B. Saunders Co., Toronto: 743 p.
Whelan, W. G., and R. J. Wiseman. The limnology and sport fish populations of
three lakes located on the sputhern shore, Avalon Peninsula, Newfoundland.
Fish. Mar. Serv. Data ReP~· 26: 28 p.
Wiseman, R. J. 1971. The limnology, ecology and sport fishery of Thomas Pond:
a multi-use reservoir. Fish. Mar. Serv. Prog. Rept. 73: 133 p.
Wolfert, D. R., and T. J. Miller. 1978. Age, growth, and food of northern pike
in Eastern Lake, Ontario. Trans. Am. Fish. Soc .. 107(5): 696-702.
89
Appendix I
Sample Sites
( i) Section I
( i i) Section II
(iii) Section III
(iv) Section IV
(v) Section V
(vi) The Tributaries
91
Appendix I(i). Sample sites in Section I of the Lower Churchill
River, June 28-July 4, 1975.
N == net set
w-water sample
5km. I
92
Appendix I(ii). Sample sites in Section II of the Lower Churchill
River, August 3-24, 1975.
N= net set
W = water sample
5 km.
93
Appendix I(iii). Sample sites in Section III of the Lower Churchill
River, June 21-July 29, 1976
N = net set
W = water sample
5 km.
17 14
94
Appendix I(iv). Sample sites in Section IV of the Lower Churchill
River, July 31-August 5, 1976.
N =net set
W =water sample
5 km. 1
95
Appendix I(v). Sample sites in Section V of the Lower Churchill
River, July 17-August 6, 1975.
I
Ill
I·
N = net set
w = water sample
5km.
96
Appendix I(vi). Location of the mouths of tributaries to the Churchill
River from which water samples were obtained in 1976.
Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Location
53°15'40 11 N
60°31'30"W
53°14'15"N
60°43'50"W
53°14'30"N
60°51'45"W
53°10'15"N
60°56'00"W
53°0l'OO"N
61°15'30"W
52°59'00"N
61°16'30"W
52°59'30"N
60°36'40"W
52°5~1 30"N
62°37'20"W
52°53'40"N
61°50'50"W
53°04'30"N
62°13'00"W
53°06'30"N
62°22'30"W
52°12'00"N
63°12'00"W
53°14'30"N
63°18'00"W
53°18'45"N
63°22'15"W
53°19'40"N
63°25'00"W
Tributary
Caroline Brook
MacKenzie River
Lower Brook
Upper Brook
Pinus River
Unnamed-south side of the
Churchill below Gull Lake
Unnamed-north side of the
Churchill at Horseshoe Rapids
Minipi Riyer
Dominion River
Cache River
Shoal River
Fig River
Elizabeth River
Metchin River
Unnamed-north side of the
Churcniill above the Metchin
97
Appendix II
Individual measurements of water quality, Lower Churchill River
99
AppendiX II • Individual measurements of water quality, Lower Churchill River.
Total Conductance Total
Sample Sample hardness (!Jmhos/cm Turbidity alkalinity Calcium Chloride
date site pH (ppm) at 25°C) (JTU) (ppm) (ppm) (ppm)
28 6 75 w 1 6.6 5 14.3 3.5 4 0.8 1.0
30 6 75 w 2 6.8 5 15.4 4.0 5 0.9 1.0
3 6 75 w 3 6.4 8 15.4 4.0 4 0.9 1.0
5 6 75 w 4 6.3 6 16.5 5.0 5 1.0 1.0
5 6 75 w 5 6.6 7 17.4 20.0 5 1.0 1.0
7 6 75 w 6 6.6 7 17.4 14.0 5 1.0 1.0
10 6 75 w 7 6.1 6 18.0 11.0 5 1.0 1.0
11 6 75 w 8 6.0 10 18.3 16.5 5 1.0 1.0
13 6 75 w 9 6.3 7 19.1 20.0 6 1.1 1.0
14 7 75 w 10 6.2 8 18.8 10.0 6 1.4 1.0
3 8 75 Wll 6.2 8 18.0 6.0 3 1.1 1.0
5 8 75 w 12 6.0 8 19.1 3.5 5 1.4 1.0
6 8 75 w 13 6.1 8 19.7 9.0 4 1.4 1.0
7 8 75 w 14 6.2 6 20.9 4.0 5 1.1 2.0
9 8 75 w 15 6.2 7 18.6 4.5 6 1.4 1.0
10 8 75 w 16 6.1 8 18.1 4.5 6 1.3 1.0
14 8 75 w 17 6.1 7 18.1 5.5 6 1.4 1.0
15 8 75 w 18 6.1 7 18.7 9.0 6 1.4 1.0
17 8 75 w 19 6.1 7 18.7 6.0 5 1.2 1.0
18 8 75 w 20 6.2 8 19.2 3.5 6 1.5 1.0
21 8 75 w 21 6.0 9 20.3 5.5 5 1.1 1.0
21 8 75 w 22 6.5 8 18.7 4.0 7 1.4 1.0
22 8 75 w 23 6.4 8 18.7 5.0 7 1.2 1.0
23 8 75 w 24 6.3 8 18.7 9.0 6 1.1 1.0
20 6 76 w 25 6.3 8 17.0 1.0 5 1.2 0.6
20 6 76 w 26 6.2 7 17.0 0.8 4 1.3 0.7
23 6 76 w 27 6.4 8 18.0 0.8 5 1.3 0.6
22 6 76 w 28 6.3 8 18.0 0.8 5 1.3 0.6
24 6 76 w 29 6.3 8 18.0 0.6 5 1.3 0.6
24 6 76 w 30 6.3 8 19.0 !.2 5 1.2 0.6
27 6 76 W31 6.4 8 17.0 1.4 5 1.1 0.6
27 1 76 w 32 6.2 8 17.0 0.5 5 1.3 0.6
27 1 76 w 33 6.4 7 17.0 0.6 5 1.3 0.6
27 7 76 w 34 6.3 8 19.0 2.0 5 1.3 0.6
21 7 76 w 35 6.2 10 22.0 1.0 6 2.0 0.6
21 7 76 w 36 6.3 10 20.0 0.7 5 1.6 0.7
23 7 76 w 37 6.5 10 20.0 2.5 7 1.8 0.7
23 7 76 w 38 6.5 10 20.0 1.2 8 1.8 0.6
24 7 76 w 39 6.2 10 19.0 1.0 6 2.0 0.7
24 7 76 w 40 6.3 10 19.0 1.0 6 1.6 0.6
29 7 76 w 41 6.3 10 20.0 0.5 5 1.7 0.7
25 7 76 w 42 6.4 10 19.0 1.1 6 1.6 0.8
26 7 76 w 43 6.2 9 21.0 0.8 7 1.6 0.6
26 7 76 W44 6.3 10 18.0 1.5 .6 1.3 0.8
27 7 76 w 45 6.5 10 18.0 0.5 5 1.4 0.8
27 7 76 w 46 6.5 8 20.0 0.8 8 2.0 0.6
28 7 76 w 47 6.6 8 20.0 0.7 8 2.0 0.6
28 7 76 w 48 6.3 8 19.0 1.5 7 2.0 0.6
29 7 76 w 49 6.4 10 18.0 4.0 5 1.8 0.8
29 7 76 w 50 6.3 10 19.0 0.5 6 1.7 0.7
31 7 76 w 51 6.4 9 21.0 2.2 7 1.8 0.6
31 7 76 w 52 6.4 9 20.0 1.5 7 1.5 0.6
1 8 76 w 53 6.3 8 18.0 1.2 5 1.4 0.6
1 8 76 w 54 6.4 9 21.0 0.7 6 1.7 0.6
2 8 76 w 55 6.5 9 22.0 1.5 6 1.6 0.7
2 8 76 w 56 6.2 10 21.0 0.9 6 1.6 0.6
3 8 76 w 57 6.3 9 19.0 1.0 6 1.3 0.6
3 8 76 w 58 6.3 10 19.0 1.2 7 1.4 0.6
4 8 76 w 59 6.3 7 18.0 0.6 6 1.3 . 0.6
4 8 76 w 60 6.3 8 18.0 1.4 5 1.3 0.6
5 8 76 w 61 6.4 8 19.0 1.0 6 1.5 0.6
5 8 76 w 62 6.3 8 18.0 0.8 6 1.6 0.7
6 8 75 w 63 6.4 10 20.9 1.5 6 1.1 0.5
5 8 75 w 64 6.4 8 17.1 0.7 6 1.1 0.5
5 8 75 w 65 6.1 6 13.2 0.3 4 0.8 0.5
27 7 75 w 66 6.4 10 20.9 0.9 8 1.1 0.5 30 7 75 w 67 6.5 12 26.4 1.5 8 2.3 0.5 27 7 75 w 68 6.4 10 20.4 1.6 8 1.7 1.0 27 7 75 w 69 6.5 10 20.4 1.7 8 1.3 1.0 25 7 75 w 70 6.5 10 22.0 3.7 8 1.7 1.5 20 7 75 W7l 6.4 8 22.0 1.5 6 1.3 0.5
101
Appendix III
Composition of the gillnet catch
(i) Numbers
(ii) Number/unit effort
(iii) ~·!eight
(iv) Weight/unit effort
103
Appendix III(i). Numerical composition of the gillnet catch by species in
the Lower Churchill River, June-August, 1975-76. Percentages
are shown in brackets. ·
River section
Species I II III IV v I-V
Longnose sucker 289 55 268 170 409 1191
(30.3) (10.5) (26.9) (41.2) (40.9) (30.6)
Lake whitefish 294 145 119 58 221 . 837
(30.8) (27. 7) (12.0) (14.0) ( 22. 1 ) ( 21 . 5)
White sucker 252 171 20 113 155 711
(26.4) (32.7) (2.0) (27.4) (15.5) (18. 3)
Brook trout 38 3 446 5 87 579
(4.0) (0.6) (44.8) (1. 2) (8.7) (14.9)
Northern pike 55 133 1 16 60 265
( 5. 8) (25.4) ( 0.1) (3.9) (6,0) (6.8)
Round whitefish 17 3· 116 3 30 169
(1 .8) (0.6) (11.6) (0. 7) (3.0) (4.3)
Burbot 7 13 18 23 24 85
(a·. 7) (2.5) (1.8) (5.6) (2.4) (2.2)
Ouananiche 2 17 11 30
(0.2) (4.1) (1.1) (0.8)
Lake trout 3 8 4 15
(0.3) (1 .9) (0.4) (0.4)
Lake chub 3 3
(0.3) ( 0.1 )
Rainbow smelt 2 2
(-) (-)
All species
954 523 996 413 1001 3887
104
Appendix III(ii). Catch per unit effort (No. fish/net night)a of the gillnet
catch by species in the Lower Churchill River. June-August,
1975-76. Percentages are shown in brackets.
River section
Species I II III IV v I-V
Longnose sucker 1.9 0.3 2.3 2.8 2.8 1.7
(29.2) (12.0) (26. 7) (40.0) (40.6) (30.9)
Lake whitefish 2.0 0.7 1.0 1.0 1.5 1.2
(30.8) (28.0) (11.6) (14.3) ( 21 . 7) ( 21 . 8)
White sucker 1.7 0.8 0.2 1.9 1 . 1 1.0
(26.2) (32.0) (2.3) (27.2) (15.9) (18.2)
Brook trout 0.3 <0.1 3.9 0.1 0.6 0.8
(4.6) (-) (45.4) ( 1 . 4) (8.7) (14.5)
Northern pike 0.4 0.6 <0 .1 0.3 0.4 0.4
(6.2) (24.0 (-) (4.3) ( 5.8) (7.3)
Round whitefish 0.1 <0 .1 1.0 0.1 0.2 0.3
( 1 . 5) (-) (11.6) (1.4) ( 2. 9) ( 5. 5)
Bur bot 0.1 0.1 0.2 0.4 0.2 0.1
( 1 . 5) (4.0) (2.3) (5. 7) (2.9) ( 1 . 8)
Ouananiche <0.1 0.3 0.1 <0 .1
(-) (4.3) (1. 5) (-)
Lake trout <0.1 0.1 <0.1 <0 .1
(-) ( 1 . 4) (-) (-)
Lake chub <0.1 <0 .1
(-) (-)
<0.1 <0 .1 Rainbow smelt (-) (-)
All species 6.5 2.5 8.6 7.0 6.9 5.5
aA net night is one 47 metre gillnet of stretched mesh 3.8 -12.7 em fished
for a 24 hour period. Data are weighted to compensate for different efforts
by different mesh sizes.
105
Appendix III(iii). Weight composition (kg) of the gillnet catch by species in
the Lower Churchill River, June-August, 1975-76. Percentages
are shown in brackets.
River section
Species I II III IV v I-V
Northern pike 118.3 246.0 2.3 37.4 145.8 549.8
(30.2) (54. 7) (0.5) (12.5) (22.9) (24.8)
Lake whitefish 127.1 78.2 78.3 39.3 146.1 469.0
(32.4) (17 .4) (17.9) (13.2) (22.9) (21.2)
Longnose sucker 70.4 21.1 98.0 86.1 125.9 401.5
(18.0) (4. 7) (22.4) (28.8) (19.8) (18.1)
White sucker 64.9 90.4 12.1 63.4 122.6 353.4
(16.6) (20.1) (2.8) (21. 2) (19.3) (16.0)
Brook trout 5.0 1.1 209.5 3.7 42.3 261 .6
( 1 . 3) (0.2) (47.8) (1 .2) (6.6) (11.8)
Bur bot 4.3 10.9 9.3 17.8 17.6 59.9
(1.1) (2.4) (2. 1) (6.0) (2.8) (2 .7)
Lake trout 2.7 27.8 21.3 51.8
(0.6) (9.3) (3.3) (2.3)
Ouananiche 1.2 23.0 11 .1 35.3
(0.3) (7. 7) (1. 7) (1. 6)
Round whitefish 1.7 1.9 24.6 0.4 4.2 32.8
(0.4) (0.4) (5.6) (0.1) (0. T) ( 1 . 5)
Lake chub 0.1 0.1
(-) (-)
Ra i nb.ow sme 1t 0.1 0.1
(-) (-)
All species 391.8 449.6 438.1 298.9 636.9 2215.3
106
Appendix III(iv). Catch per unit effort (kg/net night)a of the gillnet
Species
Northern pike
Lake whitefish
Longnose sucker
White sucker
Brook trout
Burbot
Lake tro·ut
Ouananiche
Round whitefish
Lake chub
Rainbow smelt
A 11 species
catch by species in the Lower Churchill River, June-August,
1975-76. Percentages are shown in brackets.
River section
I II III IV v I-V
0.79 1.12 0.02 0.62 0.98 0.80
(30.3) (54.4) ( 0. 5) (12.4) (22. 7) (24.8)
0.85 0.36 0.68 0.66 0.98 0.68
(32.6) (17.5) (17 .9) (13.2) (22. 7) ( 21.1)
0.47 0.10 0.85 1.44 0.86 0.58
(18.0) (4.9) (22.4) (28. 9) (20.0) (18.0)
0.43 0.41 0.11 1.06 0.82 0. 51
(16.5) (19.9) (2.9) ( 21 . 2) (19.0) (15.8)
0.03 0.01 1 .82 0.06 0.29 0.38
( 1 . 2) (0.5) (47.9) (1. 2) (6. 7) (11.8)
0.03 0.05 0.08 0.30 0.12 0.09
( 1 . 2) (2 .4) ( 2.1) (6.0) (2.8) (2.8)
0.02 0.46 0.15 O.()D
( 0. 5) (9.2) (3.5) (2.5)
0.01 0.38 0.08 0.05
( 0.3) (7.6) ( 1 . 9) (1. 6)
0.01 0.01 0.21 0. 01 0.03 0.05
(0.4) (0.5) (5.5) (0.2) (0.7) (1.6)
<0.01 <0.01
(-) (-)
<0.01 <0. 01
(-) (-)
2.61 2.06 3.80 4.99 4.31 3.22
aA net night is one 47 metre gillnet of stretched mesh 3.8 -12.7 em fished for
Data are weighted to compensate for different efforts by a 24 hour period.
different mesh sizes ..
107
Appendix IV
Body-scale relationships of fishes from the Lower Churchill River
Appendix IV. Linear regressions of fork length (L)(cm) on scale radius (S)(cm x 43) for fishes
from the Lower Churchill River, 1975-76.
River Regression No. of Correlation
Species Section data pairs Coefficient
Northern I. log 10 L = 0.74 log 10 S + 0.93 55 0.923'
pike II. 1og 10 L = 0.84 log 10 S + 0.83 131 0.932
IV. 1og 10 L = 0.88 log 10 S + 0.55 117 0.918 v. : L = 4.70 S-6.10 60 0.900
Lake I. L = 1.06 s + 8.78 150 0.904
whitefish II. L = 1.11 s + 8.37 140 0.936
III. log 10 L = 0.46 log 10 S + 0.94 104 0 •. 794
IV. L = 1.10 S + 12.86 54 a 0.867 v. L = 2.57 s + 9.07 10 0.983
Long nose
sucker I. log 10 L = 0.67 1og 10 S + 0.78 148 0.895
II. 53 0.926 1-' log 10 L = 0.73 log 10 S + 0.69 0
III. 189 0.889 1.0 log 10 L = 0.72 log 10 S + 0.73
IV. log 10 L = 0.57 log 10 S + 0.89 95a 0.849 v. L = 2.39 S + 0.41 7 0.993
White I. 1og 10 L = 0.62 1og 10 S + 0.69 182 0.938
sucker II. . L = 1.13 S + 7.68 150 0.900
III. 1og 10 L = 0.54 1og 10 S + 0.82 20 0. 961
IV. L = 1.05 S + 10.50 102a 0. 951 v. L = 2. 32 s + 7.66 9 0.991
Brook I. 1og 10 L = 0.58 1og 10 S + 1.13 37 0.750
trout III. 1og 10 L = 0.94 1og 10 S + 1.03 183 0.844 v. log 10 L = 1.11 1og 10 S + 0.86 87 b
Ouananiche IV. L = 2.74 s + 8.66 22 0.875
Round III. L = 1. 62 s + 8.14 105a 0.929
whitefish v. L = 2.65 s -2.09 8 0.985
a. Data were averaged by intervals of fork length.
b. Not available.
111
Appendix V
Age-Length Data
(i) Northern Pike
(ii) Lake Whitefish
(iii) Longnose Suckers
(iv) White Suckers
(v) Brook Trout
(vi) Burbot
(vii) Lake Trout
(viii) Ouananiche
(ix) Round Whitefish
Appendix V(i). Growth of northern pike, Esox lucius, in four sections of the Lower Churchill River, Labrador, June-August, 1975-76.
River Mean calculated fork length {em} at age -No. of
section 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 fish
13.1 25.8 34.7 41.7 48.4 53.4 58.3 62.5 65.3 67.1 66.2 55
II 11.8 20.2 29.5 38.1 45.3 50.7 55.9 60.1 63.1 66.1 68.7 71.6 74.1 74.9 78.1 84.6 131
IV 8.7 15.9 23.1 31.6 42.6 50.6 56.8 59.0 64.2 64.6 66.0 70.2 74.0 78.2 16
v 1.7 12.9 " 25.3 37.9 49.9 58.0 63.7 69.6 72.4 75.9 79.4 81.9 84.0 90.6 95.9 60
I-V 8.8 18.7 28.2 37.3 46.6 53.2 58.7 62.8 66.3 68.4 70.1 74.6 77.4 81.2 87.0 84.6 Mean of
Means
1. Two fish from section Ill were 65.6 and 68.2 em and aged 9+ and 11+ respectively. ...... ......
w
Appendix V(ii). Growth of lake whitefish. Coregonus clupeaformis~n five sections of the Lower Churchill River. Labrador.
June-August. 1975-76.
River Mean calculated fork length (em} atage-No. of
section 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 fish
11.4 15.6 18.4 20.6 22.2 25.0 26.2 28.4 30.1 39.1 150
II a 11.4 15.2 18.3 21.4 24.3 27.1 29.3 31.2 33.4 35.1 36.4 37.8 39.3 140
III 12.8 19.2 I 23.3 26.3 29.1 31.4 33.1 34.3 35.8 35.4 36.3 36.8 36.9 104
' IV 15.8 19.5 23.4 26.4 28.1 30.6 32.1 33.9 35.1 36.4 38.0 39.1 54
v 13.1 17.7 21.4 24.5 27.1 29.4 31.3 33.1 34.2 35.9 37.6 41.4 43.1 52.3 53.1 54.1 55.6 152
I-V 12.9 17.4 21.0 23.8 26.2 28.7 30.4 32.2 33.7 36.4 37.1 38.8 39.8 52.3 53.1 54.1 55.6 -
Mean of
means __. __,
-+:>
a. Fish of ages 14-20 were deleted due to insufficient sample size.
Appendix V(iii). Growth of longnose suckers, Catostomus catostomus, in five sections of the Lower Churchill River, Labrador,
June-August, 1975-76.
River Mean calculated fork length (em} at age -No. of
section 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 fish
6.4 10.4 13.7 17.0 19.9 22.4 25.0 27.5 29.3 30.7 33.5 35.4 38.8 41.8 148
II 4.7 7.7 11.0 14.4 17.2 20.8 23.7 26.8 30.2 32.7 34.7 37 .l 38.7 39.7 53
III 5.4 8.3\ 11.4 14.8 17.9 21.0 23.8 26.5 29.0 30.8 33.5 35.3 37.5 38.9 43.9 189
IVa 7.0 10.1 13.2 15.9 18.7 21.5 24.1 26.5 29,0 30.8 32.2 34.7 3f.3 38.6 40.3 46.6 97.
v 3.0 5.4 8.3 11.3 14.5 17.8 21.7 24.5 27.5 30.5 33.2 35.1 38.2 38.9 148
1-V 5.3 8.4 11.5 Mean of 14.7 17.6 20.7 23.7 26.4 29.0 3l.l 33.4 35.5 37.9 39.6 42.1 46.6 __.
means
<.n
a. cne fish in its 19th year was not included.
Appendix V(iv). Growth of white suckers, Catostomus commersoni, in five sections of the Lower Churchill River, Labrador,
June-August, 1975-76.
No.
River Mean calculated fork length (em} at age -of
section 2 3 4 5 6 7 8 9 10 ll 12 13 14 15 16 17 fish
5.7 9.2 13.5 17.6 21.0 23.7 25.8 28.1 29.8 30.2 31.8 182
II 9.5 11.6 14.6 18.2 21.7 25.1 29.9 33.1 35.2 37.3 38.7 39 .. 7 41.2 150
III 8.8 13.2 \17.9 22.2 26.5 30.8 33.6 36.7 40.5 42.6 43.0 20 ..
IV 11.8 12.7 14.4 17.2 '20.0 22.8 26.5 29.3 32.1 34.9 36.6 38.6 41.1 43.0 46.5 48.3 49.5 102
va 9.6 11.6 14.5 17.9 21.4 25.2 28.7 31.5 34.3 37.2 39.2 41.0 42.9 44.4 44.6 46.1 155
I-V
Mean of 9.1 11.7 15.0 18.6 22.1 25.5 28.9 31.7 34.4 36.4 37.9 39.8 41.7 43.7 45.6 47.2 49.5 -
means _,
0"1
a. One fish in its 19th year was not included.
Appendix V(v). Growth of brook trout,Salvelinus fontinalis, in five sections of the Lower Churchill River, Labrador,
June-August, 1975-76.
River Mean calculated fork length (em} at age -
section 2 3 4 5 6 7 8 9 10 ~1 12 13 14 15
10.1 14.2 17.0 21.2 24.9 30.8
lla 19.2 23.4 38.2
1
III 7.7 15.5 23.4 30.8 35.3 39.3
IVa 38.2 39.0
v 5.8 12.5 20.2 26.9 34.9 43.5
I,III,and V 7 9 Mean of • 14.1 20.2 26.3 31.7 37.9
means
a. Lengths are lengths at capture.
b. Includes 41 angled fish.
No. of
16 fish
37
3
183b
5
87
...... ......
"-J
Appendix V(vi). Growth of burbot.lota lota in five sections of the lower Churchill River. labrador. June-August. 1975-76.
River Mean total length {em} at ca~ture of fish in age grou~ -No. of
section 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 fish
34.6 36.6 51.2 48.5 7
II 30.5 44.1 48.7 49.4 54.6 52.0 13
III ,23.1 33.9 33.2 46.4 46.8 51.0 56.0 42.5 53.5 18
\
IV 40.1 34.7 43.2 46.5 55.9 56.1 68.7 23
v 22.5 29.7 29.7 30.5 32.5 43.8 43.8 53.8 56.1 60.3 68.9 24
1.-V.
Mean of 22.8 34.6 32.5 39.4 44.5 48.2 50.2 53.9 51.6 60.3 68.8 53.5
means ...... ......
(X)
J
Appendix V(vii).Growth of lake trout, Salvelinus namaycush in three sections of the Lower Churchill River, Labrador,
June-August, 1975-76.
River
sec'tion 2 3 4
Mean fork length (em) at capture of fish in age group -
14 15 16
No. of
fish
Appendix V(viii). Growth of ouananiche, Salmo salar in one section of the Lower Churchill River, Labrador, June-August.
1975-76. ----
River Mean calculated fork length (em} at age -
section 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
lll. ab 24.1 43.2
IV.c 12.4 17.2 22.8 28.9 35.1 42.1 46.8 49.8 52.2
v.a 27.8 39.9 43.3 44.8
a. Lengths are lengths at capture.
b. Includes one angled fish.
c. Includes five angled fish.
No. of
fish
3
22
ll
......
N
0
Appendix V(ix). Growth of round whitefish. Prosopium cylindraceum.in five section of the Lower Churchill River. Labrador.
June-August. 1975-76.
River Mean calculated fork length {em} at age -No. of
section 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 fish
la 21.5 20.5 23.7 23.2 14
II a 32.9 34.5 40.4 3
III 11.4 16.1 ·20.0 23.1 25.4 27.4 29.4 30.9 31.7 34.4 34.2 36.0 105 ..
IVa 20.5 26.6 26.5 3
v 5.7 14.0 17.7 19.1 22.1 22.9 27.4 27.4 30
III and V 8.6 15.1 18.9 21.1 23.8 25.2 28.4 29.2 31.7 34.4 34.2 36.0 mean of
means _.
N _.
a. Lengths are lengths at capture.
123
Appendix VI
Sex ratios of fishes from the Lower Churchill River
Appendix VI. Sex ratios (number of males per female) of fishes from the Lower Churchill River,
June-August, 1975-76.
Species
Northern Pike
Lake Whitefish
Longnose Sucker
~~hi te Sucker
Brook Trout
River
Section
I
II
III
IV
v
I-V
I
II
III
IV
v
I-V
I
II
III
IV
v
I-V
I
II
III
IV
v
I-V
I
II
III
IV
v
I-V
No. Of
Fish
Examined
55
130
2
18
60
265
294
145
119
58
221
837
289
55
261
171
776
239
171
20
113
543
35
3
569
5
87
699
Sex
Ratio
1.62
0.88
a
1.25
1.61b
1.19
0.57
1. 38
0.95
1.15
1. 38b
0.95
0.24
0.4!>
0.51
0.75
0~43d
1.19
0.86
1.22
0.88
c
1. 01 b
0.84
2.00
1.10
0.67
0.98b
1.07
.......
N
U1
Appendix VI -Continued.
Species River No. Of Sex
Section Fish Ratio
Examined
Burbot I .6 5.00
II 13 0.18
III 18 1. 57
IV 23 0.44
v 24 0.60b
I-V 84 0.68
Lake Trout III 3 0.50
IV 8 0.60
v 4 3.00b
III -V 15 0.88 __.
N
Ouananiche III 3 0.50 m
IV 22 0.69
v 11 1. 75b
III -V 36 0.90
Round Whitefish I 1]. 0.89
II 3 0.50
III 116 0.90
IV 3 0.00
v 30 3.29b
I-V 169 1.06
Lake Chub III 3 0.00
Rainbow Smelt .I 2 0.00
a. Ap males.
b. x ~ 3.84 indicates no departure from 1:1 sex ratio.
c. N~t determined. ·
d. x > 3.84 indicates departure from 1:1 sex ratio.
127
Appendix VII
Length at maturity of fishes from the Lower Churchill River
(i) Northern pike
(ii) Lake whitefish and round whitefish
(iii) White suckers, longnose suckers and
brook trout
(iv) Burbot and ouananiche
(v) Lake trout
Appendix VII (i). Length at maturity of northern pike from the Lower Churchill River, June-August,
1975-76.
Fork Number %
Length (em) Examined Mature
20.0-24.9 9 0.0
25.0-29 .. 9 11 0.0
30.0-35 .. 9 6 16.7
35.0-39.9 4 50.0
40.0-44.9 7 71.4
45.0-49.9 16 100.0
50.0-54.9 16 87.5
55.0-59.9 37 100.0
60.0-64.9 59 100.0
65.0-69.9 46 100.0
70.0-74.9 20 100.0
75.0-79.9 7 100.0
80.0-84.9 8 1 oo.o
85.0-89.9 10 100.0
90.0-94.9 4 100.0
95.0-99.9 2 100.0
100.0-104.9 3 100.0
105.0-109.9
Total 265 88.3
N
U)
Appendix VII (ii). Length at maturity of lake whitefish and round whitefish from the Lower Churchill
River, June-August, 1975-76. ·
Lake Whitefish Round ~~hitefish
Fork Number % Number %
Length (em) Examined Mature Examined ~·1ature
12.0-13.9
14.0-15.9 5 40.0
16.0-17.9 2/ 25.9 1 100.0 18.0-19.9 52 38.5 28 64.3 20.0-21.9 38 57.9 33 72.3 22.0-23.9 51 76.5 25 88.0 24.0-25.9 41 92.7 23 91.3 26.0-27.9 32 93.8 14 92.9 28.0-29.9 17 52.9 11 100.0 30.0-31.9 21 76.2 3 100.0 32.0-33.9 45 91.1 14 85.·7 __,
w 34.0-35.9 107 95.3 8 100.0 0
36.0-37.9 143 97.2 6 100.0 38.0-39.9 91 98.9 1 100.0 40.0-41.9 37 92.3 1 100.0 42.0-43.9 18 100.0 1 100.0 44.0-45 .. 9 6 100.0
46.0-47.9 2 100.0
48.0-49.9 1 100.0
50.0-51.9 3 100.0
52.0-53.9
Totals 737 84.3 169 84.0
Appendix VII (iii). Length at maturity of white suckers, longnose suckers, and brook trout from the Lower
Churchill River, June-'August, 1975-76.
White suckers Longnose suckers Brook trout
Fork Number % Number % Number %
Length (em) Examined Mature Examined Mature Examined Mature
10.0-11.9
12.0-13.9 2 50.0
14.0-15 .. 9 2 0 .. 0 4 0.0 8 50.0
16.0-17.9 46 32.6 46 17.4 27 63.0
18.0-19.9 32 25.0 40 27.5 42 78.6
20.0-21.9 64 43.8 33 81.8 16 87.5
22.0-23.9 71 66.2 80 92.5 32 81.3
24.0-25.9 38 73.) 63 92.1 29 93.1
26.0-27.9 11 90.9 34 100.0 38 80.0
28.0-29.9 13 92.3 19 100.0 35 91.4
30.0-31.9 47 1 00 .. 0 68 100.0 59 100.0
32.0-33.9 59 100.0 79 100.0 70 94.3
34.0-35.9 41 100.0 89 100.0 77 98.7
36.0-37.9 25 100.0 60 100.0 84 97.6
38.0-39.9 27 100.0 42 100.0 71 95.8
40.0-41.9 31 100.0 16 100.0 46 97.8
42.0-43.9 24 95.8 9 ]00.0 42 100.0
44.0-45.9 13 100.0 7 100.0 14 92.9
46.0-47.9 3 100.0 3 100.0 1 100.0
48.0-49.9 2 100.0 5 100.0 2 100.0
50.0-51.9 1 100.0
52.0-53.9 1 100.0 1 100.0
54.0-55.9
Total 550 76.4 698 87.4 695 91.9
__,
w __,
Appendix VII (iv). Length at maturity of burbot and ouananiche from the Lower Churchill River,
June-August, 1975-76.
Burbot Ouananiche
Number % Number %
Length (cm)a Examined Mature Examined t·1ature
16.0-17.9 l 0.0
18.0-19.9
20.0-21.9
22.0-23.9 5 40.0
24.0-25.9 1 l 00.0
26.0-27.9 1 0.0
28.0-29.9 5 20.0
30.0-31.9 4 25.0
32.0-33.9 4 75.0
34.0-35.9 1 100.0
36.0-37.9 1 100.0
38.0-39.9 3 100.0 3 66.7
40.0-41.9 4 100.0 4 50.0
42.0-43.9 8 .lQO.O 4 100.0
44.0-45.9 7 100.0 4 75.0
46.0-47.9 9 100.0 2 100.0
48.0-49.9 4 100.0 2 100.0
50.0-51.9 3 100.0 2 l 00.0
52.0-53.9 4 100.0 3 100.0
54.0-55.9 3 100.0 1 100.0
56.0-57.9 5 100.0 2 100.0
58.0-59.9 2 100.0 1 100.0
60.0-61.9 3 100.0 1 100.0
62.0-63.9 l 100.0 1 l 00.0
64.0-65.9 1 100.0 1 100.0
66.0-67.9 1 100.0
68.0-69.9 2 100.0
70.0-71.9
Totals 79 86.1 35 02.9
a. Lengths are total lengths for burbQt and fork lengths for ouananiche.
w
N
Appendix VII (v). Length at maturity of lake trout from the Lower Churchill River, June-August,
1975-76.
Fork Number %
Length (em) Examined Mature
30.0-39.9 2 50.0
40.0-49.9 3 100.0
50.0-59.9 4 1 00. (j
60.0-69.9 3 100.0
70.0-79.9 1 100.0
80.0-89.9 1 100.0
90.0-99.9 1 100.0
100.0-109.9
Total 15 93.3 __,
w w
135
Appendix VII I
Catch statistics of fishes from the Lower Churchill River.
(i) Northern pike
{ii) Lake whitefish
(iii) Longnose suckers
(iv) White suckers
(v) Brook trout
(vi) Burbot
(vii) Lake trout
(viii) Ouananiche
(ix) Round whitefish
Appendix VIII (i). Catch statistics of northern pi,ke from the Lower Churchill River,
Labrador, June-August, 1975-76.
Mesh No. of No. of Mean Total Mean
River size net No. of fish per length weight weight
Weight
per net
section {ern) nights a fish caught net night {em) (kg) (kg) night(kg)
I b 3.8-12.7 150 55 (100%) 0.4 62.2 11 8 . 3 (1 00% ) 2.15 0.79
II 3.8 44 36 (27.1%) 0.8 46.2 44.2 ,("18.0%) 1.30 1..01
5.1 44 29 (21.8%) 0.7 54.4 55.1 (22.4%) 1.90 1.25
7.6 44 34 (25.6%) 0.8 55.2 47.6 (19.3%) 1.40 1.08
10.2 44 29 (21.8%) 0.7 69.3 81.2 (33.0%) 2.80 1.85
12.7 44 5 ( 3.8%) 0.1 73.9 17.9 ( 7.3%) 3.60 0.41
3.8-12.7 220 133 (100%) 0.6 56.4 246; 0 {l 00%) 1.85 1.12
III 12.7 21 1 {100%) 0.1 68.2 2.3 (100%) 2. 31 0.11
3.8-12.7 113 1 (100%) <0.1 68.2 ' 2.3 (l 00%) 2.31 0.02
IV 3.8 12 3 (18.8%) 0.3 72.5 10.0 {26.7%) 3.30 0.83
5.1 12 2 (12.5%) 0.2 52.9 3.3 ( 8.8%) 1.60 0.28
7.6 12 6 (37.5%) 0.5 65.4 13.3 (35.6%) 2.20 1 .11
10.2 12 5 ( 31. 3%) 0.4 66.0 10.8 (28.9%) 2.20 0.90
12.7 12 o (o.a%J 0.0 o.a (O.O%) 0.00
3.8-12.7 60 16 (1 00%) 0.3 65.4 3 7 . 4 .( 1 00% ) 2. 34 0.62
v 3.U 28 3 (5.0%) 0.1 72.7 9.9 (6.8%) 3.28 0.35
5. 1 '28 5 (8.3%) 0.2 65.0 112 . 9 ( 8. 9%) 2.58 ·0.46
7.6 30 17 (28. 3%) 0.6 62.3 35.5 (24.4%) 1. 97 1.18
10.2 30 30 (50.0%) 1.0 64.5 67.2 (46.1%) 2.24 2.24
12.7 30 5 (8.3%} 0.2 82.1 20.3 (13.9%) 4.07 0.68
3.8-12.7 146 60 (100%) 0.4 65.8 145.8 (100%) 2.43 1.00
I-V 3.8-12.7 689 265 0.4 63.6 549.8 2.08 0.80
a. A net night is one 47 metre gi1lnet fished for a 24 hour period.
b. Catch data by mesh size not available~
Mean
age
(yt')
7.5
5.6
6.9
7.4
9.5
10.4
7.4
11.0 ~ 11.0 w ......
10.7
7.0
8.3
8.0
8.5
7.7
7.2
6.9
7.1
10.4
8.2
8.5
Appendix VIII (ii). Catch statistics of lake whitefish from the Lower Churchill River,
Labrador, June-August, 1975-76.
Mesh No. of No. of Mean Total Mean
River size net No. of fish per length weight weight
Weight
per net
section (ern) nightsa fish caught net night (ern) (kg) (kg) night{kg)
I b 3.8-12.7 150 294 (100%) 2.0 22.7 127.1 (100%) 0.43 0.85
II 3.8 44 27 (18.6%) 0.6 22.6 5.5 (7.0%) 0.20 0.13
5.1 44 27 (18.6%) 0.6 27.8 8.6 (11.0%) 0.32 0.20
7.6 44 62 (42.8%} 1.4 35.8 40.6 (51.9%) 0.67 0.92
10.2 44 24 (16.6%) 0.6 37.7 19.0 (24. 3%). 0. 79 0.43
12.7 44 5 (3.5%) 0.1 39.2 4.5 (5.8%} 0.89 0.10
3.8-12.7 220 145 (100%) 0.7 32.3 78.2 (100%) 0.54 0.36
III 3.8 23 1 (0.8%) <0.1 25.0 0.2 (0.3%) 0.17 0.01
5.1 23 8 (6.7%) 0.1 31.6 3.9 (5.0%) 0.49 0.17
7.6 23 49 (41.2%) 0.4 35.3 29.6 (37.8%) 0.60 1.27
10.2 23 61 (51.3%) 0.5 37.4 44.6 (57.0%) 0.73 1. 94
12.7 21 0 (0.0%) 0.0 0.0 (0.0%) 0.00
3.8-12.7 113 119 (1 00%) 1.1 36.0 78.3 (100%) 0.66 0.69
IV 3.8 12 4 (6 .. 8%) 0.3 40.2 3.2 (8.1%) 0.81 0.27
5. l 12 9 (15.5%) 0.8 32.5 4.5 (11.5%) 0.50 0.38
7.6 12 25 (43.1 %) 2.1 36.4 15.6 (39.7%) 0.62 1.30
10.2 12 20 (34.5?~) 1.7 39.0 16.0 (40.7%) 0.80 l. 33
12.7 12 0 (0.0%) 0.0 0.0 (0.0%) 0.00
3.8-12.7 60 58 (100%) 1.0 37.0 39.3 {100%) 0.68 0.66
v 3.8 28 8 (3.6%) 0.3 27.0 2. 7 (1. 8%} 0.34 0.10
5. l 28 30 (13.6%) 1.1 32.5 15.4 (10.5%) 0.51 0.55
7.6 30 104 (47 .1 %) 3.5 36.7 69.9 (47.8%) 0.67 2.33
10.2 30 73 (33.0%) 2.4 37 .l 52.2 (35.7%) 0.72 1. 74
12.7 30 6 ( 2. 3%) 0.2 40.9 5.9 (4.0%) 0.99 0.20
3.8-12.7 146 221 (1 00%} 1.5 36.0 146. l ( 1 00%) 0.66 1.00
I-V 3.8-12.7 689 837 1.2 32.8 469.0 0.56 0.68
a. A net night is one 47 metre gi 11 net fished for a 24 hour period.
b. Catch data mesh size not available.
Mean
age
(yr)
4.3
3.8
5.4
8.8
10.0
11.2
7.5
4.0
6.3
7.5
8.3 1-' w
(X)
7.8
9.0
6.0
8.2
8.5
8.0
4.7
5.5
7.6
7.6
9.5
7.3
7.0
Appendix VIII (iii). Catch statistics of longnose suckers from the Lower Churchill River, Labrador,
June-August, 1975-76.
Mesh No. of No. of Mean Total f4ean Weight
River size net No. of fish per length weight weight per net
Section (em) nights a fish caught net night (em) (kg.) (kg) night (kg)
I b 3.8-12.7 150 289 (100%} 1.9 25.5 70.4 (100%} 0.31 0.47
II 3.8 44 15 (27.3%} 0.3 18.8 1.2 (5.6%) 0.08 0.03
5. 1 44 19 (34.6%) 0.4 29.2 3.6 (17.0%) 0.19 0.08
7.6 44 14 (29.9%} 0.3 35.7 8. 1 (.38. 4%) 0.58 0.18
10.2 44 6 (10.9%} 0.1 43.7 6. 6 (31. 3%} 1.10 0.15
12.7 44 1 (1.8%} 0.1 49.1 1. 6 ( 7. 6%} 1.60 0.04
3.8-12.7 220 55 (1 00%) 0.3 30.0 21.1 (100%) 0.38 0.10
III 3.8 23 61 (22.8%) 2.7 19.5 5.3 (5.4%) 0.09 0.23
5. 1 23 63 (23.5%} 2.7 27.3 14.9 (15.2%} 0.24 0.65
7.6 23 121 (45. 2%} 5.3 34.8 60.4 (61."6%} 0.50 2.63
10.2 23 22 (8.2%) 1.0 39.6 17.1 (17.5%) 0.78 0.74
12.7 21 1 (0. 4%) 0.1 33.4 0.4 (0.4%) 0.44 0.02
3.8-12.7 113 368 (1 00%) 2.4 30.1 98.0 (100%) 0.37 0.87
IV 3.8 12 1 (0.6%) 0.1 46.0 L2 (1.4%) 1.20 0.10
5. l 12 13 ( 7. 6%) 1.1 27.4 3.1 (3.6%) 0.20 0.26
7.6 12 142 {83.0%} 11.8 34.7 69.5 (80.7%) 0.50 5.79
10.2 12 13 (7.6%} l.l 40.9 11.3 (13.1%) 0.90 0.,94
12.7 12 1 (0.6%) 0.1 49.5 1. 0 ( l. 2%) 0.10 0.08
3.8-12.7 60 170 (1 00%} 2.0 34.8 86.1 (,100%) 0.51 1.44
v 3.8 28 118 (28.9%) 4.2 18.3 8.3 (6.6%) 0.07 0.30
5. 1 28 129 ( 31. 5%) 4.6 27.0 32.5 (25.8%) 0.25 1.16
7.6 30 155 (37.9%) 5.2 35.1 78.6 (62.4%) 0. 51 2.62
10.2 30 7 (1.7%) 0.2 42.5 6.4 (5.1%} 0.92 0.21
12.7 30 0 (0.0%} 0.0 0.0 (0.0%} 0.00
3.8-12.7 146 409 (100%) 2.8 27.8 125.9 (100%} 0. 31 0.86
I-V 3.8-12.7 689 1191 1.7 29.6 401.5 0.34 0.58
a. A net night is one 47 metre gillnet fished for a 24 hour period.
b. Catch data by mesh size not available.
Mean
age
(yr}
6.9
5.0
7.2
11.0
13.0
14.0
8.3
5.3
7.7
10.8 I-' 12.5 w
1.0 12.0
9.0
5.0
9.2
12.5
13.7
16.0
12.3
4.4
7.6
10.6
Not available
7.5
8.8
Appendix VIII (iv). Catch statistics of white suckers from the Lower Churchill River, Labrador
June-August, 1975-76.
Mesh No. of No. of Mean Total He an Weight Mean
River size net No. of fish per length weight weight per net age
Section (an) nights a fish caught net night (em) (kg) (kg) night (kg) (yr)
I b 3.8-12.7 150 252 (100%) 1.7 25.6 64.9 (100%) 0.26 0.43 6.0
II 3.8 44 29 (17.0%} 0.7 17.7 2.0 (2.2%) 0.07 0.05 3.7 5.1 44 40 (23.4%) 0.9 29.1 10.0 (11.1%) 0.25 0.23 5.3 7.6 44 72 (42. 1%) 1.6 35.0 48.2 (53.3%) 0.67 1.10 7. 1 10.2 44 30 (17.9%) 0.7 40.2 30.2 (33.4%) 1.00 0.69 9.6 12.7 44 0 (0.0%) 0.0 0.0 (0.0%) 0.00 3.3-12.7 220 171 ( 1 00%) 0.8 31.6 90.4 (1 00%) 0.53 0.41 6.5
III 3.3 23 3 (15.0%) 0.1 21.4 0.3 (2.4%) 0.10 0.01 3.7 5.1 23 1 ( 5. 0%) <0.1 24.5 0.2 (1.7%) 0.15 0.01 4.0 1-' 7.6 23 11 (55.0%) 0.5 35.8 7.1 (58.7%) 0.64 0.31 7.1 -"" 0 10.2 23 5 (25.0%) 0.2. 39.0 4.5 (37.2%) 0.90 0.20 8.2 12.7 21 0 (0.0%) 0.0 0.0 (0.0%) ";" 0.00 3.3-12.7-113 20 (100%) 0.2 33.9 12. 1 (1 00%) 0.61 0.11 6.7
IV 3.8 12 9 (8.0%) 0.8 24.6 2.7 (4.2%) 0.30 0.22 6.0 5.1 12 39 (8.0%) 3.3 23.5 7.2 (11.4%) 0.20 0.60 6.7 7.6 12 37 (32.7%) 3.1 37.0 26.0 (41.0%) 0.70 2.17 10.4 10.2 12 27 (23.9%) 2.3 41.9 26.6 (42.0%) 1.00 . 2.22 12.0 12.7 12 1 (0. 9%) 0.1 49.7 0.9 (1.4%) 0.93 0.08 3.8-12.7 60 113 (100%) 1. 9, 32.6 63.4 (100%) 0.56 1.06 9.1
v 3.8 28 10 (6.5%) 0.4 18.9 0.8 (0.7%) 0.08 0.03 4.3 5.1 28 22 (14.2%) 0.8 26.9 6.3 (5.1%) 0.29 0.23 6.1 7.6 30 43 (27.7%) 1.4 37.1 31.4 (25.6%). 0.73 1.05 9.7 10.2 30 76 (49.0%) 2.5 42.2 78.2 (63.8%) 1.03 2.61 12.0 12.7 30 4 (2.6%) 0. 1 47.4 5.9 (4.8%) 1.48 0.20 15.0 3.8-12.7 . 146 155 (100%) 1.1 37.2 122.6 (100%) 0.79 0.84 9.4
I-V 3.8-12.7 689 711 1.0 32.2 353.4-0.50 0. 51 7.5
a. A net night is one 47 metre gil1net fished for a 24 hour period.
b. Catch data by mesh size not available.
Appendix VIII (v). Catch statistics of brook trout from the Lower Churchill River, Labrador,
June-August., 1975-76.
Mesh No. of No. of Mean Total f4ean Weight Mean
River size net No. of fish per length weight weight per net age
Section (em.) nightsa fish caught net night (em) (kg) (kg) night (kg) {yr)
I b 3.8-12.7 150 38 {100%) 0.3 22.8 5.0 (100%) 0.13 0.03 3.8
II 3.8 44 1 (33.3%) 0.1 19.2 0.1 (9.1%) 0.09 0. 01 2.0
5.1 44 1 {33.3%). 0.1 23.4 0.2 (18. 2%) 0.15 0.01 3.0
10.2 44 1 (33. 3%) 0.1 38.2 0.8 (72.7%) 0.80 0.02 4.0
3.8-12.7 220 3 (100%) 0.1 26.9 1.1 {100%) 0.37 0.01 3.0
II I c 3.8 23 74 (16.6%) 3.2 20.6 9.0 (4.3%) 0.12 0.39 2.4
5.1 23 61 (·13.7%) 2.7 28.1 16.2 ~7.7%) 0.27 0.70 3.2
7.6 23 233 {52.2%) 10.1 35.1 123.2 58.8%) 0.53 5.36 3.9
10.2 23 76 (17.0%) 3.3 40.3 60.7 (29.0%) 0.80 2.64 4.6
12.7 21 2 (0.1%) 0.1 26.7 0.4 (0.2%) 0.21 0.02 3.0
3.8-12.7 113 446 (100%) 4.0 32.6 209.5 (100%·) 0.47 1.85 3.7
IV 3.8 12 1 (20.0%) 0.1 38.8 0.7 ( 18. 9%) 0.74 0.06 4.0
5. 1 12 2 (40.0%) 0.2 39.0 l. 7 (50.0%) 0.85 0.14 4.5
7.6 12 2 (40.0%) 0.2 38.0 1. 3 ( 35. 1%) 0.63 0.11 4.5
3.8-12.7 60 5 (1 00%) 0.1 38.6 3. 7 (TOO%) 0.74 0.06 4.4
v 3.8. 28 8 (9.2%) 0.3 20~4 0. 7 ( 1. 7%) 0.09 0.03 2.4
5.1 28 23 (26.4%) 0.8 25.6 4.5 (lO.G%) 0.19 0.16 2.8
7.6 30 35 (40.2%) 1.2 34.5 13.1 (42.8%) 0.52 0.60 4.0
10.2 30 16 (18.4%) 0.5 39.7, 13.8 (32.6%) 0.86 0.46 4.5
12.7 30 5 (5.7%) 0.2 41.1 5.2 (12.3%) 1 .. 04 0.17 4.6
3.8-12.7 146 87 (100%) 0.6 32.2 42.3 (100%) 0.49 0.29 3.7
I-V 3.8-12.7 689 579 0.8 30.6 261.6 0.45 0.38 3.7
a. A net night is one 47 metre gillnet fished for a 24 hour period.
b. Catch data by mesh size not available.
c. Thirteen man hours of angling yielded 123 fish weighing 57.5 kg with a mean length of 34.0 em and a mean age
of 3.8 yrs.
1-' +:>
1-'
Appendix VIII (vi). Catch statistics of burbot from the Lower Churchill River, Labrador,
June-August, 1975-76.
Mesh No. of No. of Mean Total Mean Weight Mean
River size net No. of fish per length weight weight per net age
section (em) nights a fish caught net night (em) (kg) (kg) night(kg) (yr)
?-3.8-12.7 150 7 (l 00%) 0.1 41.5 4.3 (100%) 0.61 0.03 6.4
II 5.1 44 1 (7.7%) <0. 1 30.5 0.2 (l.C%~ 0.16 0. 01 5.0
7.6 44 5 (38.5%) 0.1 45.5 3.1 (.~3.4% 0.62 0.07 7.4
10.2 44 7 (53.9%) 0.2 54.1 7.6 (69.7%) 1.10 0.17 8.6
3.8-12.7 220 13 (1 00%) 0.1 49.0 10.9 (100%) 0.84 0.05 7.9
III 5. l 23 2 (11.1%) 0.1 30.8 0.4 (4.3%) 0.17 0.02 4.5
7.6 23 12 (66.7%) 0.5 43.9 6.5 (69.~%) 0.55 0.2U 6.5 ._.
10.2 23 2 (11.1%) 0. l 54.7 2.3 (24. 7~~) 0.11 0.10 11.5 .J::>
N
12.7 21 2 (11.1%) 0.1 23.6 0.1 (1.1%) 0.07 0.01 3.0
3.8-12.7 113 18 (100%) 0.2 41.4 9.3 (100%) 0.52 0.08 6.4
IV 5.1 12 3 (13.0%) 0.3 32.1 0.5 (2.8%) 0.10 0.04 5.0
7.6 12 13 (56;5~.:) 1.1 43.9 6.5 (36.5%) 0.50 0.54 7.5
10.2 12 4 (1/.4:.,) 0.3 56.8 4.5 (25.3%) 1.10 0.313 10.3
12.7 12 3. (13.0%) 0.3 65.8 6.3 (35.4%) 2.10 0.53 11.0
3.8-12.7 60 23 (100%) 0.4 47.5 17,8 (100%) 0. 77 0.30 8.1
v 3.8 28 2 (8. 3%) 0.1 22.5 0.1 (0.6%) 0.05 <0.01 3.0
5.1 28 7 (29.2%) 0.3 30.5 1.2 (6.8%) 0.17 0.04 5.3
7.6 30 3 (12.5%) 0.1 43.8 1.5 (8.5%) 0.50 0.05 8.7
10.2 30 . 9. (37.5%) 0.3 50.9 9.1 (51.7%) 1.01 0.30 10.4
12.7 30 3 (12.5%) 0.1 65.5 5.7 (32.4%) 1.89 0.19 12.0
3.3-12.7 146 24 (100%) 0.2 43.5 17.6 ( 100%) 0.73 0.12 8.3
I -V 3.8-12.7 689 85 0.1 44.6 59.9 0.70 0.09 7.4
a. A net night is one 47 metre gil1net fished for a 24 hour period.
b. Catch data by mesh size not available.
Appendix VIII (vii). Catch statistics of lake trout from the lm-rer Churchill River, labrador,
June-August, 1975-76.
Mesh No. of No. of Mean Total f4ean Weight
River size net No. of fish per length weight weight per net
Section (em") nightsa fish caught net night (em) {kg) (kg) night (kg)
III 10.2 23 3 (100%) 0.1 42.7 2.7 (1 00%) 0.91 0.12
3.8-12.7 113 3 (100%) <0.1 . 42.7 2.7 ( 1 00%) 0.91 0.02
IV 10.2 12 6 (75.0%) 0.5 59.9 20.1 (72.3%) 3.35 1.68
12.7 12 2 ~25.0%) 0.2 61.8 7.7 {27.7%) 3.85 0.64
3.8-12.7 60 8 100%) 0.1 60.4 27. 8 (TOO%') 3.60 0.4.6
v 3.8 28 1 (25.0%) <0.1 92.0 10.4 (48:8%)10.40 0.37
5. 1 28 1 (25.0%) <0. 1 37.4 0.8 (3.8%) 0.80 0.03
7.6 30 1 (25.0%) <0. 1 56.5 2.1 (9. 9%.) 2.13 0.07
10.2 30 0 (0.0%) <0.0 o.o (o~o%) 0.00
12.7 30 1 (25.0%) <0. 1 84.3 8.0 (37.6%) 7.95 0.27
3.8-12.7 146 4 (100%) <0.1 67. 6' 21.3 ( 100%) 5.30 0. 1,5
I-V 3.8-12.7 689 15 <0. 1. 57.0 51.8 3.45 0.08
a. A net night is one metre gil1net fished for a 24 hour period.
Mean
age
(yr)
7.0
7.0
12.3
12.0
12.2
15.0 1-' 7.0 .J::> w 11.0
14.0
11.8
10.3
Appendix VIII (viii). Catch statistics of ouananiche from the Lower Churchill River, Labrador,
June-August, 1975-76.
Mesh No. of No. of Mean Total Mean Weight
River size net No. of fish per length weight weight per net
section (em) nights a fish caught net night (em) (kg) (kg) night( kg)
I II b 5.1 23 1 (50.0%) <0. 1 24.1 0.2 p6.7%) 0.15 0.01
10.2 23 1 (50.0%) <0. 1 44.6 1.0 83.3%) 0.99 0.04
3.8-12.7 113 2 (1 00%) <0. 1 34.4 1. 2 (1 00%) 0.60 0.01
IV c 3.8 12 8 (47.1%) 0.7 44.8 8.5 (37.0%) 1.07 0.71
5.1 12 3 (17.7%) 0.3 56.2 5.3 (23.0%) 1. 78 0.44
7.6 12 1 (5.9%) 0.1 42.5 1.0 (4.4%) 1.00 0.08
10.2 12 3 (17.7%) 0.3 51.6 5.1 (22. 2%) 1.69 0.43
12.7 12 2 (11.8%) 0.2 50.3 3.0 (13.0%) 1.52 0.25
3.8-12.7 60 17 (100%) 0.3 48.6 23.0 (100%) 1.35 0.38
v 3.8 28 1 (9.1%) <0. 1 45.8 1.2 (10.8%) 1.15 0.04
5.1 28 3 (27.3%) 0.1 37.2 2.6 (23.4%) 0.87 0.09
7.6 30 3 (27.3%) 0.1 45.6 3.5 (31.5%) l. 18 0.12
10.2 30 4 (36.4%) 0.1 42.7 3.8 (34.2%) 0.96 0.13
3.8-12.7 146 11 (100%) 0.1 42.3 11.1 (1 00%) 1.01 0.08
I-V 3.8-12.7 689 30 <0. 1 41.7 35.3 1.18 0.05
a. A net night is one 47 metre gi11net fis~~1 for a 24 hour period~
b. One 41.1cm, 0.76 kg, age-group 7 fish wa~ ana led.
c. Five fish averaging 48.8cm,' 1.20 kg, and 6.4 year old were angled.
Mean
age
(yr)
5.0
7.0
6.0
5.9
7.0
7.0
7.0 .......
8.0 ..j::.
..j::.
6.6
7.0
5.3
6.3
6.5
6.2
6.2
Appendix VIII (ix). Catch statistics of round whitefish from the Lower Churchill River, Labrador,
June-August, 1975-76.
Mesh No. of No. of Mean Total Mean Weight
River size net No. of fish per length weight weight per net
section (em) nights a fish caught net night (em) (kg) (kg) night( kg)
I b 3.8-12.7 150 17 ( 100%) 0.1 22.1 1. 7 (1 00%) 0.10 0.01
II 5.1 44 1 (33.3%) <0.1 40.4 0.8 (42.1%) 0.80 0.02
7.6 44 1 (33.3%) <0.1 32.9 0.5 (26.3%) OA7 0.01
10.2 44 1 (33.3%) <0 .. 1 34.5 0.6 (31.5%) 0.63 0.01
3.8-12.7 220 3 ( 1 00%) <0. 1 35.9 1. 9 (100%) 0.63 0.01
III 3.8 23 47 (40.5%) 2.0 20.9 4.3 (17.5%) 0.09 0.19
5.1 . 23 46 (39.7%) 2.0 26.8 8.6 (35.0%) 0.19 0.37
7.6 23 20 (17.2%) 0.9 35.3 9.9 (40.2%) 0.49 0.43
10.2 23 2 (1. 7%) 0.1 36.9 1.5 (6.1%) 0.75 0.07
12.7 21 1 (0.9%) 0.1 29.4 0.3 (1.2%) 0.27 0.01
3.8-12.7 113 116 {1 00%) 1.0 26.1 24.6 (100%) 0.21 0.22
IV 3.8 12 1 (33.3~b) 0.1 20.5 0.1 (25.0%) 0.65 0.01
5.1 12 2 (66.7%) 0.2 26.6 0.4 {75%) u.19 0.02
3.8-12.7 60 3 (1 00%) 0.1 24.6 0.4 ~IUO/~J 0.15 0.01
v 3.8 28 20 (66.7%) 0.7 21.3 1.9 (45.2%) 0.09 0.07
5.1 28 8 (26.7%) 0.3 25.8 1. 5 ( 35./%) 0.18 0.05
7.6 30 2 (6.7%) 0.1 33.0 0.9 (21.4%) 0.43 0.03
3.8-12.7 146 30 (100%) 0.2 23.3 4. 2 (100%) 0.14 0.03
I-V 3.8-12.7 689 169 0.3 26.4 32.8 0.19 0.05
a. A net night is one 47 metre gi11net fished for a 24 hour period.
b. Catch data by mesh size not available.
Mean
age
(yl')
5.9
13.0
8.0
9.0
10.0
3.2
4.4 1-'
.j:::>
7.7 U"l
10.0
7.0
4.6
4.0
6.5
5.7
2.5
3.5
7.5
3.1
5.8
147
Appendix IX
Age and length-frequency distributions of fishes from
the Lower Churchill River.
(i) Northern Pike
(ii) Lake Whitefish
(iii) Longnose Suckers
(iv) White Suckers
(v) Brook Trout
(vi) Burbot
(vii) Lake Trout
(viii) Ouananiche
(ix) Round Whitefish
149
Appendix IX (i). Age-frequency distribution by gillnet mesh size of northern
pike from the Lower Churchill River above Muskrat Falls, June-August, 1975-76.
Age Mesh size (em)
(yr) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
1
2 6 6
3 9 6· 1 16
4 3 5 1 9
5 2 6 10 4 22
6 3 5 10 13 1 32
7 1 12 13 1 27
8 3 7 6 2 18
9 1 4 8 8 1 22
10 6 1 5 6 1 19
11 4 3 1 4 1 13
12 2 1 1 3 1 8
13 3 1 1 5
14 2 3 1 6
15 2. 2 4
16 1 l
Totals 42 35 57 63 11 208
Appendix IX (i). Length-frequency distribution by gi11net mesh size of northern
pike from the Lower Churchill River above ~1uskrat Falls, June-August, 1975-76· ..
Length class Mesh size ~em~
(em) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
20.0-29.9 17 3 3 23
30.0-39.9 1 7 1 1 10
40.0-49.9 1 8 13 22
50.0-59.9 4 2 18 15 1 40
60.0-69.9 11 7 21 32 2· 73
70.0-79.9 4 3 2 7 2 18
BO. 0-89.9 4 2 2 7 3 18
90.0-99.9 2 3 1 6
1 00. 0-1 09 • 9 2 1 3
Totals 42 36 60 64 11 213
150
Appendix IX (i). Age-frequency distribution by gillnet mesh size of northern
pike from the Lower Churchill River, Section II, August, 1975 .
. -·----··--·--< --· ·-· ---------
Age Mesh ':>ize (em) (yr) 3.8 5.1 7.6 10.2 12. 7 3.8-12.7
1
2 6 6
3 9 6 1 16
4 3 5 8
5 2 4 8 15
6 l 2 6 1 10
7 1 3 2 6
8 2 6 5 1 14
9 1 3 4 5 1 14
10 5 1 4 4 14
11 3 3 1 4 11
12 2 1 1 3 7
13 2 1 3
14 l 1 3
15 2 1 3
16 1 1
Totals 36 28 34 28 5 131
Appendix IX (i)~ Length-frequency distribution by gillnet mesh size of
northern pike fran the Lower Churchill River, Section II, August, 1975.
'-~ ~ ~---~---"-
Length class Mesh size ~em)
(em) 3.8 5.1 7.6 10.2 12. 7 3.8-12.7
10.0-19.9 20 20.0-29.9 17 3
30.0-39.9 1 6 1 1 9
40.0-49.9 1 7 11 19
50.0-59.9 3 2 12 6 23
-60.0-69.9 9 4 8 12 1 34
70.0-79.9 3 2 2 3 1 11
80:0-89.9 2 1 7 1 11
90.0-99.9 2 1 1 4
1 f)f). n.,. 1 '·'~ • ~ @ " ..
lotals 36 29 34 29 5 133
151
Appendix IX (i). Age-frequency distribution by gillnet mesh size of northern
pike from the Lower Churchill River, Section III, June-July, 1976.
Age
(yr)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Totals
3.8 5.1
Mesh size (em)
7. 6 10.2 12.7 . 3.8-12.7
1 1
1 1
Appendix IX (i). Length-frequency distribution by gillnet mesh size of northern
pike from the Lower Churchill River, Section III, June-July, 1976.
Length c 1 ass 7"'"C;---~:-;----r;::-...:.M.:.::e~s h~s:.;;,i .::.;Ze~(.::,:cm::.:..)!..--:r::;-=;-----:=:-~;-;:;--
(cm) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
10.0-19.9
20.0-29.9
30.0-39.9
40.0-49.9
50.0-59.9.
·60.0-69.9
70.0-79.9
80.0-89.9
90.0-99.9
100.0-109 .. ~
Totals
1 1
152
Appendix I X ( i). Age-frequency dis tri buti on by g i 11 net mesh size of northern
pike from the Lower Churchill River, Section IV, July-August, 1976.
Age Mesh size (em)
(yr) 3.8 5.1 7.6 10.2 12. 7 3.8-12.7
1
2
3
4
5 1 1
6 1 1
7 2 2 4
8 1 1
9 1 4 5
10 2 3
11
12
13
14 1 1
15
16
Totals 3 2 6 5 16
Appendix IX (i). Length-frequency distribution by gillnet mesh size of northern
pike from the Lower Churchill River, Section IV, July-August, 1976.
Length class Mesh size (em)
(em) 3.8 5.1 7.6 10.2 12.7
1 a. o-19. 9
20.0-29.9
30.0-39.9 1 ' 1
40.0-49.9
50.0-59.9 1 1 2
60.0-69.9 5 3 8
70.0-79.9 1 1 2 4
-8o.0-89.9 1 1
90.0-99.9
JOQ Q-109.9
Totals 3 2 6 5 16
153
Appendix IX (i). Age-frequency distribution by gillnet mesh size of northern
pike from the Lower Churchill River, Section V, July-August, 1975.
Age Mesh size (em)
(yr) 3.8 5.1 7.6 10.2 12. 7 3.8-12.7
1
2
3
4 1 1
5 1 2 3 6
6 2 3 4 12 21
7 7 9 1 1'7
8 1 1 1 3
9 3 3
10 1 1 2
11 1 1
12 1 1
13 1 1 2
14 2 2
15 1--1
16
Totals 3 5 17 30 5 60
Appendix IX (i). Length-frequency distribution by gillnet mesh size of north~rn
pike from the Lower Churchill River, Section V, July-August, 1975.
Length class Mesh size (em)
(em) 3.8 5.1 7.6 10.2 12. 7 3.8-12.7
10.0-19.9
20.0-29.9
30.0-39.9
40.0-49.9 1 2 3
so.o-59.9 5 9 14
60-.0-69.9 2 3 8 17 1 31
70.0-79.9 2 1 3
80.0-89.9 1 1 2 2 6
90.0-99.9 2 2
HJC O-J09 9 1 1
Totals 3 5 17 30 5 60
154
Appendix IX(ii). Age-frequency distribution by gillnet mesh size of
lake whitefish from the Lower Churchill River above
Muskrat Falls, June-August, 1975-76.
Age
(yr) 3.8 5. 1
t~esh size (em)
7.6 10.2. 12.7 3.8-12.7
1 1 1 2
2 14 2 ' 16
3 8 12 1 1 22
4 2 11 13 1 27
5 10 14 5 29
6 4 10 35 17 1 67
7 1 7 38 20 1 67
8 2 2 33 25 62
9 3 2 38 21 1 65
10 1 ' 2 17 15 35
11 4 14 11 29
12 1 1 6 12 2 22
13 1 9 1 11
14 1 1
15 1 1
16 1 1
17 1 1
18
19
20 1 1
Totals 37 65 222 128 7 459
Appendix IX(ii). Length frequency distribution by gillnet mesh size of lake
whitefish from the lower Churchill River above Muskrat Falls, June-August,
1975-76.
Length class ·~· Mesh size (em)
(em) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
10.0-19.9 18 1 19
20.0-29.9 9 31 7 1 1 49
30.0-39.9 9 37 208 148 5 407
40.0-49.9 4 5 21 30 5 65
50.0-59.9 3 3
Totals 40 74 239 179 11 543
155
Appendix IX(ii). Age-freq e d" t ·b · · whitefish from the Lower C~u~~~ill,sR~1 ut5
10 "t?Y g1llnet mesh size of lake 1ve~ ec 1on II, August, 1975.
Age Mesh size (em)
(yr) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
1
2 13 1 14
3 8 8 1 17
4 5 5
5 4 1 5
6 2 3 9 1 15
7 1 14 3 18
8 7 1 8
9 3 1 11 2 1 18
10 1 4 4 9
11 2 6 5 13
12 3 8 1 12
13 1 5 1 7
14 1 1
15 1 1
16 1 1
17
18
19
20 1 1
Totals 26 27 63 24 5 145
Appendix IX( i i). Length-frequency distribution· by gill net mesh size
of lake whitefish from the Lower Churchill River, Section II, August,
1975.
Length class Mesh size (em)
(em) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
10.0-19.9 16 16
-20.0-29.9 6 17 4 1 1 29
30-0-39.9 4 9 48 16 1 78
40.0-49.9 1 1 8 8 3 21
50.0-59.9 1 1
, "'(otals 27 27 61 25 5 145
156
Appendix IX(ii). Age-frequency distribution by gillnet mesh size of lake
whitefic;h from the Lower Churchill River, Section III, June-July, 1976.
Age Mesh size (em)
(yr) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
1
2
3
4 2 2 5
5 1 6 1 8
6 2 12 6 20
7 3 9 6 18
8 1 4 11 16
9 1 7 12 20
10 5 2 7
11 2 3 5
12 2 2 4
13 1 1
14
15
16
17
18
19
20
Totals 1 10 so 43 104
Appendix IX(ii). Length-frequency distrjbution by gi1lnet mesh size of
lake whitefish from the Lower Churchill River, Section III, June-July,
1976.
Length class Mesh size ~em)
(em) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
10.0-19.9
20.0-29.9 1 3 4
30.0-39.9 5 47 55 107
. 40.0-49.9 2 6 8
50.0-59.9
Totals 1 8 49 61 119
157
Appendix IX(ii). Age-frequency distribution by gillnet mesh size of
lake whitefish from the Lower Churchill River, Section IV, July-August,
1976.
Age Mesh size (em)
(yr) 3.8 5.1 7.6 10.2 12.7 3.8 ... 12.7
1
2
3 3 3
4 1 4 1 6
5 1 1 2
6 2 2 2 7
7 1 3 4
8 1 4 5 10
9 7 7
10 3 3 7
11 2 2 3 7
12 1 1 2 4
13 1 1
14
15
16
17
18
19
20
Totals 4 9 25 20 58
Appendix IX(i;). Length-frequency distribution by gillnet mesh size of
lake whitefish from the Lower Churchill Rive~ Section IV, July-August,
1976.
Length class Mesh size (em)
(em) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
10.0-19.9 1 1
20.0-29.9 2 1 3
30.0-39.9 1 4 22 13 40
40.0-49.9 3 2 2 7 14
50.0-59.9
Totals 4 9 25 20 58
158
Appendix IX(ii). Age-frequency distribution by gillnet·mesh size
of lake whitefish from the Lower Churchill River, Section V, July-
August, 1975.
Age Mesh size (em)
(yr) 3.8 5.1 7.6 10.2 12.7
1 1 1
2 1 1
3 1 1
4 1 3 7
5 5 6 3
6 1 3 12 9
7 1 2 15 8 1
8 1 1 18 8
9 13 7
10 1 5 6
11 4
12 1
13 2
14
15
16
17 '1
18
19
20
Totals 6 19 84 41 2
3. 8-12.7
2
2
2
11
14
25
27
28
20
12
4
2
2
1
152
Appendix IX(ii). Length-frequency distribution by gillnet mesh size of lake
whitefish from the Lower Churchill River, Section V, July-August, 1975.
Length class Mesh size (em)
(em) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
1 0 .0-19. 9 2 2
20.0-29.9 2 9 2 13
30.0-39.9 4 19 91 64 4 182
. 40.0-49.9 2 9 9 2 22
50.0-59.9 2 2
Tota 1 s 8 30 104 73 6 221
I
I
159
Appendix IX(iii). Age-frequency distribution by gillnet mesh size of
1ongnose suckers from the Lower Churchill River above Muskrat Falls,
June-August, 1975-76.
Age Mesh size (em)
(yr) 3.8 5.1 7.6 10.2 12. 7 3.8-12.7
1
2
3 16 16
4 25 4 29
5 35 12 47
6 6 25 31
7 7 38 3 48
8 4 20 7 31
9 1 9 21 31
10 15 37 2 54
11 7 61 3 71
"12 2 45 3 1 51
13 4 25 16 45
14 13 4 1 18
15 1 4 1 6
16 1 5 1 -1 8
17
18
19 1 1
Totals 95 137 222 30 3 487
Appendix IX(iii). Length-frequency distribution by gillnet mesh size of
longnose suckers from the Lower Churchill River above Muskrat Falls,
June-August, 1975-76.
Length class Mesh size ~em)
(em) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
10.0-19.9 160 2 162
20.0-29.9 34 168 8 210
.30. 0-39.9 1 52 402 19 474
40.0-49.9 2 21 29 2 54
50.0-59.9 1 1 2
· Jota1 s 195 224 432 48 3 902
160
Appendix IX(iii). Age-frequency distribution by gillnet mesh size of
longnose suckers from the Lower Churchill River, Section II, August, 1975.
Age Mesh size (em)
(yr) 3.8 5.1 7.6 10.2 12.7 3. 8-12.7
1
2
3
4 5 1 6
5 8 8
6 4 4
7 1 7 8
8 1 4 1 6
9 1 3 4
10 1 1
11 1 5 6
12 1 1
13 2. 3 5
14 2 1 1 4
15
16
17
18
19
Totals 15 18 14 5 1 53
Appendix IX(iii). Length-frequency distribution by gillnet mesh size of
longnose suckers from the Lower Churchill River, Section II, August, 1975.
Length class Mesh size (em)
(em) 3.8 5.1 7.6 10.2 12.7 3.. 8-12.7
-10.0-19.9 13 13
20.0-29.9 2 17 19
30.0-39.9 2 12 1 15
40.0-49.9 2 5 1 8
50.0-59.9
Totals 15 19 14 6 1 55
161
Appendix IX(iii). Age-frequency distribution by gillnet mesh size of longnose
suckers from the Lower Churchill Rive~ Section III, June-July, 1976.
Age Mesh size (em)
(yr) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
1
2
3 1 1
4 6 6
5 16 4 20
6 4 9 13
7 3 11 2 16
8 2 5 4 11
9 3 13 16
10 8 22 2 32
11 2 20 3 25
12 24 2 1 27
13 1 6 9 16
14 2 2 4
15 1 1 2
16
17
18
19
Totals 32 43 94 19 1 189
Appendix IX(iii). Length-frequency distribution by gi1lnet mesh size of
1ongnose suckers from the Lower Churchill Rive~ Section III, June-July, 1976.
Length class Mesh size (em)
(em) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
10.0-19.9 43 1 44
20.0-29.9 18 45 2 65
30.0-39.9 16 116 12' 1 145
40.0-49.9 1 3 10 14
50.0-59.9
Totals 61 63 121 22 1 268
"/' l
162
Appendix IX(iii). Age-frequency distribution by gillnet mesh size of longnose
suckers from the Lower Churchill Rive~ Section IV, July-August, 1976.
Age Mesh size (em)
(yr) 3.8 5.1 7.6 10.2 12. 7 3.8-12.7
1
2
3
4
5
6
7 1 1
8 3 3
9 2 1 3
10 1 10 11
11 1 17 18
]'2 20 20
13 1 16 4 21
14 7 1 8
15 1 3 4
16 5 1 1 7
17
18
19 1 1
Totals 1 9 80 6 1 97
Appendix IX(iii). Length-frequency distribution by gillnet mesh size of
longnose suckers from the Lower Churchill River,Section IV, July-August,
1976.
Length class Mesh size (em)
(em) 3.8 5.1 7.6 10.2 12.7 3. 8-12.7
10.0-19.9 1 1
20.0-29.9 9 3 12
30.0-39.9 4 128 4 136
40.0-49.9 10 9 1 20
50.0-59.9 1 l 2
Totals 1 13 142 13 2 171
163
Appendix IX(iii). Age-frequency distribution by gillnet mesh size of longnose
suckers from the Lower Churchill River,Section V, July-August, 1975.
Age Mesh size (em)
(yr) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
1
2
3 15 15
4 14 3 17
5 11 8 19
6 2 12 14
7 '3 19 1 23
8 1 8 2 11
9 1 3 4 8
10 6 4 10
11 3 19 22
12 2 1 3
13 2 1 3
14 2 2
15
16 1 1
17
1'8
19
Totals 47 67 34 148
Appendix IX(iii). Length-frequency distribution by gillnet mesh size of long-
nose suckers from the Lower Churchill River, Section V, July-August, 1975.
Length class Mesh size (em)
(em) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
10.0-19.9 103 1 104
-20. 0•29. 9 14 97 3 114
30.0-39.9 1 30 146 2 179
40.0-49.9 1 6 4 11
50.0-59.9
'Totals 118 129 155 6 408
164
Appendix IX(iv). Age-frequency distribution by gillnet mesh size of white
suckers from the Lower Churchill River above Muskrat Falls, June-August,
1975-76.
Age Mesh size (em)
(yr) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
1
2
3 20 20
4 11 18 2 31
5 11 23 2 36
6 4 36 11 51
7 1 11 52 3 67
8 3 17 9 29
9 5 17 7 29
10 6 14 20
11 1 1 14 28 44
12 l 6 27 34
13 1 9 18 1 29
14 1 6 12 1 20
15 1 4 '1 6
16 1 1
17 1 1
18 1 1
]9
Totals 48 100 143 124 4 419
Appendix IX(iv). Length-frequency distribution by gi11net mesh sjze of white
suckers from the Lower Churchill River above f·luskrat Falls, June-August,
1975-76.
Length class Mesh size (em) ~~--~~----~~~~~~~~~~=-------~~~ (em) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
10.0-19.9 43 1 44
-20.0-29.9 6 84 6 96
30.0-39.9 13 118 34 165
40.0-49.9 2 4 38 97 4 145
50.0-59.9 1 1 1 3
, Totals 51 102 163 132 5 453
165
Appendix IX(iv). Age-frequency distribution by gillnet mesh size of white
suckers from the Lower Churchill Rive~Section II, August, 1975.
Age Mesh size (em)
(yr) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
1
2
3 16 16
4 6 11 2 19
5 6 17 2 25
6 1 3 9 13
7 6 30 1 37
8 9 6 15
9 2 3 6 11
10 3 3
11 1 5 6
12 2 2
13 1 1 2
14
15
16
17
18
19
Totals 29 39 57 24 149
Appendix IX(iv). Length-frequency distribution by gi1lnet mesh size of white
suckers from the Lower Churchill Rive~ Section II, August, 1975.
Length class Mesh size (em)
(em) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
10.0-19.9 28 28
-20.0-29.9 1 33 5 39:
30.0-39.9 6 55 12 73
40.0-49.9 1 11 18 30
50.0-59.9 1 1
Totals 29 40 72 30 171
166
Appendix IX(iv). Age-frequency distribution by gillnet mesh size of white
suckers from the Lower Churchill Rive~ Section III, June-July, 1976.
Age Mesh size (em)
(yr) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
l
2
3 1 l
4 2 l 3
5
6 l 1
7 8 2 10
8 2 2 4
9
10
11 l l
12
13
14
15
16
17
18
19
Totals 3 1 11 5 20
Appendix IX(iv). Length-frequency distribution by gillnet mesh size of whi.te
suckers from the Lower Churchill River, Section III, June-July, 1976.
Length class Mesh size (em)
(em) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
10.0-19.9 1 1
-20.0-29.9 2 1 3
30.0-39.9 11 4 15
40.0-49.9 1 1
50.0-59.9
Total 3 1 11 5 20
-
167
Appendix IX(iv). Age-frequency distribution by gillnet mesh size of white
suckers from the Lower Churchill River, Section IV, July-August, 1976.
Age Mesh size (em)
(yr) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
1
2
3
4
5 5 3 8
6 2 29 31
7 2 2
8 3 2 5
9 1 12 1 14
10 2 3 5
11 1 3 5 9
12 1 4 6 11
13 1 3 4 8
14 1 4 2 7
15 1 1
16
17 1 1
18
19
Totals 8 39 33 22 102
Appendix IX(iv). Length-frequency distribution by gillnet mesh size of
white suckers from the Lower Churchill River,Section IV, July-August, 1976.
Length class Mesh size (em)
(em) 3.8 5.1 7.6 10.2 12.7 3.8-12:7
10.0-19.9 6 1 7
20.0-29.9 1 34 35
30.0-39.9 2 22 7 31
40.0-49.9 2 2 15 20 1 40
50.0-59.9
Totals 9 39 37 27 1 113
168
Appendix IX(iv). Age-frequency distribution by gillnet mesh size of white
suckers from the Lower Churchill Rive~ Section V, July-August, 1975.
Age Mesh size (em)
(yr) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
1
2
3 3 3
4 3 6 9
5 3 3
6 1 4 1 6
7 1 5 12 18
8 4 1 5
9 2 2 4
10 4 8 12
11 1 10 17 28
12 2 19 21
13 5 13 1 19
14 2 10 1 13
15 4 1 5
16 1 -1
17
18 1 1
19
Totals 8 21 42 73 4 148
Appendix IX(iv). Length-frequency distribution by gil1net mesh size of
white suckers from the Lower Churchill River,Section V, July-August, 1975.
Length class Mesh size (em)
(till) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
10.0-19.9 8 8
20.0-29.9 2 16 1 19
30.0-39.9 5 30 11 46
40.0-49.9 1 12 58 3 74
50.0-59.9 1 1 2
' Totals 10 22 43 70 4 149
169
Appendix IX (v). Age-frequency distribution by gillnet mesh size of brook
trout from the Lower Churchill River above Muskrat Falls, June-August,
1975-76.
Age Mesh size (em)
(yr) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
1 2 2
2 28 -,. 1 1 37 I
3 23 38 20 18 2 101
4 2 5 51 17 75
5 1 12 4 4 21
6 1 2 3
TOTALS 55 51 85 42 6 239
Appendix IX (v). Length-Frequency distribution by gillnet mesh size of
brook trout from the Lower Churchill River above Muskrat Falls, June-August,
1975-76.
Length class Mesh size (em)
(em) 3.·8 5.1 7.6 10.2 12.7 3.8-12.7
10. Q.,-19 ~·9 57 1 7 65
20.0-29.9 20 66 12 3 101
30.0..,.39.9 6 19 220 41 286
40.0-49.9 1 1 31 51 4 88
50.0-59.9 1 1
TOTALS 84 87 270 93 7 541
170
Appendix IX(v). Age-frequency distribution by gillnet mesh size of brook
trout from the Lower Churchill River, Section III, June-July, 1976.
Age Mesh size (em)
(yr) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
1 1 1
2 23 j 24
3 21 21 14 1 57
4 3 29 10 42
5 6 11 17
6 1 2 3
Totals 45 25 50 23 1 144
Appendix IX ( v). Length-frequency di stri bL•ti on by gi 11 net mesh size of brook
trout from the Lower Churchill Rive~ Section III, June-July, 1976.
Length class Mesh size (em)
(em} 3 .. 8 5.1 7.6 10.2 12.7 3.8-12.7
10.0-19.9 51 6 57
20.0-29.9 17 45 12 2 76
30.0-39.9 5 16 186 30 237
40.0-49.9 1 29 46 76
50.0-59.9
Totals 74 61 233 76 2 446
171
Appendix IX(v). Age-frequency distribution by gillnet mesh size of brook
trout from the Lower Chuchill River, Section IV, July-August, 1976.
Age Mesh size (em)
(yr) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
1
2
3
4 1 1 1 3
5 1 1 2
6
Totals 1 2 2 5
Appendix IX(v). Length-frequency distribution by gill net mesh size of brook
trout from the Lower Churchill Rive~ Section IV, July-August, 1976.
Length class Mesh size (em)
(em) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
10.0-19.9
20.0-29.9
30.0-39.9 1 1 2 4
40.0-49.9 1 1
50.0-59.9
Totals 1 2 2 5
172
Appendix IX(v). Age-frequency distribution by gillnet mesh size of brook
trout from the Lower Churchill Rive~ Section V, July-August, 1975.
Age Mesh size (em)
(yr) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
1 1 1
2 4 ' 6 1 11
3 2 16 6 1 1 26
4 1 1 21 8 31
5 7 5 4 16
6 2 2
Totals 8 23 35 16 5 87
Appendix IX(v). Length-frequency distribution by gillnet mesh size of brook
trout from the Lower Churchill River, S2ction V, July-August, 1975.
Length class Mesh size (em)
(em) 3.8 5.1 7.6 10.2 .12.-7 3.8-12.7
10.0-19.9 5 1 1 7
20.0-29.9 3 20 1 24
30.0-39.9 2 32 10 44
40.0-49.9 2 5 4 11
50.0-59.9 1 J.
Totals 8 23 35 16 5 87
\f'' j_ ;,p', I
173
Appendix IX(vi). Age-freauency distribution by gillnet mesh size of burbot
from the Lower Churchill River above Muskrat Falls, June-August, 1975-76.
Age Mesh size (em)
(yr) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
3 2 1 1 4
4 2 3 5
5 9 1 10
6 1 5 1 7
7 1 10 11
8 3 3
9 4 2 6
10 3 2 2 7
11 2 8 1 11
12 1 1 2
13 2 2
14 1 1
Totals 2 13 32 15 _7 69
Appendix IX (vi). Length-frequency distribution by gillnet mesh size of burbot
from the Lower Churchill River above Muskrat Falls, June-August, 1975-76.
Length class Mesh size (em)
(em) 3.8 5.1 7.6 10.2 12. 7 3.8-12.7
20.0-29.9 2 6 1 1 2 12
30.0-39.9 7 3 10
40.0-49.9 27 3 30
50.0-59.9 2 16 18
60.0-69,9 2 6 8
Totals 2 13 33 22 8 78
174
Appendix IX(vi). 1\ge-frequency distribution by gillnet mesh size of burbot
from the Lower Churchill River, Section II, .1\ugust, 1975.
Age Mesh size (em)
(yr) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
1
2
3
4
5 1
6 2 2
7 1 2 3
8 1 1
9 4 4
10 1 1 2
11
12
13
14
Totals 5 7 13
Aopendix IX(vi). Length-frequency distribution by gillnet mesh size of burbot
from the Lower Churchill River, Section II, August, 1975.
Length class Mesh size (em)
(em) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
lQ.'J-19.9
20.0-29.9
3').0-39.9 1 •; 1
40.'J-49.9 5 2 7
50.0-59.9 4 4
~IJ.'l_(-;!J.'l 1 1
Tota 1 s 5 7 13
(\
~,
-
175
~onendix IX(vi). Age-frequency rlistribution by gillnet mesh size of burbot
from the Lower Churchill River, Section III, June-July 1976.
Age Mesh size (em)
(yr) 3.8 5.1 7.6 10.2 12. 7 3.8-12.7
1
2 1 1 2
3
~ 1 1 2
1 1
6 3 3
7 4 4
8 1 1
9 1 1
1')
11
12
1,j
14 1 -
Totals 2 11 2 1 16
Appendix IX(vi). Length-frenuency distribution by gillnet mesh size of burbot
from the Lower Churchill River, Section III, June-July, 1976.
Length class Mesh size (em)
(em) 3.8 5.1 7.6 10.2 12.7 3.8-'12.7
10.0-19.9
20.0-29.9 1 1 2 4
30.1)-39.9 1 1 2
40.1)-49.9 8 8
5'l.'J-59.9 2 2 4
fifl.'l-f;Q,O
Iota Is ~'~ 12 ·5 ,.., 18 '-'-
176
Appendix IX( vi). Age-frequency rlistri:ution by gill net me'sh si·ze of burbot
from the Lower Churchill River, Section IV, July-August, 1976.
Age Mesh size (em)
(yr) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
1
2
3
4 2 2
5 3 1 4
6
7 5 5
8
9 2 1 3
11) 2 1 2 5
11 1 2 3
12
13 1
14
Tota 1 s 3 13 4 3 23
Appendix IX(vi). Length-frequencv distribution by gillnet mesh size of burbot
from the Lower Churchill Ri~er, Section IV, July-August, 1976.
Length class Mesh size (em)
(em) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
10.0-19.9
2'l.IJ-29.9
3') .IJ-39 . 9 3 2 5
40.0-49.9 11 1 12
5().f"J-5Q,Q 2 2
60.0-69.9 1 ~ 4
Tota 1 s 3 13 4 3 23
177
Appendix IX(vi). Age-frequency distribution by gillnet mesh size of burbot
from the Lower Churchill River, Sectton V, July-.A.ugust, 1975.
Age Mesh size (em)
(yr) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
1
2
3 2 2
4 1 1
5 4 4
6 1 2
7 1 1
8 1 1
9 2 2
1~ 1 1
11 6 1 7
12 1 1 2
13 1 1
14
Totals ? 7 3 9 3 24 ...
Appendix IX( vi). Length-frequencv distribution by gill net mesh size of burbot
from the Lower Churchill River, Section V, July-A.ugust, 1975.
Length class Mesh size (em)
(em) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
lf). ~-19. 9
20.0-29.9 2 5 1 8
30.0-39.9 2 2
40.0-49.9 3 3
5£1.0-59.9 8 8
60.0-69.9 3 1
Totals 2 7 3 9 3 24
178
Appendix IX(vii). Age-frequency distribution by gillnet mesh size of lake
trout f~om the Lower Churchill River above the site of the Gull Island dam,
June-August, 1975-76.
Age Mesh size (em)
(yr) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
6 2 2
7 1 1
8
9 1 1
10 2 1 3
11 1 1
12 1 1
13 1 1
14 1 2 3
15 1 1 2
Totals 1 1 1 9 3 15
Length class Mesh size (em)
(em) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
30.0-39. §l 1 1 40.0-49. 9 2
50.0-59.9 2 1 3
60.0-69. 9 1 3 4
70.0-79. 9 3 3
80.0-89. s 1 1
90.0-99.9 1 1 1
1
Tota 1 s 1 1 1 9 3 15
179
Appendix IX(vii). Age-frequency distribution by gillnet mesh size of lake
trout from the Lower Churchill River, Section III, June-July, 1976 .
Age Mesh size .(em)
(yr) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
1
2
3
4
5
6 2 2
7
8
9 1 1
10
11
12
13
14
15
Totals 3 3
Appendix IX(vii). Length-frequency distribution by gillnet mesh size of lake
trout from the Lower Churchill River, Section III, June-July, 1976
Length class Mesh size ~em)
(em) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
30.0-39.9 1 1
40.0-49.~ 2 2
50.0-59.9
60.0-69.9
70.0-79.~
80.0-89.9
90.0.99.9
Totals 3 3
180
Appendix IX(vii). Age-frequency distribution by gillnet mesh size of lake
trout from the Lower Churchill River, Section IV, July-August, 1976
Age Mesh size (em)
(yr) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
1
2
3
4
5
6
7
8
9
10 2 1 3
11
12 1 1
13 1 1
14 1 1 2
15 1 1
Totals 6 2 8
Appendix IX(vii). Length-frequency distribution by gillnet mesh size of lake
trout from the Lower Churchi 11 River, Section IV, July-August, 1976.
Length class Mesh size (em)
(em) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
30.0-39.9
40.0-49.9 1 1
50.0-59.9 3 3
60.0-69.9 3 3
70.0-79.9 1 1
80.0-89.9
90.0-99.9
Totals 6 2 8
('";
181
Appendix IX(vii). Age-frequency distribution by gillnet mesh size of lake
trout from the Lower Churchill River, Section V, July-August, 1975.
Age Mesh size (em)
(yr) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
1
2
3
4
5
6
7 1 1
8
9
10
11 1 1
12
13
14 -1 1
15 1 1
Totals 1 1 1 1 4
Appendix IX(vii). Length-frequency distribution by gillnet mesh size of lake
trout from the Lower Churchill River, S2ction V, July-August, 1975.
Length class Mesh size (em)
(em) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
30.0-39,9 1 1
40.0-49.9
50.0-59.9 1 1
60.0-69.9
70.0-79.9
-80.0-89.9 1 1
90.0-99.9 1 1
Totals 1 1 1 1 4
'
182
Appendix IX(viii). Age-frequency distribution by gillnet mesh size of
ouananiche from the Lower Churchill River above the site of the Gull Island
dam, June-August, 1975-76.
Age Mesh size (em)
(yr) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
3 1 1
4 l 1
5 2 1 1 4
6 3 3 2 1 9
7 1 1 2 5 1 10
8 2 1 1 4
9 1 1
Totals 9 7 4 8 2 30
Appendix IX(viii). Length-frequency distribution by gillnet mesh size of
ouananiche from the Lower Churchill River above the site of the Gull Island
dam, June-August, 1975-76.
Length class Mesh size (em)
(em) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
10.0-19.9 1 1
20.0-29.9 2 2
30.0-39.9 1 1 2
40.0-49.9 4 2 4 5 1 16
50.0-59.9 2 3 2 1 8
60.0-69.9 1 1
Totals 9 7 4 8 2 30
183
Appendix IX(viii). Age-frequency distribution by gillnet mesh size of
ouananiche from the Lower Churchill River, Section III, June-July, 1976.
Age Mesh size (em)
(yr) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
1
2
3
4
5 1 1
6
7 1 1
8
9
Totals 1 1 2
Appendix IX(viii). length-frequency distribution by gillnet mesh size of
ouananiche from the Lower Churchill River, Section III, June-July, 1976.
Length class Mesh size (em)
(em) 3.8 5.1 7.6 10.2 12.7 3;8-12.7
10.0-19.9
20.0-29.9 1 1
30.0-39.9
40.0-49.9 1
50.0-59.9
60.0-69.9
Totals 1 1 2
184
Appendix IX(viii). Age-frequency distribution by gi1lnet mesh size of
ouana~iche from the Lower Churchill River, Section IV, July-August, 1976.
Age Mesh size (em)
(yr) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
1
2
3 1 1
4
5 2 2
6 3 1 1 5
7 1 1 1 1 4
8 2 1 1 4
9 1 1
Totals 8 3 3 2 17
Appendix IX(viii). Length-frequency distribution by gillnet mesh size of
ouananiche from the Lower Churchill River, Section IV, July-August, 1976.
Length class Mesh size (em)
(em) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
10.0-19.9 1 1
20.0-29.9
30.0-39.9 1 1
40.0-49.9 3 1 1 1 6
50.0-59.9 2 3 2 1 8
60.0-69.9 1 1
Totals 8 3 1 3 2 17
185
Appendix IX(viii). Age-frequency distribution by gillnet mesh size of
'Ouananiche from the Lower Churchill River, Section V, July-August, 1975.
Age Mesh size (em)
(yr) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
1
2
3
4 1 1
5 1 1
6 2 2 4
7 1 1 3 5
8
9
Totals 1 3 3 4 11
Appendix IX(viii). Length-frequency distribution by gillnet mesh size of
ouananiche from the Lower Churchill River, Section V, July-August, 1975.
Length class Mesh size (em)
(em) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
10.0-1 9. 9
20.0-29.9 1 1
30.0-39.9 1 1
40.0-49.9 1 2 3 3 9
50.0-59.9
60.0-69.9
Totals 1 3 3 4 11
186
Anpendix IX(ix). Age-frequen'cy distribution by gillnet mesh size of round
whitefish from the Lower Churchill River above Muskrat Falls, June-August, 1975-76.
Age Mesh size (em)
(yr) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
1
2 15 1 16
3 39 12 51
4 6 19 25
5 1 10 11
6 1 4 3 8
7 2 7 10
8 1 2 7 1 11
9 3 1 4
10 2 2
11
12 1 2'
13 1
Totals G3 51 23 3 1 141
Appendix IX(ix). Length-frequency distribution by gillnet mesh size of round
whitefish from the Lower Churchill River above Muskrat Falls, June-Auqust, 1975-?n.
Length class Mesh size (em)
(em) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
lf).IJ-19.9 29 29
2'>.0-29.9 37 51 1 89
30.1)-39.9 2 5 22 3 32
4'>.'1-49.9 1 1 2
Tota 1 s 68 57 23 3 152
187
Appendix IX(ix). Age-frequency distribution by gillnet mesh size of round
whitefish from the Lower Churchill River, Section III, June-July, 197ti.
Age Mesh size (em)
(yr) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
1
2 1 1 2
3 36 6 42
4 3 19 22
5 8 8
6 1 3 3 .7
7 1 6 8
8 1 2 5 9
9 3 3
1'1 2 2
11
12 1 2
13
Tota 1 s 42 40 21 .., 1 105 -
~opendix IX(ix). Length-frequency distribution by gillnet mesh size of round
whitefish from the Lower Churchill River, Section III, June-July; 1976.
Length class Mesh size (em)
(em} 3.8 5.1 7.6 10.2 12.7 3.8-12.7
10.1)-19.9 19 19
20.1)-29.9 27 41 69
30.'1-39.9 1 5 19 2 27
40.0-49.9 1 1
Totals 47 46 2') 2 116
188
Appendix IX(ix). Age-frequencj dtstributinn by gillnet mesh size of round
whitefish from the Lower Churchill River, Section IV, July-August, 1976.
Age
(yr)
1
2
3
4
5
6
7
8
9
10
11
12
13
Totals
3.8 5.1
2
Mesh size (em)
7.6 10.2 12.7 3.8-12.7
1
1
3
Appendix IX(ix). Length-frequency distribution by gillnet mesh size of round
whitefish from the Lower Churchill River, Section IV, July-August, 1976.
Length class Mesh size (em) ~~--~~----~~~~~~~~~--~~------~~~~ (em) 3.8 5.1 7.6 10.2 12.7 J.B-12.7
10.0-19.9
20.0-29.9
30.0-39.9
40.0-49.9
Totals
2 3
2
189
Appendix IX(ix). Age-frequency distribution by gillnet mesh size of round
whitefish from the Lower Churchill River, Section V, July-August, 1975.
Age Mesh size (em)
(yr) 3.8 5.1 7.6 10.2 12.7 3. 8-12.7
1
2 14 14
3 3 6 9
4 2 2
5 1 2 3
6
7 1
8 1
9
10
11
12
13
Trotal s 20 8 2 3f)
Appendix IX(ix). Length-frequency distribution by gillnet mesh size of round
whitefish from the Lower Churchill River, Section V, July-August, 1975.
Length class Mesh size (em)
(em) 3.8 5.1 7.6 10.2 12.7 3.8-12.7
10.1)-19.9 1') 10
20.0-29.9 9 8 17
30.0-39.9 1 2 3
41).0-49.9
Totals 2() 8 2 31)
~'':.<%' 4 !' k-' / i ~ '