HomeMy WebLinkAboutAPA2628Effects on Arctic Grayling (Thymallus
arcticus} of Prolonged Exposure
to Yukon Placer Mining Sediment:
A Laboratory Study
D. J. Mcleay, G. L. Ennis, I. K. Birtwell,
and G. F. Hartman
Department of Fisheries and Oceans
Habitat Management Division
Field Services Branch
1090 West Pender Street
Vancouver, British Columbia V6E 2P1
January _1984
Canadian Technical Report of
Fisheries and Aquatic s ·ciences
No. 1241 ·
Fis heries P~ches
8fl d Oceans et Oceans Canada
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Canadian Technical Report or Fisheries
and Aquatic Sciences No. 1241
Yukon River Basin Study
Fisheries Project Report No. 9
January 1984
EFFECTS ON ARCTIC GRAYLING
(Thymallus arcticus)
OF PROLONGED EXPOSURE TO
YUKON PLACER MINING SEDIMENT:
A LABORATORY STUDY
by
D. J. McLeay1, G •. L. Ennis2a,
I. K. Birtwe112b and G. F. Hartman2c
1D. McLeay & Associates Ltd., Suite 300, 1497 Marine Drive,
West Vancouver, B.C. V7T 1B8
2Fisheries and Ocean Canada
a) Habitat Management Division, Field Services Branch,
1090 West Pender Street, Vancouver, B.C. V6E 2P1
b) Salmon Habitat Section, Fisheries Research Branch,
West Vancouver Laboratory, 4160 Marine Drive,
West Vancouver, B.C. V7V 1N6
c) Salmon Habitat Section, Fisheries Research Branch,
Pacific Biological Station, Nanaimo, B.C. V9R 2P1
-J.J. -
(c)MJ.mster of Supply and SerVJ.ces Canada 19ti4
Cat. No. Fs 97-6/1241 ISSN U7U6-6457
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TABLE OF CONTENTS
PREFACE iii
TABLE OF CONTENTS iv
LIST OF TABLES • • vi
LIST OF FIGURES .• viii
ABSTRACT . . . . ~ . . . . . .
RESUME •
INTRODUCTION
MATERIALS AND METHODS
TEST FISH
Fish collection
Fish rearing • • •
TEST SEDIMENT • • • • •
Sediment collection . . . . . . . . . . . . .. . .
Sediment preparation and analyses
EXPERIMENTAL • • • • • • • • •
Test apparatus • •
Treatment of fish
Test strengths of sediment • • • • •
Water quality monitoring . • •••
Fish growth • • • • • • • • • .
Fish behaviour • • • • • • • • • • • • • • •
Fish condition . . . . . . • . . . . . . ~ .
Fish performance • • • • • • • • • • • '~ • • • •
Statistical analyses • • • • •
RESULTS • • • • • • • • • • •
SEDIMENT CHARACTERISTICS AND DISPERSAL
WATER QUALITY • • • • •
FISH SURVIVAL AND GROWTH
FISH BEHAVIOUR • • • • •
Distribution in streams
Feeding response trials
CONDITION OF FISH • • • • • • • • 0 • • • • • •
General
Fish length and condition factor
Biological characteristics • • •
PERFORMANCE OF FISH • • • • • • • • •
Tolerance to reference
Respiration • • • • •
Temperature tolerance
toxicant
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PREFACE
This study, along with other work on short-term exposures of Arctic
grayling, including studies of fish food habits and distribution, was
carried out to provide some initial information on the effects of placer
mining·sediments on this species of fish. While this work indicates the
nature of certain physiological and behavioural responses of Arctic
grayling to suspended sediment, it is recognized that a longer term
programme of more comprehensive studies on the effects of sediments on
various stages in the life cycle of grayling and their habitat are
desirable.
Although we would urge caution in the interpretation and
application of this first stage of research, it is hoped that the
present findings together with those from our previous investigations
with Arctic grayling, will provide information necessary for the
sensitive and well-informed management of aquatic resources.
The Yukon River Basin Study (a joint study by Canada, Yukon, and
British Columbia of the waters and related resources of the Yukon Basin)
and the Department of Fisheries and Oceans Canada (Field Services Branch
and Fisheries Research Branch) funded this project. Statements made are
those of the authors and not necessarily those of the Yukon River Basin
Committee nor Parties to the Basin Agreement. The work was a co-
operative undertaking by D. McLeay & Associates Ltd. and staff of the
Department of Fisheries and Oceans.
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DISCUSSION • • • • • • • • • ·• . • • • • • • • • • • • •
SEDIMENT DISPERSAL/CONCENTRATION IN TEST STREAMS •••
FISH SURVIVAL AND GROWTH • • • • •. • • • • • • • • • •
FISH DISTRIBUTION • • • • • • • • • •
FEEDING BEHAVIOUR OF FISH • • • • • • • • • • •
FISH CONDITION • • • • • • • • • • • • • • •
FISH PERFORMANCE • • • • • •
GENERAL • • • • • • • • • • • •
ACKNOWLEDGEMENTS
REFERENCES • . . . . . . . . . . . .. . . . .
TABLES •
FIGURES.
APPENDIX
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Table ---
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LIST OF TABLES
Particle size distribution for test sediment collected
from a placer mine settling pond.
Oxygen uptake rate, volatile ci.nd fixed residue for test
sediment collected from a placer mine settling pond.
Metal content for test sediment collected from a placer
mine settling pond.
4 Effect of stream position on suspended sediment strength.
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Summary of water quality characteristics in test streams
during the 6-week period of exposure of underyearling
Arctic grayling to differing strengths of suspended
placer mining sediment.
Weekly mortalities of underyearling Arctic grayling in
test streams during prolonged exposure to differing
strengths of placer mining sediment.
Weekly weights for groups of underyearling Arctic gray-
ling exposed for 6 weeks to differing strengths of sus-
pended placer mining sediment.
Percentage distribution of underyearling Arctic grayling
in four equal portions of each test stream following ex-
posure of fish to suspended placer mining sediment for 4
or 5 weeks.
Effect of differing strengths of suspended placer mining
sediment on the feeding response to surface drift
(Drosophila melanogaster) for underyearling Arctic gray-
ling held in test streams for 5 weeks.
Effect of differing strengths of suspended placer mining
sediment on the feeding response to surface drift
(Drosophila melanogaster) for underyearling Arctic gray-
ling held in test streams for 1 hour prior to testing.
11 Effect of differing strengths of suspended placer mining
sediment on the feeding .response to sub~surface drift
(Artemia salina) for underyearling Arctic grayling held
in test streams for 6 weeks.
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Table
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LIST OF TABLES (cont'~ )
Effect of differing strengths of suspended placer mJ.nJ.ng
sediment on the feeding response to a benthic
invertebrate ( tubificid worms) for underyearling Arctic
grayling held in test streams for 5 weeks vs. 1 hour
prior to testing.
Length, weight, and condition factor of underyearling
Arctic grayling following exposure to differing strengths
of suspended placer mining sediment for 3 or 6 weeks.
Biological characteristics determined for underyearling
Arctic grayling following exposure to differing strengths
of suspended placer mining sediment for 6 weeks.
Acute lethal tolerance of underyearling Arctic grayling
to the reference toxicant pentachlorophenol following
exposure . to differing strengths of suspended placer
mining sedimen't for 3 weeks.
Acute lethal tolerance of underyearling grayling to the
reference toxicant pentachlorophenol following exposure
to differing strengths of suspended placer mining
sediment for 6 weeks.
Response of underyearling Arctic grayling to hypoxia fol-
lowing exposure to differing strengths of suspended
placer mining sediment for 6 weeks.
Upper lethal temperature tolerance of underyearling
Arctic grayling following exposure to differing strengths
of suspended placer mining sediment for 6 weeks.
Figure
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-viii -
LIST OF FIGURES
Illustration of test streams showing reservoir barrels,
barrel stirrers, peristaltic pumps for dispensing
sediment suspensions, recycle pumps and air supply.
Relationship of nonfiltrable residue (NFR) concentration
of placer mining sediment added to barrel vs. suspended
sediment strength within test streams.
Illustration of daily fluctuations in concentration of
nonfiltrable residue within each test stream throughout
the 6-week exposure period.
Illustration of daily fluctuations in turbidity within
each test stream throughout the 6-week exposure period.
Effect of suspended placer mining sediment on the growth
(weekly wet weight gain) of underyearling Arctic gray-
ling.
Illustration of effect of differing strengths of
suspended placer mining sediment on feeding response for
underyearling Arctic grayling held in test streams for
(a) 5 weeks or (b) 1 hour prior to testing.
Illustration of effect of differing strengths of
suspended placer m1n1ng sediment on time to consume
groups of 10 benthic worms (tubificids) for underyearling
Arctic grayling held in test streams for ,(1;1.) 5 weeks or
(b) 1 hour prior to testing.
Illustration of effect of d-iffering strengths of
suspended placer m1n1ng sediment on time to consume
groups of 10 sub-surface drift organisms (Artemia salina)
for underyearling Arctic grayling held in test streams
for 6 weeks prior to testing.
Effect of 3-week exposure of underyearling Arctic gray-
ling to suspended placer mining sediment on their acute
lethal tolerance to the reference toxicant pentachloro-
phenol.
Effect of prolonged (6-week) exposure of underyearling
Arctic grayling to suspended placer mining sediment on
their acute lethal tolerance to the reference toxicant
pentachlorophenol.
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Figure
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LIST OF FIGURES (cont'd.)
Effect of prolonged (6-week) exposure of underyearling
Arctic grayling to suspended placer mining sediment on
their tolerance to hypoxia in sealed jar bioassays.
Effect of prolonged ( 6-week) exposure of underyearling
Arctic grayling to suspended placer mining sediment on
their time to death in sealed jar bioassays.
Effect of prolonged ( 6-week) exposure of underyearling
Arctic grayling to suspended placer mining sediment on
their upper lethal temperature tolerance.
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ABSTRACT
Mcleay, D. J., G. L. Ennis, I. K. Birtwell, and G. F. Hartman. 1984.
Effects on Arctic grayling (Thymallus arcticus) of prolonged
exposure to Yukon placer mining sediment: a laboratory study.
Canw Tech. Rep. Fish. Aquat. Sci. 1241: 96 p.
The effects on underyearling Arctic grayling (Thymallus arcticus) of
a 6-week exposure to differing strengths of suspended placer mining
sediment was examined under controlled laboratory conditions during
the summer of 1983. Groups of sixty grayling captured from a Yukon
River tributary stream were transferred to eight test streams and
acclimated to laboratory feed and water quality conditions.
Thereafter, sediment collected from the downstream end of a Yukon
placer mine settling pond was introduced continuously to six streams
at a controlled rate in order to expose fish to suspended sediment
concentrations of 100, 300 or 1000 mg·L-1 (two streams per treatment).
Two control streams continued to receive clear ( nonfiltrable
residue < 5IIig·L-1) freshwater. Fish in each stream were fed a
measured ration (7% wt • day-1) of Biodiet, 4-5 times. daily, together
with supplemental feeding of live zooplankton (Daphnia pulex). Water
quality conditions for each stream, including temperature ( 15 ~ 10C),
pH (6.6 ~ 0.1), conductivity (30 ~ 5 umho•cm-1), dissolved oxygen (9.4
~ 0.2 mg·L-1), nonfiltrable residue and turbidity, were monitored
daily.
The survival of fish iri. each stream throughout the 6-week test
period was high (87 -95%) and unaffected by the sediment suspensions.
Fish growth, as monitored by weekly weighings of individual fish, was
decreased slightly ( 6 -10% relative to control fish) but
significantly by 100 and 300 mg·L-1, and more markedly impaired (33%
relative to controls~ by 1000 mg·L-1. The linear distribution of
grayling in each stream was unaffected by the lowest ( 100 mg·L-1)
suspended sediment strength examined; however, the majority of fish
held in each stream containing 300 or 1000 mg•t.""1 sedimen~ were
displaced downstream throUghout the test period.
Feeding response trials were conducted in each stream using live
surface drift (adult fruit flies; Drosophila melanogaster), sub-
surface drift (brine shrimp; Artemia salina) and benthic invertebrates
( tubificid worms). Times to detect and consume surface drift for
naive fish (previously unexposed to sediment) or those held in test
streams for 5 weeks increased progressively with increasing sediment
strengths. All suspended sediment strengths examined increased the
response times relative to those for control fish. For each
respective concentration, naive fish were slower to respond to surface
drift. The majority of naive fish held in 1000 mg·L-1 sediment failed
to accept the surface or sub-surface food types offered. Feeding
trials conducted with grayling offered brine shrimp or tubifex worms
in each test stream after 5 or 6 weeks' sediment exposure indicated
that the feeding activity of fish in 1000 mg·L-1 suspended sediment
was impaired, whereas those reared in 100 or 300 mg·L-1 sediment
responded to these sub-surface food types as quickly as control fish
in clear water.
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The colouration of fish exposed to 300 or 1000 mg·L-1 suspended
sediment was paler than that of controls or those held in 100 mg·L-1
sediment for 6 weeks. Otherwise, the appearance of all sediment exposed
fish (including gross observations of fish gills) was indistinguishable
from that of controls. Biological characteristics determined for fish
groups sampled from each stream after 6 weeks' sediment exposure, in-
cluding condition factor, body moisture content (%), blood hematocrit
(%), blood leucocrit (%) and plasma glucose (mg%), were unchanged from
control values for all sediment strengths examined.
The performance of fish groups sampled from each laboratory stream
upon completion of the 6-week exposure was examined using standardized
acute lethal tolerance tests with the reference toxicant pentachloro-
phenol, sealed jar bioassays (tolerance to hypoxia), and tests for upper
lethal temperature tolerance. Both groups of fish chronically exposed
to the two higher suspended sediment strengths examined (300 or 1000
mg·V·1) showed a decreased tolerance to this reference toxicant, and
decreased times to death (increased oxygen uptake rates) in sealed jar
bioassays. The ability of fish to withstand hypoxia or upper lethal
temperature extremes was unaffected by the prolonged sediment exposures.
It was concluded that, whereas chronic exposure of Arctic grayling
to suspended sediment concentrations < 1000 mg·L-1 may not cause direct
mortalities of fish or impair their respiratory capabilities, suspended
sediment strengths above 100 mg·L-1 causes a number of serious sublethal
effects including impaired feeding ability, reduced growth rates, down-
stream displacement, decreased scope for activity and decreased resist-
ance to other environmental stressors. The environmental relevance of
these findings is discussed.
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RESU~
Mcleay, D. J., G. L. Ennis, I. K. Birtwell, and G. F. Hartman. 1984. Effects
on Arctic grayling (Thymallus arcticus) of prolonged exposure to Yukon
placer mining sediment: a laboratory study. Can. Tech. Rep. Fish. Aquat.
Sci. 1241: 96 p.
Les auteurs ont etudie !'incidence de differentes concentrations de
sediments en suspension provenant d'une exploitation miniere alluviale sur des
ombres arctiques (Thymallus arcticus) de moins d 1 un an. L'exposition a dure
six semaines sous des conditions controlees en laboratoire pendant 1' ete de
1983. Des groupes de 60 ombres captures dans un tributaire du fleuve Yukon
Ont ete transferes danS hui t COUrS d I eau experimentaUX et aCClimateS a la
nourriture de laboratoire et a la qualite de l'eau. Des sedi111.ents recueillis
a la sortie d 'un bassin de sedimentation d 'une exploitation alluviale du Yukon
ont ete introduits continuellement dans six cours d'eau, a un taux controle,
de fa9on a exposer les poissons a des concentrations.de sediments en
suspension de 100, 300 et 1000 mg.L-1 (deux cours d'eau par traitement).
Les deux aut res cours d' eau ont. continue -de recevoir de 1 'eau· douce claire
(residu non filtrable 5 mg.L-1). Tous les poissons ont ete nourris de
rations quantifiees (7% poids. jour -1) de Biodiet quatre a cinq fois par
jour, en plus de zooplancton (Daphnia pulex) vivant. Tous les jours, on a
surveille les facteurs qualitatifs de l'eau y compris la temperature
(15 :t l°C), le pH (6,6 :1: 0,1), la conductivite (30 :1:5 umho.cm-1), !'oxygene
dissous (9,4 :1: 0,2 mg.L-1), les residus non filtrables et la turbidite.
La survie des poissons dans tous les cours d'eau a ete elevee
(87-95%) pendant toute la periode de six semaines et n'a pas souffert des
sediments en suspension. La croissance, controlee par la pesee hebdomadaire
de chaque poisson, a baisse un peu (de 6 a 10% par rapport aux poissons
temoins) mais de fa~on significative, aux concentrations 100 et 300 mg.L-1,
et elle a nettement diminue (33% par rapport aux poissons temoins) a
1000 mg.L-1. La repartition lineaire des ombres dans chaq~e cours d'eau n'a
pas ete alteree par la plus faible concentration de sedimen~s en suspension
(100 mg.L-1); toutefois, la plupart des poissons peuplant les cours d 1 eau
contenant 300 et 1000 mg.L-1 de sediments se sont diriges vers l'aval
pendant toute la periode d'experience.
Des essais sur la reaction a la presence d'aliments ont ete menes
dans chaque cours d'eau a !'aide d'organismes vivants flottant a la surface
(drosophiles adultes, Drosophila melanogaster) et sous la surface (artemias,
Artemia salina) ainsi que d'invertebres benthiques (Tubificides). Le temps de
detection et de consommation des proies de surface par les poissons a 1' etat
naif (encore jamais exposes aux sediments) et par ceux gardes dans les cours
d'eau experimentaux pendant cinq semaines a augmente progressivement en
fonction des concentrations de sediments. Toutes les concentrations etudiees
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ont entratne une augmentation des temps de reaction par rapport a ceux des
poissons temoins. A chaque concentration, les specimens a l'etat na~f
etaient plus lents a reagir aux proies de surface. La plupart de ces poissons
gardes a une concentration de 1000 mg.L-1 n'ont pas mange les p.roies
flottant a la surface ou sous la surface. Les essais d'alimentation a !'aide
d'artemias ou de tubifex, menes dans les cours d'eau experimentaux apres cinq
OU Six SemaineS d I expositiOn a deS SedimentS, }lortent a CrOire que
!'alimentation des poisson8 gardes a une concentration de 1000 mg.L-1 de
sediments en suspension etait alteree tandis que ceux maintenues a des
concentrations de 100 ou 300 mg.L-1 reagissaient aux p.roies p.resentes sous
la surface aussi vite que les poissons temoins gardes en eau claire.
Les poissons exposes a des concentrations de 100 et de 300 mg.L-1
de sediments en suspension etaient plus pales que les temoins ou les poissons
gardes a une concentration de 100 mg.L-1 pendant six semaines. Pour le
res te' tOUtefOiS' 1 I apparence de tOUS leS poiSSODS expoSeS a deS SedimentS (y
compris !'observation superficielle des branchies) n'etait pas differente de
celle des temoins. Les caracteres biologiques (facteur de condition, teneur
en eau (%), hematocrite sanguin (%), leucocrite sanguin (%) et glucose
plasmatique (mg%)) determines chez des groupes de poisson echantillonnes dans
chaque cours d'eau apres six semaines d'exposition a des sediments etainent
semblables aux valeurs temoins a toutes les concentrations de sediments
etudiees.
On a evalue la performance des groupes de poisson echantillonnes
dans chaque cours d'eau experimental apres une exposition de six semaines, a
!'aide de tests de la tolerance letale aigue avec le toxique etalon
pentachlorophenol, de dosages biologiques en milieu ferme (tolerance a
l'hypoxie) et de tests de tolerance de la temperature letale superieure. Les
deux groupes de poisson exposes chroniquement aux deux plus hautes
concentrations de sediments en suspension (300 et 1000 mg.L-1) ont accuse
une tolerance moindre a ce toxique etalon et des temps inferieurs de mortalite
(absorption accrue de !'oxygene) au cours des tests en milieu ferme. La
capacite de resistance des poissons a l'hypoxie ou aux extr@mes de
temperatures letales superieures n'etait pas affectee par !'exposition
prolongee a des sediments.
Selon les auteurs, m~me si !'exposition chronique de l'ombre
arctique a des concentrations de sediments en suspension inferieures ou egales
a 1000 mg.L-1 ne cause pas la mortalite directe des poissons ou n'amoindrit
pas leurs capacites respiratoires, des concentrations superieures a
100 mg.L-1 entra1nent certains effets subletaux importants y compris une
capaci te d' alimentation redui te, des taux de croissance inferieurs, un
deplacement en aval, une capacite diminuee d'activite et une resistance
moindre aux stress environnementaux. Les auteurs parlent aussi de
!'importance environnementale de ces decouvertes.
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INTRODUCTION
Recent field and laboratory studies conducted with underyearling
Arctic grayling (Thymallus arcticus) demonstrated that brief ( ~ 4
days) exposure to elevated levels of suspended placer mining sediment,
while not lethal, caused a number of sublethal effects including acute
stress responses (McLeay et al. 1983). Additionally, reports from a
number of field surveys within Yukon documented a reduction in numbers
of Arctic grayling and other fish species for rece~v~ng waters
downstream of placer mining activities (Mathers et al. 1981; Ennis et
al. 1983; Birtwell et al. 1984). These findings suggest an impact of
placer mining sediment suspensions on the fisheries resource;· however
the nature and extent of effects of sediment strength and duration of
exposure are not clearly understood at this time.
The present investigation was undertaken to gain some under-
standing concerning the effects on Arctic grayling caused by prolonged
exposure to Yukon placer mining sediment. Although information is
limited, reduced survival or impaired growth of salmonid fish species
have been reported caused by their extended exposure to suspended
sediment fines as low as 300 mg·L-1 (Herbert and Merkens 1961; Sigler
1981). · The effects of prolonged sediment exposure on fish
performance, biochemical indices of fish condition, or behavioural
responses have not been reported. However, the need for further
knowledge regarding these and other possible effects caused by chronic
exposure of fish to elevated levels of suspended sediment has been
recently delineated (Noggle 1978; Anon. 1983). · ·
The strengths of suspended placer mining sediment selected for
the present laboratory study (0, 100, 300 and 1000 mg·L-1 nonfiltrable
residue) were chosen based on a number of considerations. Since the
level of suspended sediment in certain placer-mined Yukon streams
frequently remains elevated during summer months to values > 1000
mg·L-1 (Mathers et al. 1981), the impact of this elevation on the
wellbeing of resident grayling fry or fingerlings rearing in these
waters is of concern. Although the adverse effects towards grayling
caused by chronic exposure to suspended sediment are unknown,
suspended sediment strengths > 300 mg·L-1 have been reported to cause
significant mortalities of salmonid fish if exposures are prolonged
(Herbert and Merkens 1961), and strengths .?.. 100 mg·L-1 can cause
reduced feeding activity and lower fish condition factors (Noggle
1978; Scullion and Edwards 1980). Following a review of (then)
current literature, the European Inland Fisheries Advisory Commission
(Anon. 1965) concluded "wate:r:-s normally containing from 80 to 400 ppm
(mg·L-1) suspended solids are unlikely to support good freshwater
fisheries", and "at best, only poor fisheries are likely to be
- 2 -
found in waters which nqrmally contain more than 400 mg·L-1 suspended
solids." Discharge standards of 100 or 1000 mg·L-1 (depending on
stream classification) have been recently proposed for Yukon placer
mining operations (Anon. 1983).
The study described in this report was designed to determine the
effects of three replicate strengths of suspended placer mlnlng
sediment on the feeding behaviour, growth, biological condition and
performance capabilities of underyearling Arctic grayling held in
artificial streams under controlled environmental conditions.
Variables measured to assess fish condition and performance were based
on those shown to be useful in previous assessments of fish exposed to
suspended sediment or other environmental stressors (Noggle 1978;
Wedemeyer and McLeay 1981; McLeay et al. 1983; Wedemeyer et al. 1983).
MATERIALS AND METHODS
TEST FISH
Fish collection
A population of approximately 3000 young-of-the-year Arctic
grayling were collected by pole seine from a Yukon River tributary
stream (Nares Creek; near Carcross, Yukon Territory) during June 1983.
These fish, captured by pole seining, measured 2 - 4 em fork length.
Creekwater temperature at the time of collection varied from 15 to
21oc.
Upon capture, fish were placed in plastic "laundry" baskets lined
with fibreglass mesh screen, covered with plastic sheeting and held in
Nares Creek for up to 48 h until sufficient numbers were collected for
shipment. At this time, groups of 200 -250 individuals were placed
in separate plastic bags (creekwater with an oxygen atmosphere),
packed with ice and shipped by air to Vancouver in twelve "Coleman"
coolers.
Fish rearing
Grayling were transferred to the fish-culturing facilities at
B. C. Research (Vancouver) upon receipt, and placed in an outdoor
fibreglass hatchery trough. Water supply to this rearing trough was
Vancouver City dechlorinated tap water. The water exchange rate was
> 5 L·g-1 fish per day and fish-loading density did not exceed 1 .5
g·L-1 (Sprague 1973) throughout the period that grayling were reared
in this trough.
Fish were fed an excess ration of Biodiet No.1
size; Bioproducts Inc., Warrenton, Oregon) 8
( < 0.6 mm crumble
10 times daily,
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- 3 -
according to accepted hatchery practice (Leitritz and Lewis 1976).
This diet was supplemented with daily feedings of live daphnia
(Daphnia pulex) and weekly feedings of live brineshrimp (Artemia
salina).
Daphnia were reared outdoors in two shallow (15 em) circular (100
em dia) plastic pools. Water supply for culturing daphnia was local
mountain creekwater, transported in 20-L plastic jerricans. The
initial brood stock of daphnia was obtained from the B.C. Ministry of
Environment water quality laboratory. Daphnia were fed twice-weekly
rations of finely homogenized fresh spinach. Water was aerated con-
tinuously and was renewed infrequently. The brine shrimp used for
rearing fish and for feeding behavioural trials with test fish was
purchased as required from a local distributor.
The fish trough was siphoned daily to remove excess food and
faeces. Dead or injured fish were removed upon observation. All fish
selected for prolonged exposure to sediment were acclimated to these
conditions for 3 weeks prior to their transfer to the test streams.
TEST SEDIMENT
Sediment collection
A 275-kg sample of dry sediment was collected by Indian and
Northern Affairs Canada personnel from a Yukon (Highet Creek) placer
mine settling pond in June 1983. This sample was taken from a sur-
ficial 5-cm layer of sediment within the downstream end of a de-
watered settling pond. Preliminary screening of pond sediment with a
50 um mesh screen was undertaken to select the section of the pond
containing the largest percentage of fines.
The sediment was placed in ten (new) 25-L plastic pails with
snap-on lids. This sample was shipped to Vancouver, whereupon it was
mixed throughly and returned to the pails for storage ( 18 -200C)
until required for testing.
Sediment preparation and analyses
Preliminary examination of the sample of settling pond sediment
re-dispersed in freshwater ind~cated rapid re-settling of sediment
particles. Initial trials with this sample stirred in water within
the test apparatus used for the present study confirmed that sample
suspensions with nonfiltrable residue (NFR) values of 100 -1000
mg·L-1 could not be achieved without reduction of particle size.
Accordingly, all portions of the sediment sample used in the bioassays
were pulverized prior to fish exposure. Quantities of sediment re-
quired daily for the 6-week exposure study were oven-dried (500C) to
- 4 -
constant weight, and measured amounts (200 ml ":'250 g) ring-pulverized
according to a procedure used previously for acute exposure studies
with grayling and inorganic placer mining sediment (McLeay et al.
1983).
A 250-g portion of untreated sediment and two 250-g portions of
prepared (pulverized) sediment taken from separate plastic pails were
analysed for particle size distribution. Each sample was wet-sieved,
oven-dried ( 500C) and mechanically agitated for 10 min through a
standard series of Tyler sieves. The percentage weight of sediment
retained on each sieve was calculated (Anon. 1972).
Two sub-samples of prepared sediment were analysed for each of
the following characteristics: oxygen uptake rate, % volatile
residue, % fixed residue, and concentration of inorganic constituents.
The oxygen uptake rate of this sediment at 15oc was determined ac-
cording to a procedure used previously with placer mining sediment
(McLeay et al. 1983). Percentage volatile and fixed residue were
determined according to Standard Methods (Anon. 1979, 1980). Major
and trace inorganic constituents of the sediment were determined by
plasma spectrographic analysis following sample digestion (Anon.
1979).
EXPERIMENTAL
Test apparatus
The experimental set-up used for this study is illustrated in
Figure 1. Basic apparatus consisted of eight test streams, situated
side-by-side and constructed of 6-mm plexiglass sheeting. Each stream
measured 210 X 13 X 20 em and was fitted with a removable screen
partition at the mid-and down-stream positions (at 100 and 200 em
from the head end), a vertical overflow stand-pipe at the downstream
end and horizontal inflow/outflow plastic pipes at each end. The
water (or test suspension of sediment) in each stream was pumped
(Cole-Parmer impeller driven pumps) at 10 L·min-1 through 2-cm ID
plastic tubing. This flow rate maintained an upstream riffle of fast
moving water within the first third of the test stream, and a down-
stream pool of slower-moving water within the latter stream portion.
Oil-free compressed air was introduced continuously to the head-and
mid-stream positions of each stream at a controlled rate. An
emergency oxygen supply (compressed 02 cylinder and regulator with
normally closed solenoid valve) was plumbed into the air supply line
to ensure against the event of a power failure.
Four 220-L capacity rigid polyethylene barrels were used as re-
servoirs for the sediment suspensions. The sediment strength .prepared
daily (using clear freshwater) in each of three barrels was stirred
constantly ( Greey Lightnin motor at 1700 rpm with a stainless steel
shaft and 8-cm dia impeller). One barrel contained clear freshwater
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- 5 -
only (water for control streams). Throughout the 6-week period of
sediment exposure, the contents of each barrel were pumped continu-
ously (Cole-Parmer Masterflex peristaltic pumps) to each of two
streams at a controlled rate of 70 ml•min-1•stream-1. This rate pro~
vided a 95% molecular exchange of each test suspension (and of control
water) within each stream every 24 h (Sprague 1973).
All barrels, pumps, and streams were housed within a temperature-
controlled room, regulated to provide a test temperature within each
stream of 15 .:!: 1oc. Each stream was covered with fibreglass mesh
screening to prevent fish escapements. The test apparatus was
designed and positioned within the room to permit easy access to both
ends of each stream for feeding, cleaning, and fish feeding
behavioural trials.
Lighting to each test stream was provided by four 40-W broad-
spectrum "Vitalite" fluorescent tubes, equally spaced across the
streams. These lights were regulated by timer to maintain a day/night
sequence of 18-h L: 6-h D. Additionally, overhead incandescent 40-W
bulbs, regulated by timer and 30-min automated rheostat control, were
synchronized with the fluorescent lights in order to provide a 30-min
period of variable light intensity at each dawn and dusk. The
intensity of light at the surface of each test stream during daylight
hours was 100.:!: 5 foot-candles (1076.:!: 54 lux).
Treatment of fish
Following a 3-week period for the acclimation of grayling to
laboratory conditions of water and feed, 480 fish selected from the
rearing trough for similar size (mean weight for individuals, 0.4 g)
were placed by random selection into the eight test streams, 60 per
stream. Wet weight of each fish was recorded. Each st~eam contained
clear (nonfiltrable residue < 5 mg·L-1) freshwater only. This water
(Vancouver City dechlorinated· tap water at 15 .:!: 10C) was renewed
continuously by the inflow of fresh water to each stream at a rate
.?,230 ml·min-1 (Appendix 1), providing a 95% exchange every 9 h or
less (Sprague 1973).
Fish in each stream were fed a pe-weighed ration of Biodiet 4 - 5
times daily during an initial 7-day acclimation period in freshwater
and throughout the 6-week sediment exposure period thereafter. The
(excess) ration provided was approximately 7% wet body weight per day
(based on the mean weight of fish in each test stream as derived from
weekly weighings of individual fish), according to the dry food ration
recommended for young salmonid fingerlings (Leitritz and Lewis 1976).
This ration was initially Biodiet No. 1 ( < 0.6 mm crumble size) only,
but was changed to a 50:50 mixture of Biodiet Nos. 1 and 2 (0.6 -0.8
mm) arter 3 weeks and to Biodiet No. 2 only after 6 weeks.
Additionally, fish were fed live daphnia twice daily. The daphnia
were -concentrated ~n glass 'beakers and (approximately) equal
quantities dispensed to each stream by pipeting. This supplemental
- 6 -
ration of live food comprised less than 10% (dry weight basis) of the
total daily food offerings. All food offered (commercial and live)
was dispersed evenly along the length of the stream.
Excess food and fa~ces in each stream were removed daily by
siphoning, and screens cleaned. Arty dead fish noted at this time were
removed, weighed, and examined.
Following a 7-day period for fish to acclimate to these streams,
the freshwater supply to ecich stream was discontinued and individual
fish were re-weighed. Pre-determined strengths of sediment suspen-
sions were then metered continuously from the reservoirs into the test
streams throughout the subsequent 6..:week test period. The nominal
strength of suspended placer mining sediment in each stream to which
grayling were exposed, as assigned by random choice, was as follows:
Stream nos. 4 and
Stream nos. 2 and
Stream nos. 3 and
Stream nos. 1 and
Test strengths of sediment
8:
5:
6:
7:
0 mg·L-1 NFR (control streams);
100 mg·L-1 NFR; .
300 mg•L~1 NFR; and
1000 mg·L-1 NFR
Prior to transferring fi::Jh to the test streams, a preliminary
study was conducted using the test apparatus to ascertain the
strengths of sediment required for addition to each barrel in order to
achieve the desired .suspended .sediment s~rengths ( 0, 100, 300, or 1000
mg·L-1 NFR) within each stream. Pre-weighed strengths of pulverized
placer mining sediment ranging from 300 to 5000 mg·L-1 were made up in
each barrel (220-L volumes) using clear (NFR <5 mg·L-1) Vancouver City
dechlorinated tap water at· 15oc.' Each suspension was pumped into a
separate test stream at the desired flow rate (70 ml·min-1), and
sampies taken from the head-(upstream) and mid-stream positions of
the stream for nonfiltrable residue (NFR) analyses after 22· h of dis-
pensing.·
Based on the .results of this study, it was calculated that
quantities of sediment required daily for preparing each 220-L volume
were 120 g (100 mg·L-1 NFR in streams 2 and 5), 350 g (300 mg·L-1 NFR
in streams 3 and 6), and 1140 g (1000 mg·L-1 NFR in streams 1 and 7).
These quantities were used initially during the definitive study.
However, based on nonfiltrable residue values determined for stream
samples collected daily during the test period, sediment quantities
added to each barrel were increased by 20% after 2 weeks' exposure.
This quantity was again modified slightly at 4 weeks ( 10% reduction).
Vancouver City dechlorinated tap water at 15:t. 1oc was used daily for
preparing each test suspension (and as control water).
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- 7 -
Water quality monitoring
The freshwater supply used for rearing grayling and as the
diluent/control water was analysed weekly throughout the duration of
the study. Water quality characteristics determined (Anon. 1980) for
each sample were as follows: pH, temperature (OC), dissolved oxygen
(mg 02·L-1), conductance (umho·cm-1), alkalinity (mg CaC03·L-1), EDTA
hardness (mg CaC03·L-1), and nonfiltrable residue (mg·L-1).
The water quality in each test stream was monitored daily
throughout the 7-day acclimation period and the subsequent 6-week
exposure period. The following variables were measured mid-stream
(mid-depth, mid-length): temperature (OC), dissolved oxygen (mg
o2 -L-1), pH, conductance (umho·cm-l), nonfiltrable residue (mg·L-1)
and turbidity (formazin turbidity units; FTU). Temperature was
measured by thermometer to the nearest 0. 1 oc. Dissolved oxygen was
determined using a portable oxygen meter (Delta Scientific Model No.
1010). Stream pH was measured using a portable pH meter (Metrohm
Herisan Model No. E488). Water samples were collected daily from each
stream by siphoning from the mid-stream position into clean plastic
bottles. These samples were analysed subsequently for conductance,
nonfiltrable residue and turbidity, using standardized methodologies
(Anon. 1979, 1980). Samples with low turbidity values ( < 25 FTU)
were analysed for turbidity using a ·Hach Model 2100A turbidity meter;
whereas those with higher values were determined using a Jackson
Turbidimeter (APHA, U.S. Geological Survey).
The rate of. inflow of each test suspension (or control water) to
each stream was measured (stopwatch, graduate cylinder) and recorded
daily. Minor adjustments to pumping rates were made as required.
On one occasion (13/08/83), water samples were taken concurrently
from three positions (upstream, mid-and downstream) within each test
stream. Each sample, ,collected by siphoning · at mid-depth, was
analysed for nonfiltrable residue content in order to ascertain the
consistency of suspended sediment strengths along the length of each
stream. ·
Fish.growth
The growth of grayling in each test stream was monitored weekly
throughout the study. At 7-day intervals following their transfer to
streams, all fish in each stream were netted and placed ·in separate
44-L clean glass aquaria. Each aquarium contained the water or
sediment suspension strength to which fish were exposed in test
streams. The dissolved oxygen content of each aquarium water supply
was maintained at > 9 mg 02·L-1 by continuous aeration. Individual
fish in the aquarium· were netted and placed on a top-pan balance
(Oertling Model No. HC22) into a beaker of test water (weight tared
to zero). The weight of each fish was recorded to the nearest 0.01 g.
Care was taken during each weighing to prevent excess carry-over of
water.
- 8 -
Each group of fish from each stream was weighed and returned to
the stream within a 60-min period. During this time, each stream was
cleaned thoroughly and refilled with the test suspension/control
water. Any dead or missing (based on the previous week's count) fish
were noted for each group, and weekly mortalities recorded.
After 3 weeks' sediment exposure, ten fish were sampled randomly
from each stream for assessment of their tolerance to the reference
toxicant pentachlorophenol. The wet weight (g) and fork length (em)
of each of these fish were measured upon termination of the bioassay.
Lengths and weights of each grayling surviving exposure to differing
strengths of placer mining sediment for 6 weeks were also determined
following the completion at this time of each evaluation of fish con-
dition/performance.
Fish behaviour
Due to the opacity. of sediment suspensions, observations of fish
in test streams were restricted to fish movements (surfacing, response
time) discerned during routine feeding. The position of fish in each
stream could also be observed at this time.
On two occasions (after 4 and 5 weeks' sediment exposure), each
stream was partitioned with screens into four equal lengths, just
prior to the removal of fish for weight determinations. The number of
fish occupying each stream portion was determined in order to gain
some information concerning their distribution.
The effect of suspended sediment strength on feeding response
times to live food organisms for grayling held in each test stream for
5 or 6 weeks was ascertained. Separate feeding response trials were
conducted using surface drift food organisms (fruit flies; Drosophila
melanogaster), sub-surface drift (brine shrimp; Artemia salina), or
benthic food organisms (tubificid worms).
Live adult fruit flies were obtained from the Department of
Zoology (Genetics Laboratory), University of British Columbia for the
feeding response trials with surface drift. For each trial, all fish
in each test stream were moved to the upstream half, and a screen
partition inserted to prevent their downstream movement. Three fish
in each stream were netted randomly and placed in the downstream half.
Following a 60-min period for these fish to adjust to this transfer,
the three fish were herded slowly to the most downstream 10-cm section
of the stream using a second soft-mesh screen. A fruit fly was placed
on the stream surface at a point 60 em upstream of these fish, and the
second screen removed (time 0). Time (seconds) for fish to consume
the fly was measured (stopwatch) and recorded. Each test was ter-
minated at 360 seconds (6 min) if flies were uneaten.
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This procedure was replicated 5 -9. times (depending on trial)
using each group of three· fish. Three separate trials with surface
drift were conducted, using different groups of three fish selected
from and tested in each stream for each trial.
Following these feeding response trials with grayling exposed to
susp~nded sediment for 5 weeks, two trials (5 -7 replicates per
trial) were undertaken in each test stream using naive grayling (those
previously unexposed to suspended placer mining sediment) • All test
fish in each stream were moved to" the upstream half, and retained by
screen partition. Naive fish were netted from the outdoor rearing
trough and placed in the downstream half of each test stream, three
fish per stream. Fish were given a 60-min period to adjust to this
transfer. Thereafter, these fish were moved slowly to the most down-
stream 10-cm portion of the stream, and their feeding response to live
fruit flies determined as before.
Feeding response trials with grayling and live sub-surface drift
(brine shrimp) or benthic invertebrates (tubifex worms) were performed
in test streams using submersible baskets. Each basket, measuring 60
X 15 X 15 em, was constructed of white soft-mesh nylon cloth supported
by a rigid framework ( 4 mm stainless steel wire). Baskets were de-
signed to permit observation of the number of sub-surface food
organisms consumed in test streams at fixed time intervals.
The tubifex worms used in feeding trials were obtained locally
from a retail store. For each trial, all fish in each test stream
were moved to the upstream half and screen partitions inserted. Ten
worms were distributed randomly along the length of the bottom of a
basket, and the basket submersed in the downstream portion of a test
stream. Three grayling, selected randomly from the group held up-
stream, were netted and placed in the basket. The bottom of each
basket was raised to just below the stream's surface at fixed time
intervals of 1, 3, 5, 10, 15, 30, 45, and 60 min and the number of
uneaten worms counted. Each observation was performed quickly (5 - 7
sec) and care was taken to ensure that fish were not struggling out of
water at these times. For each test stream, three feeding trials with
worms were conducted in this manner, using different groups of three
fish for each trial. Additionally, one feeding trial with tubifex
worms was carried out in each stream using naive fish selected from
the outdoor rearing tank. These fish were transferred to the pawn-
stream half of each stream (3 fish per stream) and held for 1 h prior
to placing them in baskets. The procedure for testing the feeding
response of naive grayling with tubifex worms was identi~al to that
used for fish held in the test streams for 5 weeks.
Three feeding response trials with live brine shrimp and stream
grayling were conducted in each stream after 6 weeks' exposure of test
fish to sediment suspensions. For each test, ten brine shrimp were
placed randomly in each stream basket, and three fish introduced.
Test procedures for conducting these trials were identical to those
described for the tests with worms. The feeding response of naive
grayling in test streams was not examined using brine shrimp.
-10 -
Fish condition
Following 6 weeks' exposure to sediment suspensions, ten grayling
were sampled from each test stream for assessment of fish condition.
Individual fish were netted, damp-dried, and measured for length (em)
and wet weight (g). The caudal peduncle was severed and blood col-
lected in a narrow-bore (0.5 mm ID) heparinized microhematocrit tube
(Sherwood Industries Ltd., St. Louis). Fish carcasses were weighed
(wet weight) and transferred to a 105oc oven until dried to constant
weight. Body moisture content was determined thereafter. Autopsies
of each group of ten fish were completed within 30 min.
All blood samples were centrifuged (12500 rpm; 3 min). upon
collection. Hematocrit and leucocrit ·values were measured according
to procedures described previously (McLeay and Gordon 1977; McLeay et
al. 1983). Plasma portions remaining following centrifugation were
stored ( -200C) until analysed for glucose content (Beckman Glucose
Analyser 2).
The condition factor of each fish was calculated (based on fish
fork length and wet weight). Fish condition factors were also
determined for all fish sampled from test streams for assessments of
fish performance after 3 and 6 weeks' exposure to placer mining
sediment.
Fish performance
The acute lethal tolerance of test fish to the reference toxicant
pentachlorophenol (Davis and Hoos 1975; McLeay et al. 1983) was
determined following their exposure to sediment suspensions for 3 or 6
weeks. These bioassays were conducted using eight 50-L capacity
plexiglass aquaria. At the time of each bioassay, identical volumes
(25 L at 3 weeks, 40 .L at 6 weeks) of a 150 ug·L-1 solution of
pentachlorophenol dissolved in clear freshwater ( 15oc dechlorinated
tap water; NFR < 5 mg·L-1) were prepared (Alderdice 1963; McLeay et al.
1983) and added to each aquarium. Ten fish, selected randomly from
each test stream, were placed in each aquarium. The time to death of
each fish was measured and recorded. Upon death, each fish was
removed from the aquarium and its length and weight determined.
The effect of exposure of grayling to sediment suspensions for 6
weeks on fish respiration was assessed by sealed jar bioassay. Test
procedures ( McLeay 1976; Gordon and McLeay 1977) were those used for
evaluating the respiratory responses of naive (previously unexposed)
grayling to placer mining sediment (McLeay et al. 1983). Following
the 6-week exposure perlod, b-L volumes of test suspensions (or
control water) from each of the eight test streams were heated to 2ooc
(test temperature) and aerated vigorously for 30 min to ensure oxygen
saturation. Dissolved oxygen values were measured and each suspension
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-11 -
transferred to ten 140-ml clean glass jars. Ten test fish, selected
from each stream for similar size ( I\./ 1. 3 g) were placed in these
jars, one fish per jar. Each jar was then filled with the appropriate
test suspension and sealed (plastic lid) to exclude air. Upon the
death of each fish, t~me to death, water temperature, and fish length
and weight were recorded. The residual dissolved oxygen level in each
suspension was measured using a portable oxygen meter (Delta
Scientific Model 1010) with mechanical agitator.
The effect of prolonged (6-week) exposure of grayling to
suspended sediment on their upper lethal temperature tolerance was
evaluated by critical thermal maxima bioassays (McLeay and Howard
1977; McLeay and Gordon 1980). The apparatus and procedures used for
these bioassays were identical to those employed previously with naive
grayling and differing strengths of suspended inorganic sediment
(McLeay et al. 1983) ·~ A 50-L volume of each test suspension or
control water was collected (as 4 sub-samples of 13 L each) from each
test stream and placed in each of eight rectangular plexiglass tanks.
Each suspension (or control water) was recycled from the conical
bottom of the tank at 10 L•_min-1 (McLeay et al. 1983). Each tank was
lined with a soft-mesh nylon basket.
All remaining grayling (8 17) in each test stream were
transferred to the appropriate recycle tank. Water temperature in
each tank was initially 15.:!:. 0.1oc. This temperature Wc;iS increased
progressively at a controlled rate of 10C·h-1 (thermostatically-
controlled immersion heaters) until all fish in each tank were dead.
Baskets were raised at frequent intervals to permit observation of
dying/dead fish. The temperature ( ± 0.10C) of each test suspension
was recorded at the time of death of each fish. Upon death, each fish
was removed for length and weight determinations.
Statistical analyses
The condition factor ( K) of test fish after 3 and 6 weeks'
exposure to differing sediment strengths was determined as follows: K
= cW·L-3 where c is a constant ( 100), W is wet weight (g) and L
represents fork length in em (Carlander 1969). Mean and standard
deviation (SD) values for fish length, weight, and condition factor
were calculated for each fish group. Mean ± SD wet weights for all
fish in each test stream, as determined weekly throughout the study,
were also calculated. Additionally, mean ± SD values for all other
variables determined for groups of grayling during the feeding trials
and tests for assessment of fish condition and performance were
determined. Mean + SD values for each water quality characteristic
monitored daily for-each stream throughout the 6-week test period were
also calculated.
For certain values shown graphically, the 95% confidence interval
( CI) for each mean was determined. Mean weekly fish weights for each
of the four sediment treatments were calculated together with their
95% confidence intervals after 6 weeks' sediment exposure.
-12 -
Lethal times to death of 50% (LT50 values) of each group of ten
grayling exposed to the reference toxicant pentachlorophenol or
examined for performance in sealed jar bioassays were calculated,
together _with their 95% confidence intervals, by log-probit analyses
(Litchfield 1949). Provided that the median reaction times for
replicate treatments did not differ significantly (Litchfield 1949),
LT50 values for each treatment ( n=20) were determined and examined for
significance of difference from corresponding values for control fish,
according to Litchfield (1949).
Fish weights determined weekly for each test stream were compared
at each time interval using a 1-way analysis of variance (ANOVA).
Values derived for identical treatments were pooled. For all
comparisons where a significant difference in ANOVA was found
(P <0.05), Dunnett's test (Zar 1974) was employed to test for
significance of each treatment versus the control group. Values
derived for residual oxygen levels at death (sealed jar bioassays) and
upper lethal temperatures at death (temperature tolerance tests)
following a 6-week exposure of grayling to differing sediment
strengths were also compared in this manner.
RESULTS
SEDIMENT CHARACTERISTICS AND DISPERSAL
Particle size distributions for the samples of untreated or
prepared (pulverized) settling pond sediment analysed for this study
are presented in Table 1. Analysis of the untreated test sediment (as
sampled from the settling pond) indicated that the majority (62%) of
material present was fine to very fine sand ( > 45 urn), and only 23% of
the sample was comprised of silt-or clay-sized sediment fines ( < 38
um). Unlike this sample, each of the samples of prepared (test)
sediment analysed was comprised of 70. -71% silt or clay rna terial ( < 38
urn) (Table 1). Particle sizes for all but 2 -3% of each of these
samples were < 75 um.
Volatile/fixed residue content and oxygen uptake rate (in
freshwater at 150C) for replicate samples of the test sediment are
given in Table 2. The values derived for oxygen uptake rate are
identical to those found previously for inorganic placer mining
sediment (McLeay et ai. 1983), and are indicative of an inert sediment
with little, if any, oxygen demand. The residue analyses (Table 2)
support this observation, inasmuch as only 4 -5% of the test sediment
was comprised of volatile (organic) material.
Results from the plasma scan analysis of two samples of the test
sediment for metal content are given in Table 3. As with the other
sediment characteristics examined, the concentrations of specific
metal constituents in each sample were very similar (i.e. the
characteristics analysed for different portions of the test sediment
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were homogeneous). These values are presented for purposes of sample
"fingerprinting" only. Strengths of specific metals dissolved in
freshwater suspensions of the test sediment (and conceivably
biologically available) were not analysed in this study.
The relationship of sediment strengths in the barrel reservoirs
to those mantained in suspension within the test streams is
illustrated in Figure 2. This relationship was linear with respect to
concentration; i.e. for all concentrations examined the sediment
strengths made up in the barrel reservoirs were approximately five
times the nonfiltrable residue values measured in the test streams.
Results in Figure 2 and those in Table 4 indicate that stream
position (horizontal distribution) did not affect the suspended
sediment strength. Non-filtrable residue values for water samples
taken concurrently from upstream, mid-or downstream positions did not
differ appreciably for any of the test strengths examined. The
vertical or cross-stream distribution of suspended sediment strengths
within the test streams were not examined.
WATER QUALITY
Mean .:!:. SD values for the freshwater supply, as determined from
grab samples taken weekly ;following the receipt of test fish, were as
follows: temperature 15 ~ 0.5oc, pH 6.6 ~ 0.1, dissolved oxygen 9.3 ~
0.2 mg·L-1, conductance 26 ~ 4 umho•cm-1, alkalinity 1.8 ~ 0.6 mg·L-1,
EDTA hardness 4.1 ~ 0.2 mg·L-1, and nonfiltrable residue < 5 mg·L-1.
Water quality characteristics determined daily for each test
stream throughout the 7-day acclimation period and the subsequent 6-
week exposure period are given in Appendix 1 and summarized in Table
5. Daily fluctuations in stream NFR and turbidity values are
illustrated in Figures 3 and 4, respectively.
The rate of inflow of fresh suspensions of sediment or control
water to each test stream was nearly constant throughout the exposure
period (Appendix 1), and did not differ appreciably between streams
(Table 5). Mean water temperatures for streams 1 - 7 were similar and
did not vary greatly during the study. However, the temperature for
stream 8 (control stream) water was consistently less than that for
all other streams (mean value 0.9 -1.6oc lower; Table 5). Dissolved
oxygen values for all. stream samples were ~0% air saturation (~ 8.8
mg 02·L-1), and were unaffected by sediment treatment. Mean pH values
for each stream were similar (6.5 -6.7). The conductivity (ionic
strength) of streamwater was increased slightly but consistently due
to the higher sediment strengths (300 and 1000 mg·L-1), with mean
daily values of 30 or 36 UIJh'J.o~ cm-1 respectively (control water 25
umho·cm -1) (Table 5).
-14 -
Nonfiltrable residue values for the control water (streams 4 and
8) were consistently below the limit of detection ( < 5 mg·L-1). Mean
NFR values for streams 2 and 5 (nominal strength, 100 mg·L-1) were 86
and 93 mg·L-1 respectively, with mean values of 286 or 273 mg·L-1
(streams 3 and 6) and 988 or 955 mg·L-1 (streams 1 and 7) for nominal
suspended sediment strengths of 300 or 1000 mg·L-1. The NFR values
measured daily for each of these test streams varied somewhat, with
slightlY, higher values for each respective stream evident during the
third and fourth weeks of exposure (Fig. 3, Appendix 1). However, no
overlaps of any NFR values occurred between the differing sediment
treatments employed (100, 300 or 1000 mg·L-1).
As with stream NFR, daily and mean turbidity values for identical
treatments were similar (Fig. 4, Table 5). Turbidity values for all
samples of clear (control) freshwater analysed were < 3 FTU. The
pattern of daily fluctuations in turbidity values for grayling exposed
to 100, 300 or 1000 mg·L-1 suspended sediment was similar to that
noted previously for NFR values (see Fig. 3 and 4).
FISH SURVIVAL AND GROWTH
All . of the sixty fish. placed in each of the eight test streams
survived the initial 7 -day acclimation period following their
transfer. Thereafter, dead fish were found occasionally in each
stream during the subsequent 6-week test period. These deaths
occurred randomly and were unrelated to sediment treatment (Table 6).
The majority (68%) of dead. fish were found during the initial 2-week
test period. Overall, 8% of the test fish died or were unaccounted
for (presumed to be dead) during the 6-week test period (Table 6).
Examination of the dead fish indicated that 77% (20 of 26) had
lacerations to the abdominal region or to the dorsal body region
immediately posterior to the opercula. The six remaining dead fish
appeared normal or were sufficiently decomposed to prevent the
detection of these injuries. The gross examination of gill tissue for
each dead fish showed no signs of clubbing, accumulation of sediment
particles, or excessiv.e mucous production. All moribund fish observed
in clear water (controls) showed evidence of physical injury (nips or
tears), and aggressive fish interactions resulting in deaths of
otherwise healthy fish were noted on two occasions. Similarly, a high
percentage of fish deaths found for the stock population of grayling
reared in the outdoor trough were caused by excessive fish aggression.
The initial mean weights (and standard deviations) for each group
of sixty grayling transferred to the test streams were nearly
identical (Table 7). Weight gains during the initial 7-day period of
acclimation to each stream (clear freshwater only) were also similar
and were substantial (increases of approximately 25%). Differences in
fish weights due to treatment were not apparent after 1 or 2 weeks'
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exposure to any sediment strength. However, for each of the
subsequent exposure periods examined, the mean weights of each group
of control fish were greater than those for any sediment treatment
(Table 7). Reduced growth due to sediment exposure was concentration-
dependent.
The average percentage weight= gain experienced for each treatment
during the test period was as follows (based on differences in mean
weights of fish at 0 vs. 6 weeks' exposure; Table 7):
0
100
300
1000
mg·L-1
mg·L-1
mg·L-1
mg·L-1
241 % increase
227 % increase
217 % increase
161 % increase
Relative to the control values, there was a 33, 10, and 6% reduction
in growth of fish exposed to 1000, 300 and 100 mg• L-1 suspended
sediment, respectively.
The analysis of variance of weekly fish weights showed that the
differences in variances due to sediment treatment were significant
(P < 0.05) at 2 weeks; and highly significant (P <0.01) after 3, 4, 5,
and 6 weeks' sediment exposure. Dunnett's test for significance (Zar
1974) indicated that weights for fish exposed to the highest sediment
strength examined (1000 mg·L-1) were decreased significantly from
respective values for control fish at 2, 3, 4, 5, and 6 weeks.
Corresponding weights for fish exposed to 100 and 300 mg·L-1 sediment
were depressed significantly from control values after 3, 4, and 5
weeks' sediment exposure. Differences between values-for these lower
sediment strengths and controls did not differ statistically ·following
6 weeks' exposure.
FISH BEHAVIOUR
Distribution in streams
Routine daily observations of fish surfacing to feed in each test
stream indicated that those held in the higher sediment strengths (300
and 1000 mg·L-1) were usually distributed in the downstream half.
Unlike these observations, grayling held in clear freshwater or in 100
mg·L-1 sediment were distributed along the length of the stream,
feeding actively in the upstream half as well as the downstream
portion. This pattern of fish distribution was evident within 1 hour
of the initial introduction of sea1ment to test streams and,
thereafter, throughout the 6-week expo~ure period. With the exception
-16 -
of these periods of feeding; surfacing of fish in the test streams was
not observed. Other observations of fish behavioural responses (i.e.
coughing, threats, nips, swimming activity) could not be made due to
the opacity of all test suspensions examined.
The percentage distribution of grayling in each quarter of each
test stream, after 4 and 5 weeks' exposure to placer mining sediment,
is shown in Table 8. Fish distributions during these periods of
observation were unaffected by feeding activity since no food was
offered on each day prior to the determinations of fish distribution
(and weight).
For the control streams and those containing 100 mg·L-1 sediment,
the distribution of fish in each stream quarter appeared to be
somewhat random and unaffected by sediment treatment. The average
distribution of fish in the upstream and downstream halves of these
test streams was approximately equal although the majority of fish
(62%) were found within the second and third quarters. Unlike this
finding, the average percentage distribution of fish in the downstream
half (third and ·four quarters) of each stream containing 300 or 1000
mg·L-1 suspended sediment was 80 -91% (Table 8). These data,
together with the subjective observations of fish distribution during
routine feeding, indicate that the majority of test fish were
displaced downstream by the higher strengths of suspended sediment
(300 and 100 mg·L-1).
Feeding response trials
For each of the three feeding response trials conducted with
grayling using live surface drift (Drosophila melanogaster), the rate
of response to fruit flies for fish in each clearwater (control)
stream was similar (mean values, 6 - 8 sec) (Table 9). Mean response
times were increased consistently by all sediment strengths examined
including 100 mg·L-1. Response times increased progressively with
increasing suspended sediment strength (Table 9, Fig. 6). In all but
three of the 45 separate tests conducted with the highest sediment
strength (streams 1 and 7), the fruit fly was consumed within the 360-
second test period (Table 9). Mis-strikes (failed feeding attempts)
were noted frequently for fish reared and tested in 300 and 1000
mg·L-1 sediment but were not observed for those held in clear water or
100 mg·L-1 sediment.
The increased response times to surface drift measured in these
controlled feeding trials were consistent with observations made
during the routine (daily) feedings with commercial ration (Biodiet).
At these times, control fish in each stream surfaced and initiated
feeding activity more rapidly than those held in 100 mg·L-1 or higher
suspensions. Lag times pr•ior to initiation of feeding were
consistently longest for fish held in 1000 mg·L-1 sediment.
Differences in response times for fish reared in 100 vs. 300 mg·L-1
could not be discerned.
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The feeding response times to surface drift for naive grayling
(those held in test streams for 1 h prior to testing) are given in
Table 9 and illustrated in Figure 6. In these trials, the response of
control fish was somewhat more variable than that noted previously for
acclimated fish (Table 9), with mean values of 10 -25 seconds. Mean
response times were agaiq increased due to increasing strength of
suspended sediment (Fig. 6). For each respective sediment exposure,
mean response times were similar but appreciably longer than those
recorded previously for grayling reared in test s~earqs for 5 weeks
prior to evaluation. Failure to feed was noted for 18 of the 24 tests
with naive fish held in 1000 mg•L -1 sediment, and for 3 or 6
(respectively) of the 24 tests with naive fish held in 100 or 300 mg•L
-1 sediment (Table 10). Feeding mis-strikes were noted for fish held
in the higher sediment strengths, but were less frequent than those
observed in the previous feeding trials.
The feeding response of grayling to sub-surface drift (live brine
shrimp) following 6 weeks' exposure to differing strengths of
suspended sediment is given in Table 11 and summarized in Figure 7.
For each of the three trials conducted, the response times for
identical treatments were similar. No consistent differences in
response to sub-surface drift were found for groups of fish reared and
tested in 0, 100, or 300 mg·L-1 sediment (Table 11, Fig. 7) Mean
times for consumption of all brine shrimp offered were 3 - 8 min.
Unlike these findings, times to consumption of brine shrimp were
increased due to 1000 mg·L-1 sediment. Test fish held in this
sediment strength consistently failed to consume all of the brine
shrimp offered within the 60-min test period (Table 11).
Suspended sediment strengths of 100 and 300 mg·L-1 did not affect
the feeding response times for grayling held in test streams for 5
weeks or 1 hour and fed live tubificid worms (Table 12). Irrespective
of the length of previous exposure, mean response times for
consumption of all worms by control fish or those held in 100 or 300
mg·L-1 sediment were 3 -10 min, and no consistent changes in response
due to treatment were observed (Fig. 8). However, the highest
sediment strength examined (1000 mg·L-1) inhibited the feeding
response of naive or previously exposed fish to these benthic
invertebrates, with 0 -10% worms consumed in any test during the 60-
min period.
CORDITIOH OF FISH
General
Inspection of grayling sampled from each test stream after 3 or 6
weeks in differing strengths of placer mining sediment .revealed no
overt signs of disease or damage attributable to these sediment
exposures. A small but consistent incidence ( <5%) of fish with
spinal deformities (crinklebacks) became evident in each stream
-18 -
(including control streams) during the test period. However, no body
lesions were evident. Fins and opercula of all fish appeared normal,
and no internal or external hemorrhages were observed. Gross
examination of the gills of each fish showed no signs of clubbing,
discolouration, excess mucous production, or adhesion of sediment
particles.
All fish sampled from the highest strength of sediment tested
( 1000 mg·L-1) were notably paler than control fish, and parr marks
were indistinct. Those held in 300 mg·L-1 sediment were only slightly
paler than fish reared in clear freshwater. No differences in
appearance were discerned for fish reared in 100 mg·L-1 sediment vs.
control water.
Fish length and condition factor
Mean condition factors (100 W·L-3) for all fish sampled from each
stream after 3 or 6 weeks' sediment exposure differed randomly and
were not affected by treatment (Table 13). Mean values varied from
0.81 to 0.96; standard deviations for each sample were similar (Table
13).
Mean lengths (and weights) determined for the group of ten fish
sampled from each stream after 3 weeks' exposure to placer mining
sediment were not considered to be representative of overall stream
values due to the smail sample size. Mean fork lengths for all groups
of sediment-exposed fish sampled at 6 weeks (n = 42-47) were
consistently smaller than this value for either group of control fish,
with greatest differences noted between lengths for controls and those
exposed to 1000 mg·L-1 sediment (Table 13).
Biological characteristics
The biological characteristics determined for each group of ten
grayling sampled from each stream after 6 weeks' sediment exposure are
given 1n Table 14. The mean percentage body moisture content for fish
from each stream was similar (77 -79%) and apparently unaffected by
sediment treatment. Hematocrit and leucocrit values for fish were
also unchanged by prolonged exposure to any sediment strength (Table
14). Mean plasma glucose values for each sample were consistently low
(58 -68 mg%) with no consistent changes in magnitude or sample
variance caused by any of these sediment strengths.
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PERFORMANCE OF FISH
Tolerance to reference toxicant
Data concerning the acute lethal tolerance of test fish to penta-
chlorophenol, following a 3-week exposure to differing strengths of
suspended sediment, are given in Table 15 and illustrated in Figure 9.
Based on these median time-to-death (LT50) values, grayling reared for
3 weeks in the lowest strength of sediment examined ( 100 mg·L-1) were
more tolerant to this reference toxicant than the control fish or
those held in the higher sediment strengths (300 and 1000 mg·L-1).
Response times for identical treatments did not differ significantly
for any comparison. However, times to death for all fish reared in
100 mg·L-1 sediment were significantly (P < 0.05) longer than those for
control fish or grayling reared in 1000 mg·L-1 sediment.
After 6 weeks' exposure to sediment, the tolerance to
pentachlorophenol for both control groups and fish reared in 100
mg·L-1 sediment was similarly high (Table 16, Fig. 10). Unlike these
values, times to death in pentachlorophenol for fish reared in 300 or
1000 mg·L-1 sediment were consistently and appreciably shorter.
Statistical analyses (Litchfield 1949) indicated that response times
for streams receiving identical treatments did not differ (P >O .05),
whereas values for fish held in 300 or 1000 mg·L-1 were significantly
lower than those for controls. These results indicate that the acute
lethal tolerance of grayling to this reference toxicant was depressed
by prolonged exposure to these higher strengths of suspended sediment.
Respiration
Findings from the sealed jar bioassays indicate that the short-
term capacity of grayling to withstand hypoxic conditions was
unaffected by their prolonged exposure to sediment. Mean residual
dissolved oxygen values derived for fish from streams rece1v1ng
identical treatments were somewhat variable and showed no consistent
change with respect to sediment strength (Table 17, Fig. 11). Addi-
tionally, the 95% confidence intervals for differing treatments showed
considerable overlap (Fig. 11).
Unlike these findings, times to death of fish exposed to 300 or
1000 mg·L-1 sediment in these sealed jar bioassays (and for 6 weeks in
test streams) were decreased consistently relative to corresponding
values for control fish or those held in 100 mg·L-1 sediment (Table
17, Fig. 12). These declines proved significant (Table 17), whereas
values derived for fish from separate streams receiving identical
treatment did not differ (P >0.05) for any comparison.
Based on mean fish weights; times to death, and residual
dissolved oxygen values at death of fish in sealed jars after 6 weeks'
sediment exposure, oxygen uptake rates (mg 02•g fish-1-h-1) were
calculated for each group of ten fish from each test stream. Results
obtained were as follows:
-20 -
Sediment Stream Oxygen uptake rate
strength no. (mg o2·g fish-1·h-1)
( mg·L-1)
0 4 2.1
0 8 2.2
100 2 2.1
100 5 2.2
300 3 2.3
300 6 2.3
1000 1 2.5
1000 7 2.5
These results show an increase in oxygen consumption rates for each
group of fish exposed to the two higher strengths of suspended
sediment only.
Temperature tolerance
Upper lethal temperatures (mean .:!: SD) for test grayling held in
differing suspended sediment strengths following their 6-week exposure
are given in Table 18. Mean temperatures at death for fish from each
stream, together with their 95% confidence intervals, are depicted in
Figure 13.
The mean temperature at death for fish from one control stream
(stream 4) was similar to values for ail groups of fish exposed to
placer mining sediment (27. 7 -28 .ooc). The 95% confidence intervals
for these groups were similarly small (Fig. 13). However, the mean
temperature at death for the second control group (stream 8) was
notably lower (27.00C) and its 95% confidence interval expanded.
Analysis of variance indicated that differences in lethal temperatures
between treatments were significant (P <O .01). Additionally, pooled
values for each sediment treatment differed significantly from those
from the pooled control value according to Dunnett's test (Zar 1974).
Mean temperatures of acclimation for fish from each stream during
the 6-week period of sediment exposure are also presented in Table 18.
The acclimation temperature for stream-4 fish ( 15.20C) was consistent
with those for fish held for 6 weeks in differing sediment strengths
(14.9-15.6°C), whereas controls reared in stream 8 were acclimated
to somewhat cooler (14.00C) water.
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DISCUSSION
SEDIMENT DISPERSAL/COHCENTRATIOH IH TEST STREAMS
Based on daily observations during cleaning/refilling of the
sediment suspensions in each barrel reservoir, little if any
settlement of sediment occurred w1J~hin these barrels. Thus the 5-fold
difference between sediment strengths in barrels and nonfiltrable
residue values in test streams (Fig. 2) was due primarily to the set-
tlement of larger-sized sediment particles on the stream bottom. This
conclusion is consistent with the observation of a concentration -
dependent buildup of packed sediment < 2 em in depth on the bottom of
each stream during the. weekly cleaning periods. k portion of the
sediment suspended in test strengths may also have passed through the
0. 45 urn filter upon analysis (and therefore not have contributed to
the NFR values derived). However, based on previous analyses of sus-
pensions of similar inorganic sediment for both nonfiltrable and total
residue content (McLeay et al. 1983), the contribution of test
sediment to this filtrable portion of stream water would likely have
been minimal.
Although the vertical or cross-stream gradients of suspended
sediment within each test stream were not examined, it is thought that
the relatively shallow depth and narrow width of each stream, together
with the rapid rate of mixing and recycling of each test suspension,
would have negated any marked stream gradients. The visual inspection
of surface and sub-surface grab samples of water from a number of
positions within each test stream supported this conclusion.
Additionally, stream-length gradients of differing suspended sediment
strength were not apparent (Table 4, Fig. 2).
The daily variations in nonfiltrable residue and turbidity values
determined for each test stream (Figs. 3 and 4) are due to a number of
variables including minor mod.ifications to the amount of sediment
added to the barrel reservoirs at 2 and 4 weeks, unknown experimental
error, and errors in precision of the analytical techniques (Anon.
1979, 1980). Despite these inherent/experimental errors, suspended
sediment strength and turbidity for each test stream were reasonably
constant throughout the 6-week exposure period, and mean nonfiltrable
residue values for streams . to which test fish were exposed
approximated (albeit values were 1 15% lower) the desired
concentrations of 100, 300 or 1000 mg·L-1 (Table 5). Relative to
daily. (or hourly) changes in turbidity or suspended sediment strength
for streams receiving discharges from placer mining activities (McLeay
et al. 1983), the variations for these variables recorded in th~
present study are minor. Additionally, the control/diluent water
remained clear (NFR < 5 mg·L-1, turbidity< 3 FTU) throughout the study
period.
-22 -
FISH SURVIVAL AND GROWTH
With th~ exception of the suspended sediment loadings, water
quality within all test streams was compatible with fish survival and
near optimum for growth of grayling. Freshwaters with dissolved
oxygen values > 90% saturation are not restrictive in terms of the
condition and performance of cold-water fish species (Davis 1975), and
stream pH values of 6.5 -6. 7 are considered within the range of
normal values. Although the optimum temperature for growth of Arctic
grayling has not been defined, the test temperature of 15oc approaches
the physiological optimum determined for other juvenile salmonid fish
species (Brett et al. 1969; Brett 1971). The minor increase in stream
conductivity due to the highest sediment strength examined would not
cause any osmotic stress to test fish; however, the impact of specific
(unmeasured) ions leached from the sediment on fish growth and well-
being cannot be ascertained from the present study. Water currents in
test streams did not cause undue energy·demands.
The present findings indicate that prolonged (6-week) exposure of
underyearling Arctic grayling to strengths of suspended placer mm.ng
sediment <1000 mg·L-1, under otherwise optimal water quality condi-
tions inclUding the readily available excess food, does not affect
fish survival. These findings are consistent with our previous
(McLeay et al. 1983) observations for grayling held in suspended
sediment strengths 50000 mg·L-1 for 2 weeks or less, and with
earlier (Griffin 1938, Herbert and Richards 1963) reports of survival
of rainbow trout (Salmo gairdneri) or Pacific salmon fingerlings
exposed to suspended sediment strengths ranging from 200 to 750 mg·L-1
for several weeks or months. On the other hand, suspensions of
natural sediments in the range of 1000 -2500 mg·V-1 have been
reported to cause deaths of young salmonid fish within 3 weeks or less
(Campbell 1954; Noggle 1978). The European Inland Fisheries Advisory
Commission (Anon. 1965) reviewed these and other findings of fish
death or survival in sediment suspensions, and attributed the diverse
results to differences in sediment particle size, angularity or hard-
ness.
The significant reduction in the growth of grayling exposed to
100, 300 or 1000 mg·L-1 suspended placer mining sediment for periods
of 3 to 6 weeks are consistent with previous findings for growth
studies with sediment-exposed salmonid fish. Herbert and Richards
(1963) reported growth impairment for rainbow trout reared for 33 -40
weeks in suspensions of coal-washery waste or wood fibre as low as 50
mg·L-1. Similarly, Sigler ( 1981) found reduced growth for
underyearling steelhead trout (~ gairdneri) or coho salmon
(Oncorhynchus kisutch) held for 2 weeks in laboratory streams
containing suspended clay solids with turbidity values of 40 -60 NTU.
Depending on the nature and availability of the food supply, settled
sediment fines may also con.strict the growth of stream-reared fish
(Crouse et al. 1981).
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Unlike the findings for grayling in test streams rece1v1ng 1000
mg·L-1 suspended sediment, those reared in 100 or 300 mg·L-1 sediment
grew nearly as well as the control fish. However, these fish were
presented with an abundant supply of food throughout the test period.
Based on the findings from the feeding response trials with live food
organisms, it is thought that these lower suspended sediment
strengths, if present within natural streams for extended periods of
time, could result in a greater impairment of fish growth than was
observed here.
FISH DISTRIBUTION
Since the predominantly downstream distribution of grayling
exposed to the higher suspended sediment strengths (300 and 1000
mg·L-1) was observed within one hour of the initial establishment of
the sediment gradients, it is unlikely that this behavioural response
was caused by movement downstream in search of food. Rather, these
findings suggest an innate downstream movement of these fish in
response to sediment exposure.
Sigler ( 1981) found downstream displacement of steelhead trout
and coho salmon fry from artificial streams receiving clay suspensions
with turbidity values of 40 50 NTU. Noggle (1978) reported
avoidance responses for juvenile coho salmon exposed to suspended
sediment strengths of 4000 -8000 mg·L-1, whereas lower strengths
(1000 -4000 mg·L-1) caused preference responses (fish attraction).
Other investigators have reported no response ( Gradall and Swenson
1982), preference (cited in Noggle 1978) or avoidance reactions (Anon.
1965) for other species of salmonid fish exposed to · low-to-medium
( <1000 mg·L-1) strengths of suspended sediment under controlled
conditions. Berg (1982) determined that short-term pulses of
suspended sediment with turbidity values ..$_60 NTU caused a breakdown
of social organization for juvenile coho salmon in laboratory stream
environments, resulting in increased activity and a loss of aggressive
interactions. From the foregoing, it is apparent that the behavioural
responses of stream fish to suspended sediment are, as yet, unclear;
and that differences in fish species, age, and sediment strength and
type (particle size and shape) may result in diverse behavioural
reactions.
Fish distribution in natural stream environment:;3 c~n be II~firkedly
affected by suspended sediment loadings. Several instances of
salmonid or other fish species avoiding muddy streamwater have been
reported (Anon. 1965). Herbert et al. (1961) reported an absence of
brown trout · (Salmo trutta) fry from downstream sites for streams
receiving china-clay wastes; whereas these fish were abundant at up-
stream, clearwater sites. Similarly, Birtwell et al. (1984) recently
found a consistent reduction in numbers of juvenile Arctic grayling
within downstream water receiving suspensions of placer mining
sediment, relative to numbers found in upstream creekwater or clear-
water tributary streams. These findings provide evidence for a
displacement of juvenile Arctic grayling or other salmonid fish
species from stream environments caused by high suspended sediment
loadings.
: 24 -
FEEDING BEHAVIOUR OF FISH
As with other salmonid fish species, the feeding habits of Arctic
grayling yary depending on life stage. Underyearling grayling feed
primarily on zooplankton or drift from benthic invertebrate larvae,
whereas larger juveniles ( > 13 em) or adult grayling tend to feed on
benthic or emergent insects and larger terrestrial insect drift
(O'Brien et al. 1979; Schmidt and O'Brien 1982; Birtwell et al. 1984).
An examination of stomach contents for underyearling grayling captured
during summer months from clearwater Yukon streams indicated that
these fish were feeding principally on aquatic invertebrate drift
(Chironomidae, Simuliidae) (Birtwell et al. 1984) •
. Schmidt and O'Brien ( 1982) determined that the reactive distance
of Arctic grayling (i.e. distance within which a positive feeding
response occurred) to a number of live zooplankton species was
increased with increasing light intensity. Although several salmonid
fish species appear to reach their maximum visual acuity at ·a light
intensity of about 100 lux (Schmidt and O'Brien 1982), these investi-
gators found that reactive distances for grayling increased up to a
iight intensity of 20000 lux. Based on these findings, these authors
concluded "Because grayling, at least in the Arctic, may do much of
their feeding under conditions of continuous daylight and very clear
water, (genetic) selection for ·low light vision may be low." Our
findings from feeding response trials with Arctic grayling and live
food organisms support this previous evidence that grayling rely on
visual cues to locate insects, and that decreased light intensity (due
in this instance to suspended solids) will impair feeding responses
for this fish species.
Present results indicate clearly that a 1000 mg·L-1 suspension of
placer mining sediment markedly impairs the feeding performance of
underyearling grayling offered surface drift, sub-surface drift or
benthic invertebrates. This impaired response is evident for both
naive fish and those exposed continuously to this suspended sediment
stength for 5 or 6 weeks. Interpretation of the effects noted for
fish held in the lower sediment strengths (100 or 300 mg·L-1) are less
clear and confounded by modifications in the experimental approach
used with differing food organisms. The increase in time to respond
to surface drift for fish chronically exposed to 100 or 300 mg·L-1
sediment suggests that these sediment strengths (and 1000 mg·L-1)
decreased the fishes' reactive distance (ability to detect surface
prey). The relatively slower reponse to surface drift for naive
grayling held only briefly in these sediment strengths prior to
testing may indicate that those fish subjected to prolonged sediment
exposure have improved their ability to discern surface food in turbid
water. Alternatively, short-term exposure to these sediment strengths
may have disrupted feeding activities to some extent. The similarly
rapid feeding response times for naive controls versus long-term
controls shows that the feeding activity of naive fish was not
disrupted by transfer of fish from the stock tank to the test
apparatus.
l
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-25 -
Unlike the findings with surface drift, suspended sediment
strengths of 100 or 300 mg·L-1 did not impair feeding response times
for grayling offered sub-surface drift (Artemia salina) or benthic
invertebrates ( tubificids). The ability of naive or chronically-
exposed grayling to detect and consume tubifex worms or brine shrimp
ih these sediment strengths equally as well as control fish was likely
due at least in part to the experimental design for this test. The
white background provided by the submersed nylon-mesh baskets may have
silhouetted these prey, making their· detection easier. Additionally,
holding fish within the confines or·-"each basket may have decreased the
distance between predator and prey sufficiently for these fish to
readily detect (and consume) these organisms at these sedime~t
strengths. Or perhaps the reactive distance for these sub-surface
food organisms at each respective suspended sediment strength, whether
related to visual or olfactory cues, is greater than that for surface
drift.
Several investigators have reported a reduction in the feeding
responses of salmonid fish due to the presence of suspended sediment.
Noggle (1978) found that a suspended sediment strength of 100 mg·L-1
reduced feeding of coho salmon smolts toward caddis fly larvae by 45%,
. and that feeding ceased altogether above 300 mg·L-1. Although both
juvenile cutthroat trout (Salmo clarki) and chinook salmon
(Oncorhynchus tshawytscha) can continue to feed on surface drift in
suspended sediment concentrations greater than 500 mg·L-1 (Griffin
1938), one study (Anon. 1965) reported that cutthroat trout subjected
for two hours to 35 mg·L -1 suspended sediment within a river sought
cover and stopped feeding. Berg ( 1982) determined that suspended
sediment with a turbidity of 60 NTU had a marked effect on the visual
ability of juvenile coho salmon. Delayed response times to surface
drift, mis-strikes at food, and frequent collisions of fish with an
obstacle within the test tank were evident. These findings are con-
sistent with those for Arctic grayling (particularly naive fish)
offered surface food in the presence of sediment suspensions >1 00
mg·L-1.
FISH CONDITION
With the exception of fish colour, all grayling reared for 6
weeks in placer mining sediment suspensions < 1000 mg·L-1 were normal
in appearance, showing no overt pathologies attributable to sediment
exposure. The observation that fish exposed to 300 and 1000 mg·L-1
were paler in colour is consistent with other findings for salmonid
fish exposed to elevated suspended sediment levels under field . or
laboratory conditions (Herbert and Merkens 1961, Herbert et al. 1961),
and probably reflects a contraction of epithelial chromatophores in
response to background colour.
Mean condition factors determined for groups of fish held for 3
or 6 weeks in control streams or those containing differing strengths
of suspended placer mining sediment were typical of those values found
.l.LA~KA RESOURCES LYHRAO
ti.J. DEPT. OF IXTEr:;oR
-26 -
for underyearling Arctic grayling captured from clearwater Yukon
streams (Birtwell et al. 1984). As in the present study, Sigler
(1981) found no change in condition factors for underyearling
steelhead trout or coho salmon held for extended periods in laboratory
streams containing sediment suspensions, whereas these fish grew less
than the control fish in clear water. Fish were provided an excess
food ration in both studies. Webb and Brett ( 1972, 1973) reported a
similar growth impairment (without change in condition factors) for
underyearling sockeye salmon (Oncorhynchus nerka) exposed to sublethal
concentrations of kraft pulpmill effluent or pentachlorophenol,
together with a reduced food conversion efficiency. As .in the current
investigation, the percentage moisture content of these contaminant-
exposed salmon was unchanged. A reduction in food conversion
efficiency could be caused by increasing maintenance energy costs,
thus reducing the proportion of energy available for growth (Warren
and Davis 1967);. ie. reducing the "scope for growth" (Brett 1976).
The reduced growth of grayling or other salmonid fish species caused
by suspended sediment may also reflect a decreased food intake, al-
though it is thought that this would be reflected in a reduction in
fish condition factor. As with other increased metabolic demands, a
sustained increase in swimming activity of fish due to suspended
sediment (Berg 1982). would increase energy costs, resulting in less
energy available for growth.
Since blood hematocrit values for salmonid fish generally
increase due to hypoxia (caused by impaired ga·s exchange or oxygen-
deficient waters) (Holeton and Randall 1967; Soivio et al. 1974 a,b),
the absence of any change in hematocrit for grayling exposed to sus-
pended sediment for 6 weeks suggests that these exposures did not
lower blood oxygen tension. O'Connor et al. (1977) reported elevated
hematocrits, red blood cell counts and hemoglobin values together with
·histological evidence of gill damage for certain species of estuarine
fish exposed to suspended sediment, whereas for other species these
blood values and gill histology were unchanged from controls.
Hematocrit values and gill histology of underyearling Arctic grayling
were shown previously to be unaffected by acute ( ~ 4 days) exposure
to suspensions of placer mining sediment under field or laboratory
conditions (McLeay et al. 1983). A lack of change in hematocrit
values does not necessarily imply no gill tissue damage, however,
since fish have a large "reserve" surface area of gill tissue
available for maintaining blood gas tensions at normal values (Randall
1970).
Exposure of Arctic grayling and other fish species to suspended
sediment at strengths which can be found within natural streams has
been shown to cause a number of typical stress responses, including
short-term increases in plasma cortisol levels (Redding and Schreck
1980), depletion of liver glycogen energy reserves (Sherk et al. 1974,
O'Connor et al. 1977), elevation of plasma glucose levels (Noggle
1978, McLeay et al. 1983) and depression of leucocrit values (McLeay
et al. 1983). When the stress is prolonged, certain fish stress
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-27 -
indices including plasma cortisol and glucose levels and numbers of
circulating white blood cells ( leucocrit) recover to basal or near-
basal levels ( McLeay and Brown 197 4, McLeay 1977, McLeay and Gordon
1977, Redding and Schreck 1980). These recoveries typify the stage of
resistance to stress (Selye 1950), and are only achieved at a
metabolic cost. Thus the apparent absence of change in leucocrit or
plasma glucose values for Arctic grayling following 6 weeks' exposure
to suspensions of placer mining sediment is not unexpected, and does
not imply that these fish were not stressed. A better understanding
as to whether or not the grayling · in this study were chronically
stre.ssed by suspended sediment, and the stage of this response after 6
weeks' exposure ( ie. resistance or exhaustion stages; Selye 1950),
would require a more detailed biochemical/histopathological
examination of test fish. This was beyond the scope of th~ present
investigation.
FISH PERFORMANCE
An examination of the performance of fish during or subsequent to
their exposure to environmental stressors can provide meaningful in-
formation concerning their condition and adaptive capabilities
(Wedemeyer and McLeay 1981; Wedemeyer et al. 1983). The present
sealed jar· bioassays, temperature tolerance tests and challenge tests
with the reference toxicant pentachlorophenol enabled a better under-
standing of the sublethal effects caused by prolonged exposure of
Arctic grayling to suspensions of placer mining sediment.
Results from the bioassays with pentachlorophenol showed that
grayling exposed for 6 weeks to 300 or 1000 mg·L-1 suspended sediment
were less able to withstand this reference toxicant than control fish
or those held in 100 mg·L-1 sediment. Similarly, both groups of fish
exposed to these higher sediment strengths for 6 weeks showed shorter
times to death (increased oxygen uptake rates) in sealed jar
bioassays. These results suggest that the adaptive capabilities of
grayling were diminished by prolonged exposure to suspensions of
placer mining sediment ~300 mg·L-1.
The increased oxygen uptake rate found for grayling held for 6
weeks in 100 or 300 mg·L-1 suspended sediment may reflect an increased
basal metabolic rate or a sustained increase in physical activity for
these fish. This response indicates a decreased scope for activity of
the fish (Fry 1971). Measurements of scope for activity have been
used previously to assess the impact of environmental stressors on
fish (Brett 1958; Wedemeyer and McLeay 1981). Since the ability of
grayling to withstand hypoxia was unaffected by chronic exposure to
any sediment strength examined (residual dissolved oxygen values were
unchanged), the decreased times to death found in sealed jar tests for
fish exposed to 300 or 1000 mg·L-1 sediment probably reflect
heightened ~nergy demands for these fish rather than impaired blood
gas exhange (D.J. Randall, pers. commun.). This conclusion is also
consistent with the lack of change in hematocrit values for the
sediment-exposed fish.
-28 -
Findings for the current temperature tolerance tests indicate
that the capacity of all fish groups to withstand high· temperatures
was unaffected by prolonged exposure to any strength of suspended
sediment examined. This result is consistent with previous evidence
that little if any change in the upper lethal temperature tolerance of
salmonid fish is caused by aquatic contaminants which do not block
oxygen exchange at the gills or otherwise impair tissue respiration
(McLeay and Gordon 1980; McLeay et al. 1983). The reduced temperature
tolerance found for one group of control fish (stream 8) simply
reflects the slightly lower temperature to which this group of fish
was acclimated (Brett 1952; Black 1953; McLeay et al. 1983).
GENERAL
Inasmuch as the sublethal effects of prolonged exposure of
salmonid fish to suspended sediment have previously received little
attention, the harmful effects caused by such exposures are not
clearly understood. The present study indicates that, at least for
the sediment type examined, direct fish mortalities are unlikely from
exposure to suspended sediment strengths less than or equal to 1000
mg·L-1 under otherwise optimal environmental conditions. However,
sublethal effects including a continued impairment of feeding
activity, impaired growth, decreased scope for activity and decreased
resistance to other environmental stressors can occur.
Present findings indicate that strengths of suspended placer
mining sediment as low as 100 mg·L-1 can affect fish growth and
feeding responses, and that strengths of 300 mg·L-1 or higher can
increase oxygen consumption (metabolic rate), lower the tolerance of
grayling to a reference toxicant, and cause fish to be distributed
further downstream. These findings provide cause for concern if
sediment concentrations above 100 ing·L-1 remain suspended in streams
inhabited by juvenile Arctic grayling or other sensitive fish species
for extended periods. Suspended sediment strengths as low as 100
mg·L-1 may also prove harmful to the long-term well-being of grayling
in natural stream environments. Although the effects on growth and
feeding response times for fish exposed to 100 mg·L-1 sediment for 6
weeks were minimal, the absence of a continuous supply of excess food
in the natural environment together with the greater effort required
for the detection and capture of available food, predator/prey inter-
actions and simultaneous exposure to other less-than-optimal environ-
mental conditions may increase the impact of prolonged exposure to
this suspended sediment strength.
The displacement of salmonid fish from upstream waters shown in
this study for suspended sediment strengths greater than 100 mg·L-1
and in a previous (Sigler 1981) laboratory investigation where stream
turbidity was 40 -50 NTU is of particular concern, as these findings
indicate that short~term pulses of suspended sediment may cause
downstream migration of otherwise resident fish. This downstream
displacement and probable reduction in the amount and quality of
living
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-29 -
space are cause for concern. Clarification of the effects of
suspended sediment on fish displacement and avoidance/preference
responses under natural and controlled environmental conditions is
desirable. A better understanding of the influence of sediment type
(particle shape and size) and concentration on fish behaviour, stress
responses and energetics should also be achieved.
ACKNOWLEDGEMENTS
We wish to acknowledge the co-operation of the ·placer miners
along Highet Creek, Yukon. The provision of placer mining sediment
and logistics support by Mr. S. Howe and Ms. M. Jack (Department of
Indian and Northern Development), fish by Messrs. R. Elvidge, B.
Anderson and A. VonFinster (Fisheries and Oceans Canada), .and fruit
flies by the Department of Zoology, University of B. C. is gratefully
acknowledged. We wish to thank Messrs. J. Kong and H. Wong for their
daily effort, dedication and input during all aspects of these
laboratory bioassays. Our thanks are also expressed to the
Environment Canada/Fisheries & Oceans laboratory staff at West
Vancouver for their analytical services, and to B.C. Research
(Vancouver) for. the use of their fish rearing/test facilities and for
sediment preparation and analysis. Drs. D.J. Randall (Department of
Zoology, University of B.C.) and J.G. Malick (Norecol Environmental
Consultants Ltd.) kindly provided assistance with data interpretation.
The technical assistance of Ms. S. Jones (drafting) and Ms. D. Henn
(typing) is also acknowledged with thanks.
-30 -
REFERENCES
Alderdice, D.F,. 1963. Some effects of simulataneous variation in
salinity, temperature and dissolved oxygen on the resistance of
juvenile coho salmon (Oncorhynchus kisutch) to a toxic substance.
Ph.D. Thesis. Univ. of Toronto~ 177 pp.
Anon. 1965. Water quality criteria for European freshwater fish.
Report on finely divided solids and inland fisheries. European
Inland Fisheries Advisory Committee. Int. J. Air Wat. Poll. 9:
151-168.
Anon. 1972. Testing Sieves and Their Uses. Handbook 53. W.S. Tyler
Inc. Mentor, Ohio. 48 pp.
Anon. 1979. Environmental Laboratory Manual. Environment Canada and
Fisheries & Oceans Canada. West Vancouver.
Anon. 1980. Standard Methods for the Examination of Water and
Wastewater. 15th edition. American Public Health Association,
American Water Works Association and Water Pollution Control
Federation. Washington, D.C. 1134 pp.
Anon. 1983. A Rationale for the Suspended Solids Standards for Yukon
Streams Subject to Placer Mining. Paper prepared by Fisheries &
Oceans and Environment Canada. February 1983. New Westminster,
B. C. 24 pp.
Berg, L. 1982. The effect of exposure to short-term pulses of suspended
sediment on the behavior of juvenile salmon ids. pp. 177-196. In
Proceedings of the Carnation Creek Workshop: A Ten-Year Review.
G.F. Hartman, ed. February 24-26, 1982.
Birtwell, I.K., G. Hartman, B. Anderson, D.J. McLeay and J.G. Malick.
1984. A brief investigation of Arctic grayling (Thymallus
arcticus) and aquatic invertebrates in the Minto Creek drainage,
Mayo, Yukon Territory. Can. Tech. Rep. Fish. Aquat. Sci. (In
Pre.).
Black, E.C. 1953. Upper lethal temperatures of some British Columbia
freshwater fishes. J. Fish. Res. Bard Can. 10: 196-210.
Brett, J .R. 1952.
Oncorhynchus.
Temperature tolerance in young Pacific salmon, genus
J. Fish. Res. Board Can. 9: 265-323.
Brett, J.R. 1958. Implications and assessments of environmental
stress. pp.· 69=83. In The Investigations of Fish-Power Problems
(P.A. Larkin, ed.). MacMillan Lectures in Fisheries, Univ. of B.C.
Vancouver.
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[
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[
[
["
L
[
[
b
[
r~
l:::l
[
L
r~
L
-31 -
Brett, J.R. 1971. Energetic responses of salmon to temperature. A
study of some thermal relations in the physiology and freshwater
ecology of sockeye salmon (Oncorhynchus nerka). Am. Zool. 11: 99-
113.
Brett, J.R. 1976. Scope for metabolism and growth of sockeye salmon,
Oncorhynchus nerka, and some related energetics. J. Fish Res.
Board Can. 33: 307-313.
Brett, J.R., J.E. Shelbourn and C.T. Shoop. 1969. Growth rate and body
composition of fingerling sockeye salmon, Oncorhynchus nerka, in
relation to temperature and ration size. J. Fish. Res. Board Can.
26: 2363-2394.
Campbell, H.J. 1954. The effect of siltation from gold dredging on the
survival of rainbow trout and eyed eggs in Powder River, Oregon.
Oregon State Game Comm. Report. 3 pp.
Carlander, K.D. 1969. Handbook of Freshwater Fishery Biology. Iowa
State Univ. Press, Ames. 75 pp.
Crouse, M.R., C.A. Callahan, K.W. Malueg, and S.E. Dominguez. 1981.
Effects of fine sediments on growth of juvenile coho salmon in
laboratory streams. Trans Amer. Fish. Soc. 110: 281-286.
Davis, J.C. 1975. Minimal dissolved oxygen requirements of aquatic life
with emphasis on Canadian species. A review. J. Fish. Res. Board
Can. 32: 2295-2332.
Davis, J.C. and R.A.W. Hoos. 1975. Use of sodium pentachlorophenate
and dehydroabietic acid as reference toxicants for salmonid
bioassays. J. Fish. Res. Board Can. 32: 41-416.
Ennis, G.L., A. Cinader, S. Mcindoe and T. Munsen. 1982. An annotated
bibliography and information summary on the fisheries resources of
the Yukon River Basin in Canada. Can. Ms. Rep. Fish. Aquat. SoL
1657. 278pp.
Gordon, M.R. and D.J. McLeay. 1977. Sealed-jar bioassays for pulpmill
effluent toxicity: effects of fish species and temperature. J.
Fish. Res. Board Can. 34: 1389-1396.
Gradall, K.S. and W.A. Swenson.
creek chubs to turbidity.
395.
1982. Responses of brook trout and
Trans. Amer. Fish. Soc. 111: 392-
Griffin, L.E. 1938. Experiments on the tolerance of young trout and
salmon for suspended sediment in water. Bull. Ore. Dept. Geol.
10: 28-31.
Herbert, D.W.M. and J.M. Richards. 1963. The growth and survival of
-32 -
fish in some suspensions of solids of industrial origin. Int. J.
Air Wat. Poll. 7: 297-302.
Herbert, D.W.M. and J.C. Merkens. 1961. The effect of suspended
mineral solids on the survival of trout. Int. J. Air WWat. Poll.
5: 46-55.
Herbert, D.W.M., J.S. Alabaster, M.C. Dart and R. Lloyd. 1961. The
effect of china-clay wastes on trout streams. Int. J. Air Wat.
Poll. 5: 56-75.
Holeton, G.F. and D.J. Randall. 1967. The effect of hypoxia upon the
partial pressure of gases in the blood and water afferent and
efferent to the gills of rainbow trout. J. Exp. Biol. 46: 317-
327.
Leitritz, E. and R.C. Lewis. 1976. Trout and Salmon Culture: Hatchery
Methods. Calif. Dep. Fish & Game. Fish Bull. 164.
Litchfield, J.T. 1949.
cent effect curves.
A method for rapid graphic solution of time-per
J. Pharmacol. Exp. Therap. 97: 399-408.
McLeay, D.J. 1976. A rapid method for measuring the acute toxicity of
pulpmill effluent and other toxicants to salmonid fish at ambient
room temperature. J. Fish. Res. Board Can. 33: 1301-1311.
McLeay, D.J. 1977. Development of a blood sugar bioassay for rapidly
measuring stressful levels of pulpmill effluent to salmonid fish.
J. Fish. Res. Board Can. 23: 2164-2175.
McLeay, D.J. and D.A. Brown. 1974. Growth stimulation and biochemical
changes in juvenile coho salmon (Oncorhynchus kisutch) exposed to
bleached kraft pulpmill effluent for 200 days. J. Fish. Res.
Board Can. 31: 1043-1049.
McLeay, D.J. and M.R. Gordon.
technique for measuring
stressful concentrations
Can. 34: 2164-2175.
1977. Leucocrit: a simple hematological
acute stress in salmonid fish, including
of pulpmill effluent. J. Fish. Res. Board
McLeay, D.J. and M.R. Gordon. 1980. Short-term sublethal toxicity
tests to assess safe levels of environmental contaminants. B. C.
Research Proj. Report No. 1-11-199. Prepared for Environment
Canada. Vancouver. 24 pp.
McLeay, D.J. and T.E. Howard. 1977. Comparison of rapid bioassay
procedures for measuring toxic effects of bleached kraft mill
effluent to fish. pp. 141-155. In Proc. 3rd Aquat. Tox. Workshop,
Halifax, N.S. Nov. 2-3, 1976. Envir. Prot. Serv. Tech. Rep. No.
EPS-5-AR-77-1. Halifax.
l
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l
[
l
[
I
L
[
'-
[
[
r
L
[
c
[
[
r
L
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McLeay, D.J., A.J. Knox, J.G. Malick, I.K. Birtwell, G. Hartman, and
G.L. Ennis. 1983. Effects on Arctic grayling (Thymallus arcticus)
of short-term exposure to Yukon placer m1n1ng sediments:
laboratory and field studies. Can. Tech. Rep. Fish. Aquatic
Sci. 1171. 134 pp.
Mathers, J .s., N.O. West, and B. Burns. 1981. Aquatic and wildlife
resources of seven Yukon streams subject to placer mining.
Government of Canada, Departments of Fisheries and· Oceans, Indian
and Northern Affairs, and Environment. 183 pp.
Noggle, C.C. 1978. Behavior, physiological and lethal effects of
suspended sediment on juvenile salmonids. M.S. Thesis. Univ.
Washington 87 pp.
O'Brien, W.J., C. Buchanan and J.F. Haney. 1979. Arctic zooplankton
community structure: exceptions to some general rules. Arctic 32:
237-247.
O'Connor, J.M., D.A. Neumann and J.A. Sherk, Jr. 1977.
effects of suspended sediments on estuarine fish.
Solomons Nat. Res. Inst. Publ. No. CERC-TP-77-3.
Sublethal
Maryland Univ.
92 pp.
Randall, D.J. 1970. Gas exchange in fish. pp. 253-292. In Fish
Physiology. Vol. IV. W.S. Hoar and D.J. Randall, eds. Academic
Press, N.Y.
Redding, J.M. and C.B. Schreck. 1980. Chronic turbidity and stress in
juvenile coho salmon and steelhead trout. Pac. N. W. For. Lab.
Report PNW-1705-16. Final report. June 13, 1980. 84 pp.
Corvallis, Oregon.
Schmidt, D. and W.J. O'Brien. 1982. Planktivorous feeding ecology of
Arctic grayling ( Thymallus arcticus). Can. J. Fish. Aquatic Sci.
39: 475-482.
Selye, H. 1950. Stress. Acta Inc., Montreal. 822 pp.
Sherk, J.A., J.M. O'Connor, D.A. Neumann, R.D. Prince and K.V. Wood.
1974. Effects of suspended and deposited sediments on estuarine
organisms -Phase II. Final report. 299 pp. Nat. Res. Inst.,
Univ. Maryland.
Sigler, J.W. 1981. Effects of chronic turbidity on feeding, growth and
social behavior of steelhead trout and coho salmon. Ph.D. Thesis.
Univ. Idaho. 169 pp.
Soivio, A., K. Westman and K. Nyholm. 1974a. Changes in haematocrit
values in blood samples treated with and without oxygen: a
comparative study with four salmonid species. J. Fish Biol. 6:
763-769.
-34 -
Soivio, A., K. Westman and K. Nyholm. 1974b. The influence of changes
in oxygen tension on the haematocrit value of blood samples from
asphyxic rainbow trout (Salmo gairdneri). Aquaculture 3: 395-401.
Sprague, J.B. 1973. The ABC's of pollutant bioassay using fish. pp. 6-
30. In Biological Methods for the Measurement of Water Quality.
ASTM STP 528. American Society for Testing Materials.
Philadelphia, PA.
Warren, C.E. and G.E. Davis. 1967. Laboratory studies on the feeding
bioenergetics and growth of fish. pp. 175-214. In S.D. Gerking
(ed.) The Biological Basis for Freshwater Fish Populations.
Blackwell Scientific Publications, Oxford.
Webb, P.W. and J.R. Brett. 1972. The effects of sublethal
concentrations of whole bleached kraftmill effluent on the growth
and food conversion efficiency of underyearling sockeye salmon
(Oncorhynchus nerka). J. Fish. Res. Board Can. 29: 1555-
1563.
Webb, P.W. and J.R. Brett. 1973. Effects of sublethal concentrations
of sodium pentachlorophenate on growth rate, food conversion
efficiency, and swimming performance in underyearling sockeye
salmon (Oncorhynchus nerka). J. Fish. Res. Board Can. 30: 499-
507.
Wedemeyer, G.A. and D.J. McLeay. 1981. Methods for determining the
tolerance of fishes to environmental stressors. pp. 247-275. In
Stress and Fish. A.D. Pickering, ed. Academic Press. London.
Wedemeyer, G.A., D.J. McLeay and C.P. Goodyear. 1983. Assessing the
tolerance of fish and fish populations to environmental stress: the
problems and methods of monitoring. In Advances in Environmental
Science and Technology. Wiley and Sons, Toronto. In press.
Zar, J.H. 1974. Biostatistical Analysis. Prentice-Hall Inc.,
Englewood Cliffs, N.J.
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TABLE 1.Particle size distribution for test sediment collected from a placer mine settling pond.
Untreated sedimenta
Sieve
size
(mesh)
Particle
size
(um)
Weight
(%)
Cumulative
weight (%)
Prepared
Sample no.1
Weight Cumulative
(%)weight (%)
sedimentb
Sample
Weight
(%)
no.2
Cumulative
weight (%)
+35 >400 0.0 0.0 0.0 0.0 0.0 0.0
+48 >300 0.0 0.0 0.0 0.0 0.0 0.0
w
+65 >210 0.1 0.1 0.0 0.0 0.0 0.0
U'1
+100 >150 0.4 0.5 0.0 0.0 0.1 0.1
+150 >100 3.3 3.8 0.2 0.2 0.1 0.2
+200 >75 17.1 20.9 2.3 2.5 1.6 1 .8
+325 >45 40.6 61.5 16.8 19.3 16.5 18.3
+400 >38 15.7 77.2 10.0 29.3 11.9 30.2
-400 <38 22.8 100.0 70.7 100.0 69.8 100.0
a Surficial sediment as collected from the downstream end of a de-watered settling pond.
bOven-dried (500 C)and pulverized (Vibratory ring pulverizer)for 2 min.
-36 -
TABLE 2.Oxygen uptake rate,volatile and fixed residue
for test sediment collected from a placer mine settling pond.
Characteristic
Sample
no.1
Sample
no.2
oxygen uptake rate at 150C 0.01 0.01
(mg °2·g-1 dry sediment·24h-1 )
oxygen uptake rate at 150C 0.01 0.01
(mg °2·ml -1 dry sediment·24h-1 )
volatile residue (%)5.4.
fixed residue (%)95.96 ..
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-37 -
TABLE 3.Metal contenta for test sediment collected from q
placer mine settling pond.
Concentration (ug'g-1 dry weight)
Component Sample no.1 sample no.2
arsenic As 653.649.
barium Ba 341.344.
beryllium Be 0.6 0.6
cadmium Cd 0.3 0.3
cobalt Co 12.2 12.0
chromium Cr 56.1 41.8
copper Cu 39.4 37.5
manganese Mn 705.705.
molybdenum Mo 4.6 2.3
nickel Ni 25.25.
phosphorous P 720.726.
lead Pb 13.11 •
tin Sn 2.0 2.0
strontium Sr 36.4 36.6
titanium Ti 649.632.
vanadium V 45.44.
zinc Zn 81.6 82.0
aluminum Al 20700.20800.
iron Fe 40300.40100.
silicon Si 4400.5160.
calcium Ca 3770.3710.
magnesium Mg 5510.5540.
sodium Na 420.390.
aBased on analysis of sediment digest by inductively coupled argon
plasma spectrograph (Anon.1979).
-38 -
TABLE 4.Effect of stream position on suspended sediment strength.
Nominal
sediment
strength Stream Stream position _._._----
(mg·L-1)no.Upstream Midstream Downstream
0 4 <Sa <Sa <Sa
0 8 <S <5 <5
100 2 95 97 91
100 5 111 98 110
300 3 308 305 316
300 6 318 308 310
1000 1 1030 1020 1030
1000 7 997 1010 1000
aNonfiltrable residue values determined for grab samples collected
concurrently at mid-depth.
r-'
l~
[
[
[
C
L
[
L
,-
L
I'
L
r:rr-JI r---,
L.
TABLE 6.Weekly mortalities of underyearling Arctic graylinga in test streams during prolonged exposure to
dHfering strengths of placer mining sediment.
Duration
of exposure
(weeks)
_______________-'-N,o~m=in:.::;a=.;l"___'s;;...;t=r~ngth of su spended
o (control)100
Stream 4 St:"::r:'<"e-am---=8c-Stream 2 Stream 5
Mb DC M D M D M D
sediment (mg.L-1)
300
Stream 3.Stream 6
M D M D
1000
Stream 1 Stream 7
M D M D
Od 0 0 0
0 0 0
0 0 0 0
0 0 0 0 0
0
0 0 a 2 0 3 0 0 0 0 0
2 0 3 0 5 0 0 0 0 2 2 0 2 0
3 e 0 0 0 0 0 0 0 0 0 0 0 0 0
4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
5 0 0 0 0 0 0 0 0 0 0 0 2 0 +:>
0
6 0 0 0 0 0 0 0 0 2 0 0 0 0 0
totalf 5 8 3 5 3 6 7 3
a Sixty fish added initially to each of eight test streams.
b Fish missing;presumed dead.
c Fish dead;examined for lesions.
d During the initial 7-day period for acclimation of fish to test streams.
e Ten fish removed from each stream for pentachlorophenol bioassays.
f Combined value for missing and/or dead fish in each stream throughout the test period.
,~
rm r----"1lJ (
TABLE 7.Weekly weights for groupsa of underyearling Arctic grayling exposed for 6 weeks to differing strengths
of suspended placer mining sediment.
Duration Nominal strength of suspended sediment (mg·L-1)
of exposure o (control)100 300 1000
(weeks)Steam 4 Stream 8 Stream 2 Stream 5 Stream 3 Stream 6 Stream 1 Stream 1
Ob 0.41 d 0.41 0.40 0.42 0.41 0.42 0.44 0.40
(0.09)(0.08)(0.08)(0.09)(0.08)(0.09)(0.09)(0.09)
oc 0.55 0.53 0.53 0.54 0.52 0.52 0.53 0.56
(0.12)(0.11)(0.11)(0.10)(0.10)(0.11)(0.11) (0.10)
0.64 0.64 0.62 0.61 0.62 0.63 0.59 0.66
(0.18)(0.15)(0.15)(0.15)(0.14)(0.15) (0.14)(0.14)
2 0.80 0.11 0.15 0.80 0.14 0.11 0.68 0.15
(0.25)(0.18)(0.18)(0.18)(0.18)(0.11)(0.18)(0.17)
3 0.91 0.96 0.86 0.94 0.85 0.91 0.14 0.83 ~......
(0.31)(0.24)(0.22)(0.23)(0.22)(0.20)(0.19) (0.19)
4 1.11 1.13 0.98 1.10 0.99 1.08 0.84 0.96
(0.36)(0.30)(0.24-)(0.28)(0.21 )(0.26)(0.21)(0.20)
5 1.28 1.31 1.13 1.22 1.13 1.24 0.94 1.05
(0.42)(0.35)(0.29 )(0.35)(0.36)(0.32)(0.20) (0.24)
6 1.40 1.39 1.30 1.38 1.30 1.33 1.01 1.18
(0.49)(0.41)(0.37)(0.45)(0.44)(0.35)(0.25)(0.28)
a Sixty fish added initially to each of eight test streams.
b Upon addition of fish to test streams.
c Following a 1-day period for acclimation of fish to test streams.
d Mean weigh1~(g),with standard deviation in parenthesis.
TABLE 8.PercEmtage distribution of underyearling Arctic grayling in four equal portions of each test stream following
exposure of fish to suspended placer mining sediment for 4 or 5 weeks.
Duration of Stream Nominal strength of suspended sediment (mg·L-1)
exposure position o (control)100 300 1000
(weeks)(quarter)Stream 4 Stream 8 Stream 2 Stream 5 Stream 3 Stream 6 Stream 1 Stream 7
4 1 11 a 48 6 6 2 2 0 2
2 37 38 40 7 10 13 15 10
3 15 12 27 40 53 40 15 48
4 37 2 27 47 35 45 70 40
5 1 0 7 12 2 2 7 2 4
2 59 38 34 18 4 18 14 15
3 37 55 28 11 55 32 36 49
4 4 0 26 69 43 48 ~39 32 N
4 +5 1 6 27 9 4 2 4 1 3
(mean)2 48 38 37 13 7 16 15 13
3 26 34 27 26 54 36 26 48
4 20 1 27 57 37 44 58 36
4 +5 1 +2b 54 66 46 17 9 20 16 16
(mean)3 +4C 46 34 54 83 91 80 84 84
apercentage of fish occupying stream position indicated.
bUpstream half of test stream.
cDownstream half of test stream.
_I ..t Iir,r--:,..,J
,...--...
,"j IJ ,-------,
l J
TABLE 9.Effect of differing strengths of suspended placer m~n~ng sediment on the feeding response to
surface drift (Drosophila melanogaster)for underyearling Arctic grayling held in test streams for 5 weeks.
Feeding response time (seconds)C
Trial Replicate o (control)~~L-1 Sediment 300 mg.L-1 Sediment 1000 mg·L-1 Sediment
no.a no.b Stream 4 Stream 8 Stream 2 Stream 5 Stream 3 Stream 6 Stream 1 Stream 7
1 10 6 45 26 40 143 166 >360
2 5 7 5 40 80 60 40 115
3 7 7
21 25 30 47 150 46
4 7 6 17 34 17 87 198 140
5 7 5 10 19 17 75 48 296
mean 7 6 20 29 37 82 120 >191
(SO)2 1 15 8 26 37 72 (>131)
2 1 4 6 15 13 28 23 184 22
2 5 5 15 39 20 13 115 32
3 6 6 8 39 21 10 19 15
4 6 6 20 18 30 10 92 43
5 5 8 20 40 19 43 >360 23
6 9 5 20 21 45 20 >360 21 .j:::o
w7861553102632221
mean 6 6 16 32 38 26 >165 25
(SO)2 1 4 15 30 20 (>145)9
3 1 9 13 31 49 26 45 88 22
2 8 8 8 35 23 22 49 82
3 10 6 15 26 82 12 145 45
4 5 7 15 31 18 68 61 40
5 6 8 10 14 20 12 60 24
6 6 7 26 10 26 18 59 55
7 5 7 7 18 21 10 22 21
8 11 6 22 31 15 21 90 21
9 16 8 6 28 23 9 44 238
mean 8 8 16 27 28 24 69 61
(SO)4 2 9 12 20 20 35 69
a Each trial conducted with 3 fish selected randomly from the test stream.
b Test rep,eated using same 3 fish.
c Time for fish to consume a live fruit fly placed on stream surface 60 cm upstream from fish.
TABLE 10.Effect of d.iffering strengths of suspended placer mining sediment on the feeding response to
surfaee drift (Drosophila melanogaster)for underyearling Arctic grayling held in test streams for 1 hour
prior to testing.
Feeding response time (seconds)C
1000 mg.L-1 SedimentTrialReplicateo(control)100 mg.L-1 Sediment 300 mgoL-1 Sediment
no.a no.b Stream 4 Stream 8 Stream 2 Stream 5 Stream 3 Stream 6 Stream 1 Stream 7
1 19 7 >360 >360 >360 285 >360 45
2 6 11 13 24 >360 175 >360 209
3 4 19 74 11 >360 156 >360 288
4 26 9 72 21 50 54 >360 >360
5 4 6
14 14 >360 13 >360 160
mean 12 10 >107 >86 >298 137 >360 >213
(SD)10 5 145 153 139 107 0 121
-l:=>
2 1 21 85 >360 260 >360 320 >360 360 -l:=>
2 12 31 226 100 80 29 310 360
3 10 27 17 206 >360 187 >360 342
4 5 5 23 47 114 43 >360 360
5 6 6 10 16 18 37 >360 360
6 4 6 21 28 85 27 >360 360
7 12 12 21 20 69 14 >360 360
mean 10 25 >97 97 >155 94 >353 >357
(SD)6 29 140 98 143 116 19 7
a Ealch trial conducted with .3 fish selected randomly from the outside rearing tank.
b Test repeated using same 3 fish.
c Time for fish to consume a live fruit fly placed on stream surface 60 cm upstream from fish.
TABLE 11.Effect of differing strengths of suspended placer m~n~ng sediment on the feeding response
to sub-surface drift (Artemia salina)for underyearling Arctic grayling held in test streams for 6 weeks.
Total no.of brine shrimp consumed (n=10)CObservation._--'--:-_._
Trial time 0 (control)100 mg.L-1 Sedimen~300 mg.L-1 Sediment 1000 mg.L-1 Sediment
no.a (min)b Stream 4 Stream 8 Stream 2 Stream 5 Stream 3 Stream 6 Stream 1 Stream 7
2
3
1
3
5
10
15
30
45
60
1
3
5
10
15
30
45
60
1
3
5
10
15
30
45
60
Reponse time
(min)d
8
10
4
8
10
6
9
10
4
<3-5)
7
10
8
10
7
10
3
8
10
5
10
6
10
3
5
10
4
8
10
10
3
(1-5)
4
7
9
10
5
7
9
10
7
10
8
(3-10)
5
10
8
9
10
5
10
4
(3-5)
o
o
o
o
o
1
7
8
o
o
o
o
o
o
o
o
o
1
1
1
2
2
3
4
60
1
1
2
3
3
6
6
6
1
1
3
4
4
5
5
7
1
1
1
1
1
2
2
2
60
a Each trial conducted with 3 fish selected randomly from the test stream.
b Baskets raised at fixed time intervals in order to count no.of brine shrimp uneaten.
c Ten live brine shrimp placed in a nylon-mesh basket submersed in the test stream,and fish introduced at time O.
d Mean time to consumption of all brine shrimp (range in parentheses).
TABLE 12.Effect of differing strengths of suspended placer mining sediment on the feeding response to a benthic
invertebrate (tubificid worms)for underyearling Arctic grayling held in test streams for 5 weeks vs.1 hour prior
to testing.
Duration Total no.of worms consumed (n=10)CofObservation
sediment Trial time o (control)100 mg.L-1 Sediment 300 mg.L-1 Sediment 1000 mg.L-1 Sediment
exposure no.a (min)b Stream 4 Stream 8 Stream 2 Stream 5 Stream 3 Stream 6 Stream 1 Stream~
5 weeks 1 6 6 6 7 5 8 0 0
3 6 7 7 9 8 10 0 0
5 7 8 8 10 9 0 0
10 9 10 9 10 0 0
15 10 10 0 0
30 1 0
45 1 0
60 1 0
5 weeks 2 1 5 3 3 4 8 7 0 0
3 7 6 3 10 10 8 0 0
5 8 8 9 8 0 0
10 10 9 10 10 0 0
15 10 0 0
30 0 0
45 0 0
60 0 0
5 weeks 3 1 6 8 8 9 0 7 0 0
3 10 10 10 10 0 8 0 0
.r::-
5 4 10 0 0
0"1
10 9 0 0
15 10 0 0
30 1 0
45 1 0
60 1 0
Response time 9 9 9 4 9 6 >60 >60
(min)d (3-15)(3-15)(3-15 )(3-5)(3-15)(3-10)
hour 1 8 7 4 1 5 8 0 0
3 9 9
4 8 7 10 0 0
5 10 10 6 10 10 0 0
10 10 0 0
15 0 0
30 0 0
45 0 0
60 0 0
Response time 5 5 10 5 5 3 >60 >60
(min)d
a Each trial conducted with 3 fish selected randomly from the test stream/outside tank.
b Baskets raised at fixed time intervals in order to count no.of worms uneaten.
c Ten live tubifex worms placed in a nylon-mesh basket submersed in the test stream,and fish introduced at time O.
d Mean time to consumption of all worms (range in parentheses).
'~l-~J'-.~I
•j ~l.."
TABLE 13.Length,weight,and condition factor of underyearling Arctic grayling following exposure to differing
strengths of suspended placer mining sediment for 3 or 6 weeks.
Nominal
Duration of sediment Fish length Fish weight Condition factor
exposure strength Stream No.of (cm)(g)(K)
(weeks)(mg.L-1)no.fish Mean SD Mean SD Mean SD
3 0 4 10 4.8 0.5 0.99 0.28 0.86 0.07
0 8 10 4.8 0.6 1.01 0.34 0.86 0.11
100 2 10 4.8 0.3 0.93 0.23 0.83 0.05
100 5 10 4.9 0.4 1.13 0.29 0.96 0.07
300 3 10 4.9 0.2 1.00 0.20 0.85 0.07 .j::>
300 6 10 4.8 0.5 1.07 0.29 0.95 0.07 '-l
1000 1 10 4.6 0.4 0.82 0.22 0.82 0.05
1000 7 10 4.6 0.3 0.95 0.24 0.96 0.08
6 0 4 45 5.4 0.6 1.40 0.49 0.85 0.10
0 8 42 5.5 0.5 1.39 0.41 0.81 0.11
100 2 47 5.2 0.5 1.30 0.37 0.90 0.11
100 5 45 5.3 0.5 1.38 0.45 0.89 0.09
300 3 47 5.2 0.5 1.30 0.44 0.92 0.11
300 6 44 5.3 0.5 1.33 0.35 0.88 0.09
1000 1 43 4.9 0.4 1.01 0.25 0.83 0.11
1000 7 47 5.1 0.4 1.18 0.28 0.88 0.08
TABLE 14.Biological characteristics determined for underyearling Arctic graylinga following exposure to
different strengths of suspended placer mining sediment for 6 weeks.
Nominal strength of suspended sediment (mg.L-l)
Variable Statistic
o (control)
Stream 4 Stream 8
100
Stream 2 Stream 5
300
Stream 3 Stream 6
1000
Stream 1 Stream 7
length
(cm)
weight
(g)
condition
factor (K)
body
moisture (%")
hematocrit
(%)
leucocrit
(%)
plasma
~lucose (mg%)
mean
SD
mean
SD
mean
SD
mean
SD
mean
SD
mean
SD
mean
SD
5.1
0.6
1.18
0.41
0.84
0.08,
77
1
34
7
1.0
0.4
62
8
5.5
0.4
1.31
0.27
0.78
0.09
78
1
30
3
1.0
0.2
60
12
5.2
0.4
1.19
0.25
0.85
0.10
78
1
36
5
0.9
0.2
68
7
5.3
0.5
1.25
0.35
0.82
0.06
77
1
29
5
1.0
0.2
58
7
5.2
0.3
1.18
0.24
0.82
0.05
77
2
35
6
0.9
0.1
67
8
5.4
0.3
1.36
0.29
0.85
0.05
77
2
31
4
1.0
0.2
62
7
5.0
0.5
0.98
0.26
0.78
0.06
79
1
28
4
1.0
0.2
57
8
5.0
0.5
1.05
0.34
0.80
0.07
78
1
30
5
0.9
0.2
59
6
a Values determined for groups of 10 fish sampled randomly from each test stream.
-.-',
J
-,i'I:1
[-j
TABLE '15._Acute lethal tolerance of underyearling Arctic grayling to the reference
toxicant pentachlorophenol following ex~osure to differing strengths of suspended
placer mining sediment for 3 weeks.
aDetermined by exposing groups of 10 fish to 30-L volumes of pentachlorophenol dissolved in clear
(NFR <5 rngoL-1)freshwater.
bLethal time to 50%mortality of test fish.
C95%confidence interval.
·Pooled value for treatment differs significantly (P <0.05)from that for controls.
TABLE 16.Acute lethal tolerance of underyearling grayling to the reference toxicant
pentachlorophenol following exposure to differing strengths of suspended placer mining
sediment for 6 weeks.
Suspended
sediment Fish weight Time to death (min)in
strength Stream (.&L-_150 ug·L-1 pentachlorophenola
(mg.L-1)no.Mean 3D LT50 b 95%CIe
0 4 1.46 0.47 285 261-311
0 8 1.57 0.55 310 258-372
100 2 1.24 0.37 302 288-317 (J1
100 5 1.32 0.48 300 283-318 0
300 3 1.53 0.53 265*234-299
300 6 1.42 0.49 235*208-266
1000 1 0.91 0.22 260*226-299
1000 7 1•11 0.20 265'250-281
aDetlarmined by exposing groups of 10 fish to 30-L volumes of pentachlorophenol dissolved in clear
(NFR <5 mg.L-1)freshwater.
bLethal time to 50%mortality of test fish.
e95%confidence interval.
*Pooled value for treatment differs significantly (P <0.05)from that for controls.
l:,.r:-l ,-------,
J
TABLE 11.Response of underyearling Arctic grayling to hypoxiaa following exposure to differing strengths of
suspended placer mining sediment for 6 weeks.
Time to death
(min)
Suspended
sediment
strength
(mg·L-l)
Stream
no"
Fish weight
-(g)
Mean SD LT50 h 95%crc
Residual oxygen at
death (mg02·L-1)
Mean SD Range
0 4 1.28 0.30 141 134 -162 2.1 0.5 1.8 -3.2
0 8 1.11 0.21 158 140 -179 2.9 0.2 2.4 -3.2
<.J"1
145 134 -
.....100 2 1.29 0.31 157 2.7 0.3 2.2 -3.0
100 5 1.28 0.17 145 134 -157 2.4 0.3 2.0 -3.2
300 3 1.25 0.35 125·113 -139 3.1 0.5 2.3 -3.9
300 6 1.45 0.24 115·106 -124 2.9 0.8 2.1 -4.5
1000 1 1.15 0.20 125*112 -140 3.2 0.4 2.6 -3.6
1000 7 1.29 0.34 125·116 -135 2.6 0.4 2.2 -3.5
aDetermined by sealed jar bioassays (n =10 )with test suspensions at 20 oc.
bLethal time to 50%mortality of test fish.
C95%confidence interval.
·Pooled value for treatment differs significantly (P <0.05)from that for controls.
TABLE 18.UppElr lethal temperature tolerance of underyearling Arctic grayling following exposure
to differing strengths of suspended placer mining sediment for 6 weeks.
Suspended Acclimation temperaturea Temperature at death b
sediment Sample (oC)(°C)
strength Stream size
(mg·L-1 )no.(n)Mean SD Mean SD Range
0 4 15 15.2 0.4 27.7 0.3 26.9 -28.2
0 8 8 14.0 0.4 27.0 0.7 26.0 -27.7
100 2 17 15 •.1 0.3 27.7 0.3 26.8 -27.9 (Jl
N
100 5 15 15.6 0.4 27.9 0.3 27.2 -28 .•1
300 3 17 15.4 0.4 28.0 0.2 27.8 -28.2
300 6 14 15.1 0.4 27.7 0.1 27.5 -28.1
1000 1 9 14.9 0.4 27.7 0.1 27.6 -27.8
1000 7 17 14.9 0.6 27.8 0.2 27 .6 -28.0
aBased on dai.ly record of water temperature in each test stream.
bDetermined by increasing the temperature of each suspension at 10 C·h-1 until all fish were dead.
~r:..---f ~.'r-J r:-J r-J r:-J nTT r-}r:-:l r--:-J LTJ ~i-~.--,~I I I .j
I J I l"___,..__-3 I J J
-53 -
-54 -
Figure 1.Illustration of test streams showing reservoir barrels,
barrel stirrers,peristaltic pumps for dispensing
sedimen~suspensions,recycle pumps and air supply.
[
[
[
[
[
r
L
[
[
[
L.;tJ
[
[
l
Compressed
Air
Supply
r--:L ,j
Removable
Screen Partition
Screen
Partition
Emeroency
OxYoen
Peristaltic Pump --t»dJPP
(70 mi·min -I per strl8am
8
51;""~PP(l700rpm)~==~
g ~20·L Capacity
Reservoir Barrel
/0 em
,'"-:'
I ,
~~~~~'f---T:~~~~~~:-:if"'--- -r-
20cm
'+-I1------------2/0cm-------------
Four Pumps
Four Pumps
-56 -
Figure 2.Relationship of nonfiltrable residue (NFR)concentration
of placer mining sediment added to barrel vs.suspended
sediment strength within test streams.
[
[
C
[
[
[
[
r
L
r-
L
~-------_.-._--._---
5000
z 40000
~
Q:
to-
Z
Wu-3000z-
0'
u..J
..JCt
1TIWE-....J
Q:-
Q:2000
<tQ:
mLL
Z
..J
LEGEND<tLL
ZO *End of stream::IE 1000
0 o Middle of streamZ
0~--1.~-L_...1.-----JL..---L_-L-_.L---1_--L._~_.L----L_~_...L----IL.----'-_....I-_..L------I_""'"
o 100 200 300 400 ~oo 600 700 800 900 1000
NFR IN TEST STREAMS (mg·L -I)
-58 -
Figure 3.Illustration of daily fluctuations in concentration of
nonfiltrable residue within each test stream throughout
the 6-week exposure period.
r~
L
[
[
[
[
L
[
L,
L
r-
L
L
r-J,:-l,
Stream I
Stream 7
...._----.....
"''''----_/
Stream 6
Stream 3
--Stream 4
14
",
CONTROLS <5
21
Stream 8 ••- •-
28 35
,
42
Strtlam 5
Stream 2
EXPOSURE (days)
-60 -
Figure 4.Illustration of daily fluctuations in turbidity within
each test stream throughout the 6-week exposure period.
!
L
I
I
IL
!
L
[
[
[
[
C
C
[
[
(
L
I'
L
0'1......
42
Str~am I
.....Stream 7
352821
,",.....-.---..-----••---••:;';.;';.;-;.:':;.:.-::•.:.;-;-:.:.a...._,,;.'.:',;,'-'-"-.----"'----:,:-:;-:;-::;-:.:-.:.-_
CONTROLS <3
I
147
,,-...--..-------
2200
2000
1800
1600
;:)
t-1400 -'I.L-1200
>-t-
O 1000
ma::
:::>800
t-
600
400
200
0
EXPOSURE (days)
Figure 5.
-62 -
Effect of suspended placer mlnlng
(weekly wet weight gain)of
grayling.Mean values for each
together with the 95%confidence
only.
sediment on the growth
underyearling Arctic
treatment are shown,
intervals at 6 weeks
r
[
r
L
[
[
C
C
rc
[
[
r:
L
r~
L
L
65
LEGEND
Nominal strength of
suspended sediment
(mg·L-I)
o 0 (control)
•100
x 300
l:>.1000
1 2 3 4
DURATION OF EXPOSURE (weeks)
o
60 fish added to each
of 8 test streams
(120 fish per treatment)
sediment added
(after I week
ac~limation )
0.7
0.9
0.3
-63 -
0.6
0.2
0.4
0.5
0.8
0.1
0.0 I__L..--_....L..----L-----L--_-.--L-_--I.-_---J...--_
o
1.1
1.0
1.2
1.4
1.3
1.5
L
L
~
-
L
-
[
[
L
nL,
r -L Ot-
.-~-t-L :I:
(!)
W.~~-
6
C
C
[
A
L
r'L
I -
I -
~
[
-64 -
Figure 6.Illustration of effect of differing strengths of
suspended placer mining sediment on feeding response for
underyearling Arctic grayling held in test streams for
(a)5 weeks or (b)1 hour prior to testing.Bars
repr~sent mean values for separate trials,and broken ex~
tensions of bars represent "greater than"values.
['
[
[
[
[
r
l~
[:
[
c
[
[
r~
L
I'
L
L
SUSPENDED SEDIMENT STRENGTH (mg·L -I)
-65 -
7
I I
I •
I •
1000
6
'300100
(a)F ish exposed to sediment
for 5 weeks.
o (controls)
w 160
~
~
w 120
U>zog;80
w
0:::
(!)40z
ow~0 L..I&lltmzL__m['L_-.lklJU~.~L_
Stream no.4 8 2 5
_200
(.)
Q)
rn-
SUSPENDED SEDIMENT STRENGTH (mg·L -I)
7
1000'300
'3 6
100
2 5
(b)Naive fish
(exposed to sediment
for I hour).
o
Stream no.4 8
o (controls)
40
'360
(.)
Q)
~240
w
~
~200
w
U>
~160
0-
f3
0:::120
(!)z
ow 80w
LL
'320
280-
[
c
~
c
[
c
[
b
-66 '-
Figure 7.Illustration of effect of differing strengths of
suspended placer mlnlng sediment on time to consume
groups of 10 sub-surface drift organisms (Artemia salina)
for underyearlirig Arctic grayling held in test streams
for 6 weeks prior to testing.Bars r~present values
derived for each trial,and broken extensions of bars re-
present "greater than"values.
[
[
r
L
[
[
[
L
J-
L
r'
I~
L
7
!I
1000
1000
,,"I
300
300
5
-67 -
100
100
2
SUSPENDED SEDIMENT STRENGTH (mg·L -I )
8
(b)Naive fish
(exposed to sediment
for I hour).
o (c ontrols)
o (controls)
o
Stream no.
c:>z
o 10wwu..
60-c
E 50
---w
~40..-
wen 30z
0a..en 20w
0::
(9z 100wwu..
0
Stream no.4
60-(a)c Fish exposed to sediment
·5 for 5 weeks.......50
w
~
~40
wenz 300a..enw
0::20
I'
L
[
r~
L
[
[
[
[~
nLJ
[
[
b~
E
C
C
r..~13
[
L
SUSPENDED SEDIMENT STRENGTH (mg·L-I)
-68 -
Figure 8.Illustration of effect of differing strengths of
suspended placer mlnlng sediment on time to consume
groups of 10 benthic worms (tubificids)for underyearling
Arctic grayling held in test streams for (a)5 weeks or
(b)1 hour pdor to testing.Bars represent values de-
rived fqr each tri,H and broken extensions of bars repre-
sent "greater than"values..
[
r~
L
[
.
[
c
[
L
[
L
I
L
r
L
L
SUSPENDED SEDIMENT STRENGTH
-69 -
7
1000
6
(mg·L-I)
300
5
100
24 8
o(c antrals)
60
10
Streamna.------
50
-c:
E-
w 40~
I-
W
Cf)
Z
0
Cl.30Cf)
W
0:
(!)
Z
0
Ww 20I.L..
[
[
[
[
[
r:
r:
r~
r~
LJ
I'
L
-70 -
Figure 9.Effect of 3-week exposure of underyearling Arctic gray ...
ling to suspended placer mining sediment on their acute
lethal tplerance to the reference toxicant pentachloro-
phenol.Points represent lethal times to 50%mortality
of fish (LT50),bars represent 95%confidence intervals.
r
L
[
[
[
[
C
[
l
I 7
1000
3 6
300
-71 -
2 5
100
r
325r-
225
250
350
200 '----~---~----------------
Stream no.4 8
o(controls)
-c
E-300
:I:
~
W
0
0~
275
w
~-~
f'
L
Ie
L
SUSPENDED SEDIMENT STRENGTH (mg·L -I)
Figure 10.
-72 -
Effect.of prolonged (6-week)exposure of under.;.
yearling Arctic grayling to suspended placer mining
sediment on their acute lethal tolerance to the
reference toxicant pentachlorophenol.Points
represent lethal times to 50%mortality of fish
(LT50),bars represent 95%confidence intervals.
[
[
[
[
C
[
L
r'
L
f'
L
L
SUSPENDED SEDIMENT STRENGTH (mg·L -I)
I 7
1000
3 6
300
2 5
100
4 8
O(controls)
-73 -
110
120
170
160
180
100 L.-_
Stream no.
-150
c
E-
:I:
~140w
0
0
I-
W
::E 130
I-
r
L
[
[
[
[
[
[
[
[
I '
L
r
L
Figure 11.
-74 -
Effect of prolonged (6-week)exposure of unde~~
yearling Arctic grayling to suspended placer mining
s~diment on their residual dissolved oxygen values
at death in sealed jar bioassays.Points represent
mean values,bars represent 95%confidence
intervals.
r~L.
-
[
b
[
[
[
r'
L
f'
L
-75 -
SUSPENDED SEDIMENT STRENGTH (mg·L -I)
I 7
1000
3 6
300
2 5
100
4 8
o(controls)
3.6
3.4
3.2
2.0 L-_
Stream no.
-
I 3.0
.....J
Ct
E-
Z
IJJ 2.8(!)
)0-
X
0
0
IJJ>2.6.....J
0enen
0
.....J
<t:::>2.40
CJ)
IJJa::
2.2
r=
L
rI,
L2
r
L
L
[
L
[
[
[
[
1-'
L.;
Figure 12.
-76 -
Effect of p~olonged (6-week)exposure of under-
yearling Arctic grayling to suspenp-edplacer mining
sediment on their time to death in sealed jar
bioassays.Points represent lethal times to 50%
mortality of fish (LT50),bars represent 95%
confidence intervals.
r~
L
[
[
C
[
[
[
~-~
I'
L
r .
IL~
L
I 7
1000
3 6
300
-77 -
2 5
100
SUSPENDED SEDiMENT STRENGTH (mg·L-I)
350
325
250
375
225
-c
E-300
::I:
~
W
0
~
275
w
::E-~
20J-----------------------
Stream no.4 8
O(controls)
r
L
[
[
[
[
,
[
[
r'
['
[
E
C
[
E
[
[
Figure 13.
-78 -
Effect of prolonged (6-week)exposure of under-
yearling Arctic grayling to suspended placer mining
sediment on their upper lethal temperature
tolerance.Points represent mean temperatures at
death,bars represent 95%confidence intervals.
[
[
[
r~
I
r-'
L
r
L
[
[
[
L
'"L
r"
IL~
t
-----
28.5
I 7
1000
(mg·L-I)
3 6
300
-79 -
2 5
100
SUSPENDED SEDIMENT STRENGTH
4 8
o(controls)
26.0 1-------------------
Stream no.
28.0 ~~~-r ~u
0-
~27.5
IJ.J
0
~
IJ.Ja::27.0::::>
!ia::
IJ.J
Q.
~
IJ.J
I-
26.5
[
[
[
[
[
[
[
[
[
APPENDIX 1.Daily water quality characteristics in test streams during prolonged exposure of underyearling Arctic grayling to
differing strengths of suspended placer mining sediment.
Nominal
sediment Dissolved Nonfiltrable Inflow
strength Stream Temperature oxygen Conductance residue Turbidity rate
Date (mg.L-1)no.(OC)a (mg.L-1 )a pHa (umho.cm-1 )a (mg.L-1 )a (FTu)a (ml·min-1 )
14/07183 0 4 14.5 9.6 6.4 14 <5 1 _b
0 8 13.9 9.6 6.4 14 <5 1
0 2 14.4 9.5 6.4 14 <5 1
0 5 14.5 9.6 6.3 15 <5 1
0 3 14.4 9.6 6.l.1 14 <5 1
0 6 14.4 9.5 6.L1 14 <5 1
0 1 14.3 9.6 6.4 15 <5 1
0 7 14.4 9~6 6.4 14 <5 1
15/07183 0 4 14.4 9.5 6.3 15 <5 1 00
0 8 13.8 9.5 6.4 14 <5 1 0
0 2 14.3 9.5 6.3 15 <5 1
0 5 14.6 9.7 6.3 15 <5 1
0 3 14.5 9.5 6.2 15 <5 1
0 6 14.2 9.5 6.3 14 <5 1
0 1 14.3 9.5 6.3 14 <5 1
0 7 14.3 9.5 6.3 15 <5 1
16/07183 0 4 14.5 9.6 6.4 13 <5 1 270
0 8 13.8 9.8 6.3 13 <5 1 250
0 2 14.3 9.5 6.4 14 <5 590
0 5 14.8 9.5 6.3 13 <5 1 490
0 3 14.6 9.6 6.2 13 <5 1 430
0 6 14.4 9.6 6.5 13 <5 1 330
0 1 14.3 9.6 6.1 14 <5 1 700
0 7 14.4 9.8 6.3 13 <5 1 490
aSampled/determined mid-stream.
bNot determined.
r---,~,r---
~,J to ,J
APPENDIX 1 (cont'd.)
Nominal
sediment Dissolved Nonfiltrable Inflow
strength Stream Temperature oxygen Conductance residue Turbidity rate
Date (mg.L-1)no.(Oc)a (mg.L-1)a pHa (umho·cm-1 )a (mg·L-1)a (FTu)a (ml'min-1 )
17/07/83 0 4 13.2 9.7 6.2 13 <5 1 280
0 8 12.6 9.6 6.3 13 <5 1 270
0 2 13.2 9.8 6.1 13 <5 1 590
0 5 13.6 9.4 6.2 13 <5 1 500
0 3 13.4 9.7 6.3 14 <5 1 420
0 6 13.2 9.4 6.3 12 <5 1 340
0 1 13.3 9.8 6.2 13 <5 1 700
0 7 13.4 9.2 6.3 12 <5 1 490
18/07183 0 4 14.0 9.7 6.5 18 <5 1 260
0 8 13.4 9.7 6.6 18 <5 1 230 00
0 2 14.0 10.0 6.6 16 <5 1 550 .....
0 5 14.2 9.8 6.6 16 <5 1 455
0 3 14.2 10.0 6.5 17 <5 1 395
0 6 13.9 9.7 6.5 18 <5 1 305
0 1
14.0 10.1 6.6 18 <5 1 650
0 7 14.0 9.8 6.6 16 <5 1 465
19/07/83 0 4 14.4 10.1 6.8 17 <5 1 245
0 8 13.6 10.5 6.9 17 <5 1 230
0 2 14.6 10.0 6.8 15 <5 1 545
0 5 14.8 10.1 6.8 17 <5 1 455
0 3 14.7 10.0 6.9 16 <5 1 390
0 6 14.5 10.1 6.8 16 <5 1 305
0 1 14.7 9.9 6.8 17 <5 1 635
0 7 14.6 10.1 6.8 17 <5 1 460
aSampled/determined mid-stream.
APPENDIX 1 (cont.'d.)
Nomina.l
sediment Dissolved Nonfiltrable Inflow
strength Stream Temperature oxygen Conductance residue Turbidity rate
Date (mg.L-'I)no.(OC)a (mg.L-1)a pRa (umho·cm-1 )a (mg.L-1)a (FTU)a (ml·min-1 )
20107/83 0 4 14.6 10.1 6.6 14 <5 1 270
0 8
14.0 9.6 6.3 14 <5 1 240
0 2 14.3 10.0 6.8 14 <5 1 600
0 5 14.8 10.0 6.5 13 <5 1 500
0 3 14.7 10.1 6.7 13 <5 1 440
0 6 14.6 10.1 6.4 14 <5 1 330
0 1 14.4 9.9 6.6 14 <5 1 690
0 7 14.7 10.0 6.4 13 <5 1 510
21/07/83 0 4 14.4 9.2 6.7 23 <5 1 59
0 8 13.1 9.9 6.7 22 <5 1 66 co
100 2 14.2 9.2 6.8 23 7 27 68 N
100 5 14.6 9.2 6.6 23 <5 27 65
300 3 14.5 9.4 6.8 23 74 100 68
300 6 14.1 9.8 6.7 23 88 98 69
1000 1 14.0 9.6 6.8 27 264 320 68
1000 7 13.9 9.6 6.7 23 313 340 70
22/07/83 0 4 15.3 9.9 7.2 22 <5 1 68
0 8 13.9 10.2 7.3 22 <5 1 70
100 2 15.0 9.7 7.0 23 60 105 66
100 5 15.6 9.6 7.2 22 53 80 73
300 3 15.4 9.7 7.0 27 240 285 68
300 6 15.1 9.5 7.3 26 203 260 68
1000 1 14.9 9.8 6.8 35 860 1400 68
1000 7 14.9 9.6 7.2 35 833 1400 70
aSampled/deterrnined mid-stream.
....----,
i
APPENDIX 1 (cont'd.)
Nominal
sediment Dissolved Nonfiltrable Inflow
strength Stream Temperature oxygen Conductance residue Turbidity rate
Date (mg.L-1)no.(oC)a (mg.L-1)a pHa (umho'cm-1 )a (mg.L-1)a (FTu)a (ml'min-1 )
23/07/83 0 4 15.5 9.2 6.9 23 <5 2 72
0 8 14.1 9.6 6.7 23 <5 2 74
100 2 15.2 9.5 7.1 25 56 76 70
100 5 15.8 9.1 6.8 25 50 74 76
300 3 15.6 9.5 7.0 28 223 220 67
300 6 15.2 9.3 6.9 28 220 260 63
1000 1 14.9 9.3 7.2 36 963 1600 69
1000 7 15.0 9.4 7.2 36 863 1480 70
24/07/83 0 4 15.2 9.6 6.9 23 <5 1 71
0 8 13.8 9.8 6.9 23 <5 1 73 co
100 2 15.1 9.6 7.0 24 47 96 69 w
100 5 15.7 9.6 7.1 24 48 88 74
300 3 15.5 9.5 7.0 27 223 290 66
300 6 15.1 9.4 6.9 29 204 280 62
1000 1 15.2 9.7 7.0 38 773 1400 67
1000 7 14.8 9.8 7.0 33 893 1400 68
25/07/83 0 4 15.3 9.4 6.5 25 <5 1 71
0 8 13.8 10.5 6.7 21 <5 1 72
100 2 15.1 9.5 6.6 27 54 75 68
100 5 15.7 9.4 6.5 26 40 75 75
300 3 15.5 9.4 6.5 30 220 300 70
300 6 15.1 9.4 6.6 30 193 300 65
1000 1 14.9 9.3 6.8 37 855 1520 72
1000 7 14.6 9.6 6.3 36 870 1400 72
aSampled/determined mid-stream.
APPENDIX 1 (cont'd.)
Nominal
sediment Dissolved Nonfiltrable Inflow
strength Stream Temperature oxygen Conductance residue Turbidity rate
Date (mg·L--1 )no.(Oc)a (mg·L-1)a pHa (umho.cm-1 )a (mg.L-1)a (FTu)a (ml·min-1 )
26/07/83 0 II 15.2 9.4 6.4 27 <5 1 71
0 8 13.9 9.6 6.4 25 <5 1 72
100 2 15.0 9.5 6.5 27 64 102 69
100 5 15.7 9.4 6.4 26 56 75 74
300 3 15.4 9.4 6.5 31 200 230 70
300 6 15.2 9.5 6.5 31 180 280 64
1000 1 14.8 9.4 6.6 37 920 1400 70
1000 7 15.0 9.3 6.6 37 780 1360 7.2
27/07/83 0 4 15.2 9.6 6.5 20 <5 2 70
0 8 13.9 9.7 6.6 24 <5 2 72 co
100 2 15.0 9.5 6.5 18 60 70 70 .j:::>
100 5 15.7 9.5 6.6 21 61 95 74
300 3 15.4 9.5 6.6 19 246 330 71
300 6 15.2 9.5 6.6 22 204 270 68
1000 1 14.8 9.7 6.7 17 843 1400 72
1000 7 14.9 9.4 6.6 23 790 1400 73
28/07/83 0 4 13.7 9.9 6.6 19 <5 2 70
0 8 12.8 10.0 6.6 28 <5 3 72
100 2 14.1 9.6 6.7 20 104 115 68
100 5 14.1 9.6 6.7 21 102 145 74
300 3 14.1 9.7 6.6 22 275 490 69
300 6 14.0 9.6 6.6 19 262 600 70
1000 1 14.1 9.8 6.7 32 890 1400 71
1000 7 13.7 10.0 6.6 21 900 1400 72
aSampled/determined mid-stream.
L ..J ~f
,_...J ',J _:----,
,i
_--j
OlD,~J ,----,
c .....J
APPENDIX 1 (cont'd.)
Nominal
sediment Dissolved Nonfiltrable Inflow
strength Stream Temperature oxygen Conductance residue Turbidity rate
Date (rog.L-'I)no.(oC)a (rog·L-1)a pHa (umho·cm-1 )a (rog.L-1)a (FTU)a (ml·min-1)
29/07/83 0 4 14.9 9.4 6.6 23 <5 1 72
0 8 13.7 10.0 6.4 24 <5 2 72
100 2 14.8 9.4 6.7 23 57 75 69
100 5 15.3 9.2 6.5 24 74 110 74
300 3 15.1 9.4 6.8 27 256 360 70
300 6 14.8 9.5 6.6 27 256 340 70
1000 1 14.8 9.5 6.8 36 880 1440 72
1000 7 14.6 9.8 6.8 37 890 1600 73
30/07/83 0 4 15.7 9.5 6.4 21 <5 1 70
0 8 14.3 9.6 6.4 23 <5 1 72 co100215.5 9.3 6.l.1 22 57 85 73 U1
100 5 16.2 9.2 6.4 22 87 115 73
300 3 15.9 9.3 6.4 25 268 360 74
300 6 15.7 9.2 6.4 26 268 390 70
1000 1 15.3 9.5 6.5 34 860 1600 73
1000 7 15.4 9.3 6.6 33 847 1600 68
31/07183 0 4 15.5 9.3 6.3 23 <5 2 73
0 8 14.0 9.5 6.4 24 <5 1 72
100 2 15.3 9.3 6.4 24 78 90 70
100 5 15.9 9.4 6.4 24 100 110 69
300 3 15.7 9.3 6.5 27 282 320 70
300 6 15.3 9.6 6.5 28 256 350 68
1000 1 15.1 9.5 6.4 35 930 1560 70
1000 7 15.0 9.4 6.8 36 920 1480 66
aSampled/determined mid-stream.
APPENDIX 1 (cont'd.)
Nominal
sediment Dissolved Nonfiltrable Inflow
strength Stream Tell1perature oxygen Conductance residue Turbidity rate
Date (mg·L-1)no.(Oc)a (mg'L-1)a pHa (umho'cm-1 )a (mg.L-1)a (FTU)a (ml'min-1 )
01/08/83 0 4 15.6 9.2 6.4 24 <5 1 73
0 8 14.3 9.4 6.5 26 <5 1 70
100 2 15.5 9.4 6.4 27 94 96 69
100 5 16.1 9.2 6.5 27 105 120 70
300 3 15.8 9.2 6.6 32 290 310 68
300 6 15.5 9.3 6.6 32 293 310 65
1000 1 15.3 9.3 6.5 39 950 1480 69
1000 7 15.4 9.2 6.7 39 1080 1560 65
02/08/83 0 4 14.9 9.4 6.5 22 <5 1 73
0 8 13.8 9.8 6.5 24 <5 2 71 00100214.9 9.4 6.5 27 108 140 70 O'l
100 5 15.3 9.0 6.6 26 119 140 70
300 3 15.2 9.4 6.6 28 332 400 70
300 6 14.9 9.3 6.'7 28 294 450 69
1000 1 14.9 9.5 6.5 35 1070 1800 70
1000 '7 14.7 9.3 6.8 37 1020 1600 66
03/08/83 0 4 15.1 9.4 6.6 24 <5 1 73
0 8 13.9 9.5 6.5 27 <5 1 72
100 2 15.0 9.2 6.8 29 122 140 72
100 5 15.6 9.4 6.6 27 127 100 71
300 3 15.3 9.4 6.8 29 342 370 71
300 6 15.1 9.2 6.6 31 376 460 70
1000 1 14.9 9.6 6.8 38 1160 1800 72
1000 7 14.9 9.3 6.7 41 1030 1760 66
aSampled/determined mid-stream.
APPENDIX 1 (cont'd.)
Nominal
sediment Dissolved Nonfiltrable Inflow
strength Stream Temperature oxygen Conductance residue Turbidity rate
Date (mg.V·1)no.(oc)a (mg.L-1)a pEa (umho.cm-1 )a (mg.L-1)a (FTu)a (ml·min-1)
04/08/83 0 4 14.8 9.7 6.4 17 <5 1 71
0 8 13.7 10.0 6.4 19 <5 1 70
100 2 14.9 9.2 6.7 31 102 165 69
100 5 15.3 9.4 6.6 28 79 110 68
300 3 14.9 9.6 6.7 25 365 410 70
300 6 14.3 9.8 6.5 25 350 400 68
1000 1 13.4 10.0 6.6 36 1120 1600 70
1000 7 13.3 10.2 6.5 29 1110 1600 65
05/08/83 0 4 15.8 9.4 6.5 31 <5 1 74
0 8 14.6 9.8 6.6 31 <5 1 73 00100215.5 9.4 6.5 31 110 135 72 -.....J
100 5 16.3 9.2 6.5 29 118 90 71
300 3 15.9 9.3 6.6 30 352 450 71
300 6 15.8 9.3 6.5 30 342 425 69
1000 1 15.1 9.7 6.7 37 1190 2200 71
1000 7 15.6 9.5 6.6 39 1100 2000 67
06/08/83 0 4 15.6 9.5 6.4 25 <5 1 70
0 8
14.4 9.4 6.6 28 <5 1 78
100 2 15.4 9.3 6.5 28 131 175 75
100 5 16.1 9.3 6.5 27 146 110 76
300 3 15.8 9.4 6.7 32 350 450 75
300 6 15.6 9.5 6.5 33 342 425 72
1000 1 15.1 9.5 6.7 39 1110 2000 72
1000 7 15.4 9.3 6.8 41 1120 2000 73
aSampled/determined mid-stream.
APPENDIX 1 (corrt'd.)
Nominal
sediment Dissolved Nonfiltrable Inflow
strength Stream Temperature oxygen Conductance residue Turbidity rate
Date (mg.L-1)no.(oc)a (mg·L-1)a pHa (umho'cm-1 )a (mg.L-1)a (FTu)a (ml'min-1 )
07/08/83 ()4 15.6 9.3 6.4 23 <5 1 71
()8 14.4 9.7 6.4 23 <5 1 75
100 2 15.3 9.4 6.7 27 144 190 75
100 5 16.0 9.2 6.4 24 131 140 75
300 3 15.7 9.4 6.7 28 354 450 73
300 6 15.6 9.4 6.6 29 306 450 70
1000 1 15.1 9.6 6.9 37 1100 2000 71
1000 7 15.4 9.4 6.7 36 1060 1800 74
08/08/83 0 4 15.4 9.5 6.5 26 <5 1 72
0 8 14.1 9.6 6.4 25 <5 1 76 co
100 2 15.2 9.4 6.8 28 117 160 75 co
100 5 15.9 9.5 6.5 27 125 125 76
300 3 15.7 9.4 6.7 31 337 400 74
300 6 15.4 9.4 6.7 32 290 400 71
1000 1 15.0 9.5 6.8 37 1090 1900 72
1000 7 15.2 9.3 6.8 39 1030 1700 73
09/08/83 0 4 15.2 9.3 6.4 27 <5 1 72
0 8 13.9 9.4 6.4 24 <5 1 76
100 2 15.1 9.4 6.7 29 120 150 73
100 5 15.7 9.1 6.5 27 123 110 73
300 3 15.5 9.3 6.7 31 327 400 71
300 6 15.2 9.3 6.5 33 312 400 68
1000 1 14.9 9.4 6.7 38 1130 1900 71
1000 7 15.1 9.5 6.6 39 1060 1600 70
aSampled/determined mid-stream.
iI ,--,
L.j L J
APPENDIX 1 (cont'd.)
Nominal
sediment Dissolved Nonfiltrable Inflow
strength Stream Temperature oxygen Conductance residue Turbidity rate
Date (mg·L-1)no.(Oc)a (mg·L-1)a pHa (umho·cm-1 )a (mg.L-1)a (FTu)a (ml·min-1 )
10/08/83 0 4 15.4 9.5 6.5 26 <5 1 70
0 8 14.3 9.6 6.4 25 <5 1 76
100 2 15.2 9.4 6.6 27 99 120 73
100 5 15.8 9.2 6.5 29 95 120 75
300 3 15.6 9.4 6.6 30 334 450 73
300 6 15.4 9.3 6.5 32 380 400 70
1000 1 15.1 9.4 6.5 37 1160 2000 72
1000 7 15.3 9.4 6.5 39 1100 1920 72
11/08/83 0 4 14.9 9.5 6.4 14 <5 1 70
0 8 13.6 10.0 6.5 14 <5 1 75 co
100 2 14.6 9.7 6.5 16 117 130 72 <..0
100 5 15.1 9.5 6.6 16 105 170 72
300 3 15.1 9.4 6.5 19 303 550 71
300 6 14.3 9.8 6.5 19 313 500 69
1000 1 13.8 10.0 6.6 27 1040 2000 71
1000 7 13.3 9.8 6.6 27 1060 2200 70
12/08/83 0 4 15.4 9.4 6.4 24 <5 1 70
0 8 14.3 9.6 6.4 23 <5 1 75
100 2 15.2 9.4 6.6 29 109 105 71
100 5 15.9 9.2 6.4 30 122 130 72
300 3 15.7 9.5 6.5 31 331 390 72
300 6 15.5 9.2 6.5 29 300 400 68
1000 1 15.1 9.3 6.7 36 1080 1880 70
1000 7 15.4 9.2 6.5 39 1010 1900 71
aSampled/determined mid-stream.
APPENDIX 1 (cont'd.)
Nominal
sediment Dissolved Nonfiltrable Inflow
strength Stream Temperature oxygen Conductance residue Turbidity rate
Date (mg.L-1)no.(oc)a (mg.L-1)a pHa (umho·cm-1 )a (mg.L-1)a (FTu)a (ml·min-1 )
13/08/83 0 4 15.3 9.4 6.5 27 <5 <1 75
0 8 14.3 9.8 6.5 26 <5 <1 75
100 2 15.0 9.4 6.6 27 97 105 76
100 5 15.9 9.3 6.5 27 98 130 77
300 3 15.4 9.2 6.6 32 305 380 71
300 6 15.4 9.5 6.6 31 308 400 76
1000 1 14.8 9.5 6.6 37 1020 1680 74
1000 7 15.3 9.4 6.8 38 1010 1600 77
14/08/83 0 4 14.4 9.5 6.5 25 <5 2 74
0 8 13.6 9.9 6.5 26 <5 1 74
100 14.3 6.6 87 \.029.7 27 130 75 a
100 5 14.8 9.4 6.5 28 83 150 75
300 3 14.6 9.4 6.7 40 253 250 70
300 6 14.4 9.1 6.8 41 225 280 74
1000 1 14.4 9.7 6.7 43 850 1400 70
1000 7 14.4 9.3 6.7 43 863 1400 75
15/08/83 0 4 15.0 9.3 6.5 27 <5 <1 71
0 8 13.8 9.7 6.5 25 <5 1 72
100 2 14.9 9.3 6.6 28 99 110 73
100 5 15.5 9.1 6.5 28 120 135 74
300 3 15.2 9.3 6.6 32 271 330 69
300 6 15.0 9.3 6.5 31 282 350 71
1000 1 14.2 9.4 6.7 39 1010 1680 69
1000 7 15.0 9.4 6.7 38 905 1680 72
aSampled/determined mid-stream.
r---~L J
r -~r---""'1
!'r;I l,J""~..l.,,j
APPENDIX 1 (cont'd.)
Nominal
sediment Dissolved Nonfiltrable Inflow
strength Stream Temperature oxygen Conductance residue Turbidity rate
Date (mg.L-1)no.(oc)a (mg.L-1 )a pHa (umho'cm-1 )a (mg.L-1)a (FTu)a (ml'min-1)
16/08/83 0 4 15.1 9.2 6.5 28 <5 1 73
0 8 14.0 9.4 6.4 28 <5 1 74
100 2 15.0 9.3 6.7 29 93 125 75
100 5 15.5 9.2 6.5 29 126 150 74
300 3 15.3 9.3 6.7 32 314 400 69
300 6 15.1 9.2 6.5 32 297 400 72
100O 1 14.8 9.5 6.7 36 1010 1640 69
1000 7 15.0 9.2 6.6 38 969 1680 73
17/08/83 0 4 14.9 9.2 6.6 33 <5 1 73
0 8 13.9 9.5 6.6 29 <5 1 74 1.0
100 2 14.9 9.2 6.6 35 99 95 73 I-'
100 5 15.3 9.2 6.6 31 113 145 73
300 3 15.2 9.1 6.7 36 311 350 68
300 6 14.9 9.1 6.6 35 291 380 72
1000 1 14.8 9.2 6.7 38 1060 1680 69
1000 7 14.8 9.1 6.7 41 999 1800 73
18/08/83 0 4 14.9 9.6 6.4 20 <5 1 72
0 8 13.8 10.2 6.5 23 <5 1 74
100 2 14.8 8.9 6.6 23 101 135 74
100 5 15.2 9.3 6.5 23 116 160 72
300 3 15.2 9.3 6.6 25 349 500 68
300 6 14.6 9.6 6.5 25 283 400 72
1000 1 14.4 9.2 6.6 34 1310 2000 69
1000 7 14.2 9.8 6.6 32 1060 1600 72
aSampled/determined mid-stream.
APPENDIX 1 (cQnt'do.)
Nominal
sediment Dissolved Nonfiltrable Inflow
strength Stream Temperature oxygen Conductance residue Turbidity rate
Date (mg.L-·1 )no.(Oc)a (mg.L-1)a pHa (umho-cm-1)a (mg.L-1)a (FTU)a (ml'min-1 )
19/08/83 0 4 15.3 9.2 6.5 22 <5 1 74
0'B 14.0 9.5 6.5 23 <5 1 73
100 2 15.2 9.4 6.7 24 102 110 73
100 5 15.6 9.2 6.7 23 113 150 74
300 3 15.5 9.3 6.7 26 297 410 70
300 6 15.0 9.2 6.6 26 297 450 73
1000 1 15.1 9.4 6.7 35 972 1800 69
1000 7 14.8 9.3 6.7 33 1090 1920 74
20/08/83 0 4 15.3 9.1 6.6 27 <5 <1 76
0 8 14.3 9.6 6.5 28 <5 <1 74
6.7 74 \.0100215.2 9.5 27 110 77 N
100 5 15.7 9.2 6.6 28 95 145 78
300 3 15.5 9\1 6.7 31 261 340 73
300 6 15.3 9.3 6.6 31 255 340 74
1000 1 15.1 9.4 6.6 36 947 1720 74
1000 7 15.2 9.2 6.6 40 944 1600 74
21/08/83 0 4 15.8 9.3 6.5 31 <5 1 76
0 8 14.5 9.4 6.5 31 <5 1 75
100 2 15.5 9.2 6.6 29 62 120 75
100 5 16.2 9.0 6.5 29 85 130 76
300 3 15.9 9.2 6.6 32 281 350 72
300 6 15.7 9.1 6.6 31 256 330 74
1000 1 15.4 9.4 6.7 36 918 1600 74
1000 7 15.6 9.0 6.5 37 896 1400 73
aSampled/determined mid-stream.
r--",l :,....,j ;-j I r--]':-l r---'"'1
,.J
APPENDIX 1 (cont'd.)
Nominal
sediment Dissolved Nonfiltrable Inflow
strength Stream Temperature oxygen Conductance residue Turbidity rate
Date (mg.L-1)no.(oc)a (mg'L-1)a pHa (umho.cm-1 )a (mg.L-1 )a (FTU)a (ml·min-1)
22/08/83 0 4 14.9 9.1 6.5 32 <5 1 76
0 8 13.9 9.2 6.6 31 <5 1 74
100 2 15.0 9.3 6.6 32 91 115 73
100 5 15.3 9.0 6.5 32 105 115 72
300 3 15.2 9.3 6.6 35 307 360 70
300 6 15.0 9.0 6.5 35 283 340 70
1000 1 15.0 9.3 6.6 39 972 1520 73
1000 7 15.0 8.8 6.6 41 935 1400 72
23/08/83 0 4 15.5 9.2 6.5 32 <5 1 76
0 8 14.2 9.8 6.5 29 <5 1 73 ~
100 2 15.4 9.1 6.6 32 65 130 74 w
100 5 15.9 9.2 6.5 30 94 140 74
300 3 15.7 9.2 6.6 34 264 350 70
300 6 15.5 9.2 6.6 33 237 360 72
1000 1 15.2 9.2 6.5 37 868 1600 73
1000 7 15.4 9.2 6.7 38 854 1400 72
24/08/83 0 4 15.0 9.4 6.4 32 <5 2 76
0 8 1J.8 9.4 6.4 28 <5 1 74
100 2 15.0 9.2 6.6 31 93 120 74
100 5 15.4 9.3 6.5 31 114 165 73
300 3 15.3 9.2 6.4 33 335 450 70
300 6 14.9 9.5 6.5 33 274 380 70
1000 1 15.0 9.5 6.7 37 942 .1720 72
1000 7 14.8 9.2 6.4 37 912 1280 71
aSampled/determined mid-stream.
APPENDIX 1 (cont'd.)
Nominal
sediment Dissolved Nonfiltrable Inflow
strength Stream Temperature oxygen Conductance residue Turbidity rate
Date (mg.L,-1 )no.(OC)a (mg.L-1)a pHa (umho·cm-1 )a (mg.L-1)a (FTU)a (ml·min-1)
25/08/83 0 4 14.9 9.6 6.5 15 <5 <1 74
0 8 13.8 9.6 6.4 16 <5 1 70
100 2 14.9 9.5 6.5 18 85 140 71
100 5 15.2 9.6 6.5 18 82 160 70
300 3 15.1 9.4 6.5 20 328 450 67
300 6 14.6 9.4 6.6 20 361 50b 69
1000 1 14.6 9.5 6.6 29 1130 2000 72
1000 7 14.5 9.7 6.4 30 1130 2000 66
26/08/83 0 4 15.4 9.0 6.7 23 <5 <1 75
0 8 14.3 9'~4 6.6 21 <5 <1 73
6.8 54 125 72 <.0100215.3 9.3 21 .p,
100 5 15.8 9.0 6.6 23 68 130 72
300 3 15.5 9.4 6.8 27 216 325 69
300 6 15.3 9.2 6.7 24 226 325 70
1000 1 15.1 9.2 6.8 33 833 1500 72
1000 7 15.3 9.0 6.8 34 798 1500 71
27/08/83 ()4 15.5 9.5 6.6 27 <5 <1 76
()8 14.3 9.8 6.6 28 <5 <1 75
100 2 15.3 8.9 6.7 26 59 115 76
100 5 16.0 9.0 6.7 28 73 135 75
300 3 15.7 8.9 6.8 30 314 300 72
300 6 15.6 9.0 6.6 31 302 350 74
1000 1 15.2 8.9 6.7 37 978 1700 74
1000 7 15.4 9.1 6.7 37 876 1680 76
aSampled/determined mid-stream.
APPENDIX 1 (cont'd.)
Nominal
sediment Dissolved Nonfiltrable Inflow
strength Stream Temperature oxygen Conductance residue Turbidity rate
Date (mg.V-1 )no.(oC)a (mg·L-1)a pHa (umho·cm-1 )a (mg·L-1)a (FTU)a (ml·min-1)
28/08/83 0 4 15.1 9.6 6.5 24 <5 1 76
0 8 14.0 10.0 6.5 23 <5 <1 74
100 2 15.2 9.0 6.7 24 86 115 72
100 5 15.5 8.9 6.6 23 86 140 74
300 3 15.4 9.1 6.8 27 218 350 71
300 6 15.1 9.1 6.6 26 212 350 68
1000 1 15.2 8.9 6.6 34 933 1600 70
1000 7 15.1 9.4 6.6 33 867 1500 72
29/08/83 0 4 15.3 9.1 6.5 29 <5 <1 77
0 -8 14.2 9.2 6.6 29 <5 <1 76 <.D
100 2 15.4 9.0 6.7 29 57 105 73 (J1
100 5 15.8 8.9 6.5 30 69 110 73
300 3 15.6 9.0 6.7 36 251 270 72
300 6 15.3 9.0 6.6 34 230 325 66
1000 1 15.3 9.1 6.7 38 895 1440 70
1000 7 15.3 8.8 6.6 42 834 1200 72
30/08/83 0 4 15.5 9.1 6.6 28 <5 <1 75
0 8 14.3 9.3 6.6 25 <5 <1 73
100 2 15.3 9.1 6.7 30 58 115 72
100 5 15.9 9.0 6.6 29 64 110 73
300 3 15.7 9.1 6.8 34 197 230 71
300 6 15.5 9.0 6.6 32 206 300 66
1000 1 15.3 9.4 6.9 35 820 1400 70
1000 7 15.5 9.0 6.6 39 779 1200 72
aSampled/determined mid-stream.
APPENDIX 1 (oont"d.•)""',
Nominal
sediment Dissolved Nonfiltrable Inflow
strength Stream Temperature oxygen Conductance residue Turbidity rate
Date (mg'L-l)no.(oc)a (mg.L-l)a pHa (umho'cm-1)a (mg.L-l)a (FTU)a (ml'min-1)
31/08/83 0 4 15.2 9.5 6.6 28 <5 <1 76
0 8 14.1 9.8 6.6 25 <5 <1 76
100 2 15.1 9.7 6.6 29 76 125 72
100 5 15.6 9.5 6.5 29 85 125 72
300 3 15.4 9.5 6.6 33 277 260 69
300 6 15.2 9.5 6.7 32 255 325 65
1000 1 15.0 9.9 6.6 38 990 1400 69
1000 7 15.1 9.3 6.7 39 859 1400 70
01/09/83 0 4 15.1 9.9 6.4 35 <5 <1 75 .
0 8 14.1 10.6 6.6 30 <5 <1 77 ~100 2 15.2 9.8 6.4 36 55 110 72 O"'l
100 5 15.5 9.9 6.5 35 66 115 72
300 3 15.,4 9.9 6.5 37 217 300 69
300 6 15.0 9.9 6.5 39 253 340 64
1000 1 15.2 9.9 6.4 49 855 1400 69
1000 7 15.0 9.8 6.5 50 846 1360 70
aSampled/determined mid-stream.