HomeMy WebLinkAboutAPA2647Effects on Arctic Grayling
(Thymallus arctlcus) of Short-Term
. .
Exposure to Yukon Placer Mining
Sediments: Laboratory ·and Field
Studies
D. J. Mcleay, A. J. Knox~ J. G. Malick,
I. K. Birtwell, G. Hartman, and G. L. -Ennis
:Department of Fisheries and Oceans
Fisheries Research Branch ·
West Vancouver Laboratory
4160 Marine Drive
West Vancouver, British Columbia V7V 1 N6
• 0
May 1983
Canadian Technical Report of
Fisheries and Aquatic Sciences
N.o. 1171
ment of Canada Gouvernement du Canada
s and Oceans Peches et Oceans
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Canadian Technical Report of Fisheries
and Aquatic Sciences No. 1171
Yukon River Basin Study
Fisheries Project Report No. 2
May 1983
EFFECTS ON ARCTIC GRAYLING
(Thymallus arcticus)
OF SHORT-TERM EXPOSURE TO
YUKON PLACER HINING SEDIMENTS:
LABORATORY AND FIELD STUDIES
by
D.J. McLeay 1 , A.J. Knox 2 , J.G. Malick2 ,
I.K. Birtwell3a, G. Hartman3b and G.L. Ennis3c
1 n. McLeay & Associates Ltd., Suite 300, 1497 Marine Drive,
West Vancouver, B. C. V7T 1B8
2 Norecol Environmental Consultants Ltd., Suite 100, 1281 West Georgia St.,
Vancouver, B. C. V6E 3J7
3 Fisheries and Oceans Canada
a) Salmon Habitat Section, Fisheries Research Branch, West Vancouver
Laboratory, 4160 Marine Drive, West Vancouver, B. C. V7V 1N6
b) Salmon Habitat Section, Fisheries Research Branch, Pacific
Biological Station, Nanaimo, B. C. V9R 2Pl
c) Habitat Management Division, Field Services Branch,
1090 West Pender Street, Vancouver, B. C. V6E 2Pl
-11 -
(c) Minister of Supply and Services Canada 1983
Cat. No. Fs 97-6/1171 ISSN 0706-6457
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PREFACE
These studies,with other preliminary work on food habits and the distribu-
tion of Arctic grayling,were carried out to provide some initial information ~n
the effects of placer mining sediments on this species of fish.At the time the
1982 field work was plan~ed,it was anticipated that a longer term programme of
more comprehens ive studies on the effects of sediment on various stages in the
life cycle of grayling and their habitat would follow.While this work was
directed primarily at sediment impacts on juvenile grayling,it was also
recognized that a sound understanding of the ecology of the species is needed for
management purposes.
Sensitive and well informed management of water resources,and the associated
protection of fisheries values,will require much more research on the effects of
sediment impacts on a wide variety of biological processes.Such research will
require elucidation of the effects of,for example,the concentration of sediment,
size,shape and hardness of particles,mixes of particle types and timing of
discharge.Studies on many of these factors should be carried out on fish at
various stages in their life cycle and in different seasons.In addition,studies
on the effects of sediment and sediment characteristics on rheotactic behaviour,
feeding behaviour,spawning behaviour,and the production of food organisms for
fish;are required to support sound water use planning.Although it may be
desirable to have information on this scale now for water resource decisions,it
is not realistic to expect it after one year of research.
It is hoped that the work done in 1982,and considered in total,may be of
value to the agencies that manage water resources for the public of Yukon.
However,the authors would warn people not to use single components of the
results to form guiding principles in water use decision making.For example,
acute lethal bioassay tests,performed in otherwise protected conditions,do not
in themselves indicate the effect of much lower concentrations of sediment on
grayling in the wild which must find food,avoid predators,and maintain
positions in a stream system over a prolonged period.Other species of fish have
been shown to be able to tolerate exposure,in protected conditions,to short-term
high concentrations of sediment.It has also been shown that the same species are
affected adversely by much lower concentrations of sediment where physiological
tests are considered or where reproduction and feeding are involved.
Part.s of the work we carried out in 1982 indicate the nature of certain
physiological responses of fish to suspended sediment.Other components
investigated the distribution and food of grayling in a stream system receiving
sediment from placer mining operations;the results of this work will be reported
separately.
In this Preface the authors are not apologizing for the scale or quality of
these initial studies.We are urging caution in interpretation and application of
such first-stage research.In a broad sense we are stressing the need to
understand cold-zone stream ecology,grayling biology,and the complex effects of
various components of placer mining on them.
The Department of Fisheries and Oceans (Fisheries Research Branch and Field
Services Branch)and the Yukon River Basin Study (a joint study by Canada,Yukon
and British Columbia of the water and related resources of the Yukon basin)funded
this project.Opinions expressed are those of the authors.The work was a
co-operative undertaking by D.McLeay &Associates Ltd.,Noreco1 Environmental
Consultants Ltd.,and staff of the Department of Fisheries and Oceans.The study
also relied upon the co-operation of placer miners along Highet Creek,within the
Minto Creek drainage.
iv
TABLE OF CONTENTS
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List of Tables .•
List of Figures ••••...............................'.
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1S Q C.
SaC •.
tests.
1S o C.
List of Appendices .
Abs tr ac t IRe-sume .
Introduction ..•••
Materials and Methods.
Laboratory Studies ..
Fish collection ...
Fish rearing .•••.•
Sediment collection...••.•.•••••••
Sediment preparation and analyses ..
Recycle test tanks •••.
Acute survival tests •.
Fish acclimated to
Fish acclimated to
Temperature tolerance
Fish acclimated to
Fish acclimated to SoC .•
Sealed jar bioassays .•.•••••
Fish acclimated to 15°C •.••••••
Fish acclimated to SaC.
Acute stress bioassays ••..
Reference toxicant tests ••
Statistical analyses.
Field Studies ••.
Study area •••••••.
General .
Highet Creek .•
Minto Creek •..
Fish collection •.
In~situ bioassays ..
Test apparatus ..
Water quality ••
Experimental •••
Results and Discussion.
Laboratory Studies •.•.....••••.•.•.
Fish growth and condition ••
Characteristics of test sediment •••
Acute survival and gill histology ••
Temperature tolerance tests.
Sealed jar bioassays •.•
Acute stress bioassays.
General ...........••.••
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TABLE OF CONTENTS (CONT.)
·.
Field Studies •.••••
Water quality .•.
Caged fish studies.
Fish survival..
Gill histology.
Hematology .•••••
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Conclusions •••••.
Acknowledgements.
References .•.•..•
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Table
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-vi -
LIST OF TABLES
Particle size distribution for paydirt and overburden
sediment samples.
Moisture content,volatile and fixed residue,and oxygen
uptake rate for paydirt and overburden sediment samples.
Metal content of paydirt and overburden sediment samples.
Effect of location within recycle test tanks on concen-
tration (total residue values)of recirculating paydirt
sediment.
Acute survival test:Effect of a 4-day exposure to sus-
pended inorganic paydirt fines on fish survival and on
blood sugar and hematocrit values for underyear1ing
Arctic grayling acclimated to lSoC.
Acute survival test:Effect of a 4-day exposure to
suspended organic overburden on fish survival and on
blood sugar and hematocrit values for underyear1ing
Arctic grayling acclimated to lSoC.
Acute survival test:Effect of a 4-day exposure to sus-
pended inorganic paydirt fines on fish survival and on
blood sugar,1eucocrit and hematocrit values for under-
yearling Arctic grayling acclimated to SoC.
Temperature tolerance test:Effect of suspended inorganic
paydirt"on the critical thermal maxima forunderyear1ing
Arctic grayling acclimated to lSoC.
Temperature tolerance test:Effect of suspended organic
overburden on the critical thermal maxima for underyear-
ling Arctic grayling acclimated to lSoC.
Temperature tolerance test:Effect of pentachlorophenol
on the critical thermal maxima for underyear1ing Arctic
grayling acclimated to lSoC.
Temperature tolerance test:Effect of suspended inorganic
paydirt on the critical thermal maxima for underyear1ing
Arctic grayling acclimated to SoC.
Sealed jar bioassay:Effect of suspended inorganic pay-
dirt on tolerance to hypoxia and time to hypoxic death
for underyear1ing Arctic grayling acclimated to lSoC.
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Table
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-vii -
LIST OF TABLES (CONT.)
Sealed jar bioassay:Effect of suspended inorganic
paydirt on tolerance to hypoxia and time to hypoxic
death for underyearling Arctic grayling acclimated
to 5°C.
Sealed jar bioassay:Effect of suspended organic
overburden on tolerance to hypoxia and time to
hypoxic death for underyearling Arctic grayling
acclimated to 15°C.
Sealed jar bioassay:Effect of pentachlorophenol on
tolerance to hypoxia and time to hypoxic death for
underyearling Arctic grayling acclimated to 15°C.
Acute stress bioassay:Effect of suspended inorganic
paydirt on blood sugar,hematocrit and leucocrit
values for underyearling Arctic grayling acclimated
to 15°C.
Acute stress bioassay:Effect of suspended organic
overburden on blood sugar,hematocrit and leucocrit
values for underyearling Arctic grayling acclimated
to 15°C.
Acute stress bioassay:Effect of pentachlorophenol
on blood sugar,hematocrit and leucocrit values for
°underyearling Arctic grayling acclimated to 15 C.
Summary of threshold-effect concentrations of paydirt
or overburden suspensions causing acute responses for
Arctic grayling.
Water quality characteristics monitored at test site
in Highet Creek and the control site in Minto Creek
during the fish enclosure tests,August and September,
1982.
Hardness,alkalinity and metal content (mgoL-1 )
determined for water samples taken from Highet,Minto
and Mud creeks during the fish enclosure tests,
August and September,1982.
Table
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-viii -
LIST OF TABLES (CONT.)
Particle size distribution for suspended sediment
sampled from Highet Creek during August and
September,1982.
Percentage survival of underyearling Arctic gray-
ling held in Highet Creek or Minto Creek for 4-5
days during August or September,1982.
Gill histopathologies for underyearling Arctic
grayling held in Minto Creek or Highet Creek
during September 1982.
Mean (±SD)biological characteristics of underyear-
ling Arctic grayling sampled from cages or directly
from creeks during August and September,1982.
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LIST OF FIGURES
Figure
1 Illustration of recycle test tanks.
2 Illustration of derivation of hematocrit and leucocrit
values from a centrifuged blood sample within a heparin-
ized glass capillary tube.
3 Map of site for in-situ caged fish studies.
4 Schematic drawing of net enclosures for in-situ caged
fish studies.
S Study site at Minto Creek.Fish enclosures are shown
in-situ.
6 Study site at Highet Creek.Fish enclosures are shown
in-situ.
7 Relationship of total residue,nonfiltrable residue and
turbidity for suspensions of paydirt sediment in fresh-
water.
8 Relationship of total residue,nonfiltrable residue and
turbidity for suspensions of overburden sediment in
freshwater.
9 Illustration of the stability of differing concentrations
of suspended paydirt fines within recycle test tanks
during a 96-h bioassay.
10 Relationship of concentration of suspended inorganic pay-
dirt to critical thermal maxima for underyearling Arctic
grayling acclimated to lSoC.
11 Relationship of concentration of suspended organic over-
burden to critical thermal maxima for underyearling
Arctic grayling acclimated to lSoC.
12 Relationship of concentration of suspended inorganic pay-
dirt to critical thermal maxima for underyearling Arctic
grayling acclimated to SoC.
13 Relationship of concentration of inorganic paydirt to
time to death in sealed jar bioassays for underyearling
Arctic grayling acclimated to lSoC and tested at 20°C.
Figure
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LIST OF FIGURES (CaNT.)
Relationship of concentration of inorganic paydirt
to tolerance to hypoxia in sealed jar bioassays for
underyear1ing Arctic grayling acclimated to lSoC
and tested at 20°C.
Relationship of concentration of inorganic paydirt to
time to death in sealed jar bioassays for underyear-
ling Arctic grayling acclimated to SoC and tested at
10°C.
Relationship of concentration of inorganic paydirt
to tolerance to hypoxia in sealed jar bioassays for
underyear1ing Arctic grayling acclimated to SoC and
tested at 10°C.
Relationship of concentration of organic overburden
to time to death in sealed jar bioassays for under-
yearling Arctic grayling acclimated to lSoC and
tested at 20°C.
Relationship of concentration of organic overburden
to tolerance to hypoxia in sealed jar bioassays for
underyear1ing Arctic grayling acclimated to lSoC and
tested at 20°C.
Relationship of concentration of suspended inorganic
paydirt to blood 1eucocrit values for underyear1ing
Arctic grayling acclimated to lSoC and exposed to
sediment for 24 h.
Relationship of concentration of suspended organic
overburden to blood 1eucocrit values for underyear-
ling Arctic grayling acclimated to lSoC and exposed
to sediment for 24 h.
Relationship of concentration of suspended inorganic
paydirt to blood sugar values for underyear1ing
Arctic grayling acclimated to lSoC and exposed to
sediment for 24 h.
Relationship of concentration of suspended organic
overburden to blood sugar values for underyear1ing
Arctic grayling acclimated to lSoC and exposed to
sediment for 24 h.
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-xi -
LIST OF FIGURES (CONT.)
Relationship of concentration of suspended inorganic paydirt
to blood sugar values for underyearling Arctic grayling
acclimated to 5°C and exposed to sediment for 96 h.
Illustration of concentration of suspended sediment (total
residue)and turbidity within cages held in Highet Creek
during August 1982.
Illustration of concentration of suspended sediment (total
residue)and turbidity within cages held in Highet Creek
during September 1982.
Gill filaments of underyearling Arctic grayling·captured
from Minto Creek during September 1982.Note normal
appearance of secondary lamellae (a).300X.
Gill filaments of underyearling Arctic grayling captured
from Minto Creek and held in a cage within Minto Creek for 5
days during September 1982.Note moderate hypertrophy
(increase in cell size)and hyperplasia (increase in cell
numl;>ers .of lamellar epithelium (b),and presence of large
numbers of ectoparasites (c).300X.
Appendix
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LIST OF APPENDICES
Summary of the aquatic biophysical characteristics for
the Highet Creek and Minto Creek caged fish sites during
August and September 1982.
Physical/chemical characteristics during 4-day survival
test with lSoC-acc1imated underyear1ing Arctic grayling
exposed to inorganic paydirt suspensions.
Physical/chemical characteristics during 4-day survival
test with lSoC-acc1imated underyear1ing Arctic grayling
exposed to organic overburden suspensions.
Physical/chemical characteristics during4-day survival
test with SOC-acclimated underyear1ingArctic grayling
exposed to inorganic paydirt suspensions.
Residue and turbidity values within a cage held in Highet
Creek during the August 1982 in-situ fish survival test.
Residue and turbidity values within a cage held in Highet
Creek during the September 1982 in-situ fish survival
test.
Residue and turbidity values within a cage held in Minto
Creek during the August 1982 in-situ fish survival test.
Residue and turbidity values within a cage held in Minto
Creek during the September 1982 in-situ fish survival
tes.
Comparison of suspended sediment and turbidity values
for triplicate water samples taken from within or out-
side of a Highet Creek cage during the August and
September 1982 in-situ fish survival tests.
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ABSTRACT
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 mining sediments:laboratory and field studies.Can.Tech.Rep.
Fish.Aquatic Sci.1171:xvii +134 p °
A program of controlled laboratory and in-situ field bioassays was conducted
during 1982/83 to examine the acute effects Of·suspensions of Yukon placer mining
sediment on underyearling Arctic grayling (Thymallus arcticus).wild grayling,
captured as swimup fry or young fingerlings,were acclimated to warmwater (lSOC)
or coldwater (SOC)conditions for 7-12 weeks,and subjected to a range of
concentrations of organic sediment (overburden)and/or inorganic sediment
(paydirt)suspensions in recirculating test tanks.On two occasions (August and
September 1982),grayling fingerlings were captured from central Yukon clearwater
streams and held for 4 or S days in cages within turbid creekwater (Highet Creek)
downstream of placer mining activities,and at a nearby clearwater site (Minto
Creek upstream of its junction with Highet Creek).
Laboratory-reared grayling acclimated to lSoC survived a 4-day exposure to
inorganic sediment suspensions <2S0,000 mgoL-l,and a l6-day exposure to SO,OOO
mg °L -1.These fish also survived acute (4-day)exposure to all strengths of
organic sediment examined «SO,OOO mgoL-l).All fish acclimated to SoC and held
in paydirt suspensions <10,000 mgoL-l survived for 4 days,whereas 10-20%
mortalities occurred in the higher strengths examined.
Inorganic sediment strengths >10,000 mgoL-l caused fish to surface,a direct
response to elevated sediment levels.No other behavioural anomalies were
evident.Other signs of fish distress or damage were not observed for any
grayling surviving exposure to either sediment type.The gill histology of fish
surviving these 4-day exposures was normal.
The tolerance of laboratory-reared grayling to temperature extremes (critical
thermal maxima)was not impaired appreciably by either sediment type.Slight but
consistent declines in critical thermal maxima were noted for warmwater-acclimated
fish held in inorganic or organic sediment strengths >SOO mg °L -1 and >S ,000
mgoL-l,respectively,whereas changes in thermal tolerance-were not found for fish
acclimated to cold water and held in high strengths of inorganic sediment.
The acute tolerance of warmwater-or coldwater-acclimated fish to hypoxic
conditions (oxygen deficiency)in sealed jar bioassays was not impaired by
suspended sediment.Tests with overburden suspensions showed a decreased time to
death in these bioassays,which was attributed to the sediment I s oxygen demand.
High concentrations of paydirt increased time to death (decreased respiratory
rate)in sealed jar bioassays for the warmwater-acclimated fish only.
Suspensions of inorganic and organic sediment caused acute stress responses
(elevated and/or more varied blood sugar levels,depressed leucocrit levels)for
grayling acclimated to either temperature.Responses were noted for sediment
-xiv -[
strengths as low as 50 mgoL-l (overburden),although confirmation of threshold-
effect levels requires further studies.Hematocrit values for these fish were not
affected by sediment.
Acute (short-term)effects toward Arctic grayling of the reference toxicant
pentachlorophenol were examined in laboratory biossays.Median lethal
concentrations were similar to those found previously with this aquatic
contaminant and other species of salmonid fish,and were not affected by
acclimation temperatures.The effects on grayling of sublethal strengths of
pentachlorophenol noted for temperature tolerance tests,sealed jar bioassays and
acute stress bioassays were also similar to those determined before with other
juvenile salmonids.
During the August field bioassays,all grayling held in Highet Creek
(suspended solids <l00 mgoL-l)or Minto Creek (suspended solids <20 mgoL-l)for 4
days survived,with no overt signs of distress or physical damage.In September,
all fish captured from Minto Creek and held in cages within Highet Creek
(suspended solids <1,210 mgoL-1 )or Minto Creek (suspended solids <34 mgoL-1 )for
5 d~ys also survived.\Gill tissues of fish sampled in September from cages at
each site showed moderate-to-marked hypertrophy and hyperplasia of lamellar
epithelium,together with a proliferative number of gill ectoparasites.No
histopathological differences were found between sites.The gill histology of
uncaged grayl ing sampled directly from Minto Creek upstream of Highet Creek was
kormal,although occasional ectoparasites were observed.
I All grayling captured from Mud Creek (a clearwater tributary of Minto Creek)
and held for the same 5-day period during September in cages within Minto Creek
survived;whereas 16%(5 {'4}f 32 fish)of the Mud Creek fish held at this time in
Highet Creek',died wi thiriJ 96 h.The cause of these deaths was attributed to an
intolerable stess loadin imposed by the combined effects of fish capture,
transport,confinement and exposure to suspended sediment and temperaure
fluctuations'within Highe Creek.
Although hematocri values measured for fish caged at either site were
I
similar,mean plasma g\ilcose values for fish held for 4 days within Highet Creek
during August were ele~~ted 30%from values for fish caged in Minto Creek at this
time.During SeptemD~r,grayling captured from either Minto Creek or Mud Creek
and caged in Highet Creek showed a 100%increase in mean plasma glucose levels,
relative to values for corresponding groups held in Minto Creek.These
differences were thought to be caused by the more stressful water quality
conditions (suspended sediment loadings and/or more extreme temperature
differences)within Highet Creek,compared with the Minto Creek site.
It was concluded that the short-term exposure of Arctic grayling to sublethal
concentrations of suspended inorganic or organic sediment can cause a number of
effects including acute stress responses.In light of these findings,the
environmental impact of placer mining sediments on the immediate and long-term
adaptive capabilities (including feeding and other behavioural responses,disease
resistance,growth and chronic well-being)of this sensitive fish species needs to
be more fully understood.
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-xv -
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 e4xposure to Yukon placer mining sediments:Laboratory and
field studies.Can.Tech.Rep.Fish.Aquat.Sci.1171:xvii +134 p.
Le present rapport porte sur un programme de bio-essais contrOles en
laboratoire et sur Ie terrain menes en 1982-1983 afin d'etudier les effets
aigus de sediments en suspension provenant de l'exploitation de gisements
alluvionnaires au Yukon sur des individus de mains d'un an d'ombre arctique
(Thymallus arcticus).Des ombres sauvages,capturees au stade d'alevins
nageurs ou jeunes digitales,ont ete acclimatees a l'eau chaude (1S0C)ou
froide (5°C)pendant 7 a 12 semaines et soumises a une gamme de concentrations
de sediments organiques (morts-terrains de recouvrement)et inorganiques
(riches graviers aurifares)en suspension dans des bassins d'essai a renvoi.
Des digitales ont ete prises dans des ruisseaux d'eau claire du Yukon central,
soit en aoOt et en septembre,et maintenues pendant 4 ou 5 jours dans des
cages placees dans l'eau turbide du ruisseau Highet en aval de l'exploitation
miniare alluvionnaire et dans l'eau claire du ruisseau Minto,en amont de sa
jonction avec Ie ruisseau Highet.
Les ombres elevees en laboratoire et acclimatees a 1Soc ont survecu
a une exposition de 4 jours a des sediments organiques en suspension <2S0 000
mg.L-1 et de 16 jours a 50 000 mg.L-1.Ces poissons ont aussi survecu a une
exposition aigue (4 jours)a toutes les concentrations de sediments organiques
testees «SO 000 mg L-1).Tous les individus acclimates a soC et gardes dans
des suspensions d'alluvions exploitables <10 000 mg.L-1 ont survecu pendant 4
jours alors que la mortalite variait de 10 a 12 %en presence de
concentrations plus elevees.
Des concentrations de sediments inorganiques >10 000 mg.L-1
forcaient les poissons a faire surface,ce qui represente une reaction directe
a des niveaux eleves de sediments.Aucune autre anomalie de comportement n'a
ete notee.Aucun signe d'epuisement ou de dommage n'a ete remarque chez les
ombres qui ont survecu a une exposition aux deux types de sediments.Les
preparations histologiques des ouies de poissons apras 4 jours d'exposition ne
revelaient aucune anomalie.
La tolerance des ombres elevees en laboratoire aux extr~mes
thermiques (maximums thermiques critiques)n'a pas ete grandement diminuee par
les deux types de sediments.Des baisses faibles mais constantes des maximums
thermiques critiques ont ete notees chez les poissons acclimates a l'eau
chaude et maintenus dans des concentrations de sediments organiques et
inorganiques >SOO mg.L-1 et > S 000 mg.L-1 respeetivement elors que des
variations de-Ia tolerance thermique n'ont pas ete decouvertes chez les
poissons acclimates a l'eau froide et maintenus dans des concentrations
elevees de sediments inorganiques.
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La tolerance aigue des poissons acclimates a l'eau chaude et froide
aux conditions hypoxiques (carence d'oxygene)pendant des bio-essais menes
dans des bocaux scelles n'a pas ete reduite par les sediments en suspension.
En presence de suspensions de morts-terrains de recouvrement,la mort etait
plus rapide a cause de la demande en oxygene des sediments.Des
concentrations elevees d'alluvions exploitables retardaient la mort (taux de
respiration abaisse)des poissons acclimates a l'eau chaude seulement.
Des suspensions de sediments inorganiques et organiques causaient
des reactions de stress aigu (niveaux de sucre sanquin eleves au plus
variables et niveaux abaisses de leucocrites)chez-les ombres acclimatees aux
deux temperatures.Les reactions aux concentrations de sediments aussi
faibles que 50 mg.L-1 (morts-terrains de recouvrement)ant ete notees quai que
une confirmation des niveaux de seuil requiere des etudes plus poussees.Les
valeurs de l'hematocrite chez ces poissons n'etaient pas affectees par la
presence de sediments.
On a aussi etudie l'incidence aigue (8 court terme)d'une substance
toxique etalon,Ie pentachlorophenol,sur l'ombre arctique au cours de
bio-essais en laboratoire.Les concentrations letales medianes de ce
contaminant aquatique,semblables a celles notees precedemment chez d'autres
especes de salmonides,n'etaient pas touchees par les temperatures
d'acclimatation.Les effets de concentrations subletales de pentachlorophenol
sur les ombres,notes pendant des tests de tolerance thermique,des bio-essais
en bocaux scelles et des analyses biologiques du stress aigu,etaient
semblables a ceux determines auparavant chez d'autres salmonides juveniles.
Pendant les bio-essais sur Ie terrain menes en aoOt,toutes les
ombres gardees dans Ie ruisseau Highet (solides en suspension <100 mg.L-1)et
Ie ruisseau Minto (solides en suspension <20 mg.L-1)pendant 4-jours ant
survecu sans signes evidents d'epuisement-ou de dommage physique.En
septembre,taus les poissons captures dans Ie ruisseau Minto et maintenus dans
des cages dans Ie ruisseau Highet (solides en suspension <1 210 mg.L-1)au Ie
ruisseau Minto (solides en suspension <34 mg.L-1)pendant-5 jours avaient
aussi survecu.Des echantillons d'ouies de poissons recueillis en septembre
dans les cages de chaque site indiquaient une hypertrophie variant de moderee
a marquee et une hyperplasie de l'epithelium lamellaire,en plus d'une
proliferation numerique des ectoparasites des ouies.II n'y avait aucune
difference histopathologique entre les deux endroits.Les preparations
histologiques d'ouies d'ombres en liberte capturees dans Ie ruisseau Minto en
amant du ruisseau Highet etaient normales quoiqu'on ait releve la presence
occasionnelle d'ectoparasites.
Toutes les ombres prises dans Ie ruisseau Mud (un tributaire d'eau
claire du ruisseau Minto)et maintenues dans des cages dans Ie ruisseau Minto
pendant la m~me periode de 5 jours en septembreont survecu tandis que 16 %
des poissons (5 sur 32)du ruisseau Mud maintenus pendant ce temps dans Ie
ruisseau Highet sont marts en mains de 96 h.On attribue cette mortalite 8
une charge intolerable de stress decoulant des effets combines de la capture,
du transport,de la mise en captivite et de l'exposition 8 des sediments en
suspension et a des variations de temperature dans Ie ruisseau Highet.
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Quoique les valeurs d'hematocrite quantifiees chez les poissons en
cage aux deux sites etaient semblables,les valeurs moyennes du glucose dans
Ie plasma chez les poissons maintenus pendant 4 jours dans Ie ruisseau Highet
en aoQt etaient de 30 %superieures a celles des specimens gardes dans Ie
ruisseau Minto au meme moment.En septembre,des ombres capturees dans les
ruisseaux Minto et Mud et mises en cage dans Ie ruisseau Highet ont subi une
augmentation de 100 %des niveaux moyens de glucose dans Ie plasma par rapport
aux valeurs du groupe correspondant garde dans Ie ruisseau Minto.On croit
que ces differences tiennent aux conditions aquatiques plus stressantes
(charges de sediments en suspension et differences de temperature plus
prononcees)dans Ie ruisseau Highet par rapport au ruisseau Minto.
On conclut que l'exposition a court terme de l'omble arctique a des
concentrations subletales de sediments organiques ou inorganiques en
suspension peut causer un certain nombre d'effets y compris des reactions de
stress aigu.Tenant compte de ces decouvertes,il est necessaire de mieux
comprendre l'incidence environnmentale des sediments provenant d'exploitation
de gisements alluvionnaires sur les capacites d'adaptation immediate et a long
terme (y compris l'alimentation et les autres reactions de comportement,la
resistance aux maladies,la croissance et Ie bien-etre chronique)de cette
espece de poisson sensible.
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INTRODUCTION
Placer mining activity in Yukon Territory has increased appreciably during
the past few years.The exact impact of current and past mining operations on the
fisheries resources in the Pacific and Yukon Region is not clearly understood;
however,recent studies have shown site-specific evidence of damage to aquatic
life and habitat (Mathers et al.1981;Singleton et al.1981;Weagle 1982).
Adverse effects attributed to suspended and deposited sediment loads in
receiving waters downstream of placer mining activities include degraded water
quality (Knapp 1975;Anon.1981;Mathers et a1.1981);reduced numbers of benthic
invertebrates (Anon.1979a;Mathers et al.1981);habitat disruptions and reduced
numbers of Arctic grayling (Thymallus arcticus)and other fish species (Knapp
in prep.;Anon.1979;Weir 1979;Mathers et al.1981;Singleton et al.1981;
Weagle 1982).Despite.this evidence of threat to Yukon fisheries,present data
concerning direc t evidence for the deleterious effects of suspended sediment on
grayling and other sensitive aquatic species native to these waters are
insufficient to permit a clear understanding of the impact of placer mining
sediments on Arctic grayling.
Earlier studies (Herbert and Merkens 1961;Anon.1965;Neumann et al.1975;
O'Connor et al.1977;Noggle 1978)have reported that sediment suspended in water
can cause acute lethal or sublethal effects toward fish.Although some
non-salmonid fish species have been shown to survive short-term exposures to
suspended sediment strengths as high as 100,000 mg·L-1 (Wallen 1951),bioassays
conducted by Noggle (978)indicated that salmonid fish tolerance to natural
stream sediment varied seasonally and that suspended sediment concentrations as
low as 1,200 mg~L-1 could be acutely lethal to underyearling salmonid fish.
Additionally,Noggle's (1978)findings demonstrated that lower sediment strengths
could be stressful to these fish.
The present studies were undertaken to provide an understanding of the acute
lethal tolerance of Arctic grayling to placer m~n~ng sediment under both
laboratory and field conditions;and to determine if short-term exposures to
sublethal sediment strengths caused certain deleterious effects (gill
histopathologies,impaired respiratory capacity,reduced tolerance to temperature
extremes,stress responses)to these fish.The influence on these responses of
differing sediment types (inorganic "paydirt"fines and organic "overburden"soil)
found suspended in stream water as a result of placer mining activities (Anon.
1981;Emond 1982),and of seasonal changes in photoperiod and water temperature to
which Arctic grayling were acclimated,were also examined in laboratory tests.
The acute lethal and sublethal responses of laboratory-reared grayling to the
reference toxicant pentachlorophenol (Davis and Hoos 1975)were determined in
concurrent bioassays in order to relate the nature and extent of effects to those
ascertained for other salmonid fish species with this contaminant.
The acute bioassay tests to which these gray1 ing were subjected were based
upon procedures developed previously for evaluating the short-term impact toward
salmonid fish of a variety of aquatic contaminants or other environmental
stressors (McLeay and Gordon 1980;Wedemeyer and McLeay 1980.As part of this
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investigation,short-term in-situ bioassays were conducted on each of two
occasions (August and September 1982)with wild underyearling grayling held
captive in a Yukon clearwater stream (Minto Creek),and in a tributary stream
(Highet Creek)downstream of active placer m1n1ng..It was hoped that these
laboratory and field studies would provide a better understanding concerning the
direct effects of placer mining sediments on the acute tolerance and short-term
adaptive capabilities of juvenile Arctic grayling.
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MATERIALS AND METHODS
LABORATORY STUDIES [
Fish collection
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young-of-the-year Arctic
waters within the Yukon
These fish,captured by
fry)to 5.0 cm (l-g young
Upon capture,fish were placed in plastic "laundry"baskets lined with
fibreglass mesh screen,and held in the stream from which they were seined until
sufficient numbers (800-1,000)were collected for shipment.Groups of 50-100
individuals were placed in creekwater within 20-L plastic bags,and provided with
an oxygen atmosphere (cylinder 02).These water bags were placed in coolers and
packed with ice at the earliest opportunity.Fish were trucked to Whitehorse
(Yukon Territory)and air-expressed to Vancouver for the controlled laboratory
bioassays.A total of five separate shipments were made.
A heterogeneous population of approximately 5,000
grayling were collected from northern British Columbia
River drainage basin during July and August,1982.
seining,ranged in size from 1.5 cm (0.03-g swimup
fingerlings),depending on collection site and time.
Fish rearing
Upon receipt at the Vancouver laboratory (B.C.Research),fish were
transferred to an outside fibreglass hatchery trough (swimup fry)or to four
outside 1000-L semicircular fibreglass tanks (fingerlings).Water supply to these
tanks was Vancouver City dechlorinated tap water,heated and regulated to a
constant temperature of 150 +1 0 C.The minimum water exchange rate to each tank
was 2 L"g-l fish per day throughout the duration of this study.Additionally,
fish-loading density in each tank was held below 2.5 g"L-1 to ensure that grayling
were not overcrowded (Sprague 1973).
Initially,fish were fed Biodiet No.1 (0.6 mm crumble size;Bioproducts
Inc.,Warrenton,Ore.)supplemented with live brine shrimp.Food was offered 8-10
times daily,and trough/tanks siphoned daily to remove excess food and faeces.
Due to difficulties encountered in encouraging the younger (swimup fry)grayling
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to feed,the trough-reared fish were also offered finely-ground beef heart,
freeze-dried pulverized tubifex worms,live daphnia (Daphnia pulex),Oregon Moist
mash and canned salmon.
Feed crumble size was increased to 0.6-0.8 mm (Biodiet NO.2)during late
August.This ration was gradually replaced with Oregon Moist pellets (OMP;1.6
mm)supplemented with twice-weekly feeds of live brine shrimp.
Fish were size-sorted and transferred to clean tanks at 4 to 6 week
intervals.Water temperature to which these fish were acclimated was maintained
at 150 +1 0 C until December 1 (i.e.until all bioassays with IS oC-acclimated fish
were completed).At this time,the water temperature within each of three outdoor
tanks holding the remaining stock of grayling was decreased gradually (2 0 c day-I)
using increasing flow rates of untempered (50 +O.SOC)Vancouver City
dechlorinated tap water,until this colder temperature was attained.Grayling
were acclimated to this water temperature for a 7-week period prior to the final
series of bioassay tests.Throughout this period,fish were fed twice daily an
excess ration of OMP together with freshly thawed sockeye salmon (Oncorhynchus
nerka)eggs.
Sediment collection
A 200-kg sample of inorganic sediment was collected from a Highet Creek
placer mine site on August 10,1982.This sample was coarse-screened on-site from
a seam of near-bedrock material being actively sluiced,and particle sizes <2 mm
retained.The nature of this sediment was characteristic of that commonly
referred to by placer miners as "paydirt"(Emond 1982).The sample was
transported to Vancouver in new 20-L sealed plastic buckets,whereupon it was
mixed thoroughly (240-L plastic barrel),returned to the buckets and stored at 4 0 C
until required for bioassay tests.
A sample of organically-rich overburden material weighing approximately 200
kg was obtained during August from a site alongside Minto Creek where the
vegetation had recently been stripped away.This dark-brown "muck"(80%moisture
content)was also transported to the Vancouver laboratory in new (sealed)20-L
plastic pails.The sample was mixed in a 240-L plastic barrel,returned to pails
and stored in the dark at 4°C until required for testing.
Sediment preparation and analyses
Preliminary examination of the inorganic paydirt material indicated that the
majority (>98%)of this sample was comprised of particles >1.0 mm (i.e.too coarse
for the present study).Accordingly,a procedure was derived which reduced the
sample to sediment fines.Quantities of paydirt required for each bioassay test
were oven-dried (SOoC)to constant weight.Measured amounts (200 ml =280 g)were
then pulverized for exactly 2 min using a vibratory ring pulverizer (TMS
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Engineering,Vancouver).A1iquots of pulverized paydirt were canbined and stored L.
in polyethylene bags until used.
Portions of each of these two prepared sediment types were analysed for the
following characteristics:particle size distribution;particle shape;moisture
content;volatile and fixed residue;rate of oxygen uptake;and major and trace
inorganic components.
Preliminary tests with the organic muck indicated that wet
screening of this material to select particle fines was
impractical.Quantities required for each bioassay test
coarse-screened only to remove rootlets and woody debris from
This pre-sorted undried organic overburden material was held in
beakers until used for the bioassay tests.
sieving or fine
diHicu1 t and
were therefore
the humic soil.
covered plastic
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Two 280-g samples of paydirt (sub-samples of portions prepared for the 4-day
survival tests and stress bioassays)were examined for particle size
distribution.Each sample was wet-sieved,oven-dried (SOoC)and mechanically
agitated for 10 min through a standard series of Tyler sieves.Percentage weight
of paydirt retained on each sieve was calculated (Anon.1972).
A 300-g portion of coarse-screened organic muck was wet-sieved in SO-g
increments.The oversized (+400 mesh)material retained was then oven-dried (SOO
C)and rolled out with a stainless steel rolling pin (to break conglomerates).
The resulting material was mechanically agitated (10 min)through sieves,and
calculations made of the percentage weight retained on each.
The appearance of each sediment type was examined microscopically.Both dry
and wet (suspensions in water)preparations were viewed under dissecting (SOX)and
compound (400X)microscopes.
Moisture content of each test material was determined by drying SOO-g
portions at lOS o c to constant weight.Their volatile and fixed components were
ascertained by igniting each sample at SSOoC to constant weight (Anon.1980a).
The oxygen uptake rate at lS o C for each sediment type was measured according
to a procedure used previously (Anon.1979b)for evaluating dredged sediments.
Fixed volumes (30 ml)of material were added to SOO-m1 Erlenmeyer flasks
containing SOO m1 of oxygen-saturated freshwater (Vancouver City dechlorinated tap
water)at lS o C.Each flask was stoppered,shaken and allowed to remain
undisturbed for 24 h at this temperature.Initial and final dissolved oxygen
values for the overlying water were measured (Delta Scientific Model 1010 portable
oxygen analyser with mechanical agitator)and oxygen uptake rates calculated.
The major and trace inorganic constituents of each test .material were
determined by plasma spec trographic analysis.Dried (lOSOC)preparations were
digested using a combination of acids (HF,HC1,HN03'HC104)and the resul ting
solutions analysed for metals using an inductively coupled argon plasma
spectrograph (Can Test Ltd.,Vancouver,B.C.).
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The_interrelationship of nonfiltrable residue (suspended solids),total
residue and turbidity values for suspensions of each sediment type in freshwater
was examined.A range of concentrations (nominally 0-50,000 mg sediment:L-1,dry
weight basis)of paydirt or overburden material in freshwater (Vancouver City
dechlorinated tap water)was prepared using separate 1-L plastic bottles.
Aliquots (l00-m1 volume)were taken from each bottle for determinations of total
nonfi1trable residue,total residue,and turbidity (formazin turbidity units -
FTU).Each aliquot was taken immediately after vigorous agitation of the sample
bottle.Aliquots for turbidity analyses were re-agitated just prior to
examination.All analyses were performed according to Standard Methods (Anon.
1980a).
Recycle test tanks
Thirty 50-L capacity recycle test tanks were constructed for use in the acute
survival bioassays,temperature tolerance tests and stress bioassays.The basic
design for each tank was according to Noggle (1978).The body of each tank,made
of 6-mm translucent plexiglass sheeting (transparent sheets sand-blasted to reduce
visual disturbances to fish in clear solutions),measured 41 X 37 X 36 cm.A
steeply sloping conical-shaped bottom ensured that all settleable solids would be
collected and re-circulated.During operation,the test suspension in each tank
was withdrawn continuously from this cone through a pump (Little Giant Model 1-42)
at a rate of 10.3 +0.3 Lomin-l (mean +SD;n =20),and respilled onto the
surface of the suspension (see Fig.1).-
A rectangular fish basket,made of soft-mesh nylon netting framed with
stainless steel rods,was constructed to fit the body of each tank.These baskets
were used to contain fish and to raise them for periodic observations or for
sampling.
Bioassays using these tanks were conducted in a temperature-controlled room
removed from general laboratory disturbances.Overhead incandescent lighting,
regulated by photocell,provided a natural photoperiod for all tests.Lights were
brightened/dimmed gradually OO-min automated rheostat)at the start and end of
each daily cycle to simulate natural conditions.
Acute survival tests
Fish acclimated to l5 0 C
A study was conducted to determine fish mortalities and gill histopathologies
associated with acute (up to 4-day)exposure to suspensions of paydirt or
overburden sediment fines.Five underyearling grayling acclimated to laboratory
water at 15 0 C for 7 weeks were placed randomly in each of a series of 50-L volumes
of these suspensions within the recycle test tanks.Nominal strengths (dry weight
basis)of paydirt to which these groups were exposed ranged from 50 to 250,000 mg
sedimentoL-l,and from 50 to 50,000 mgoL-1 for the overburden suspensions.Each
suspension was prepared by mixing a pre-weighed amount of test material into the
tank while the freshwater was re-circulated.Vancouver City dechlorinated tap
water (at l5 0 C)was used for preparing all suspensions and as the control water
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(no sediment added).Overhead airconditioning was regulated to hold the
temperature of each suspension within values to which these fish were acclimated.
Initial tests with the suspensions of overburden indicated that nominal
strengths 10,000 or higher (dry weight basis)fouled the pumps.Consequently,
agitation of these higher organic sediment strengths was maintained by upwelling
compressed air through the apex of the conical bottom of each of these test
vessels.
Water temperature,pH,dissolved oxygen content (mg O2 ~L -1)and conductance
(umho·cm-1 )values for each suspension were monitored daily throughout a 96-h test
period,together with fish survival and behavioural observations (surfacing,
coughing,swimming activity).Upon completion of this period of exposure,
surviving fish in each test suspension were netted sequentially and their fork
length (cm)and wet weight (g)determined.The caudal peduncle of each fish was
severed,and blood collected in heparinized microhematocrit glass capillary
tubes.All blood samples from each group of fish were collected within 5 min.
Blood samples were centrifuged (12,500 rpm;3 min)and hematocrit values (Fig.2)
measured.Plasma portions were separated and stored frozen (-20 0 C)until analysed
(10 uL aliquots)for glucose content (Beckman Glucose Analyser 2).
Gill tissue was dissected from each fish and placed immediately in Bouin's
fixative.These tissues were transferred 24 h thereafter to 95%ethyl alcohol.
Subsequently,selec t groups of these tissues (gills from three fish held in 01100,1,000,10,000,and 100,000 mg·L-1 paydirt or 0,100,5,000 and 50,000 mg·L-
overburden)were paraffin-embedded,sectioned (6 um)and stained (hematoxylin/
eosin)for histopathological examination.
A 100-ml aliquot of each test suspension was taken from the end of the pump
outlet tube (paydirt suspension)or from the centre of the tank (overburden
suspensions)at the termination of the 4-day fish survival tests.These aliquots
were dried and analysed for total residue content (Anon.1980a).Results were
expressed as final suspended residue concentration (mg sediment·L-1).
Upon completion of the 4-day exposure tests .with grayling and paydirt
suspensions,ten hatchery-reared rainbow trout (Salmo gairdneri)swimup fry (0.5 +
0.1 g;3.4 +0.3 cm)were added to each test suspension within the recycle test
tanks.These fish were acclimated to Vancouver City dechlorinated tap water since
their receipt as eyed eggs.The survival of these salmonid fish was monitored
daily throughout a subsequent 4-day period of exposure.
Exposure of one group of Arc tic grayling to a high strength of suspended
paydirt fines (50,000 mg·L-1)was continued for a total of 16 days,during which
time daily observations of fish were made.This suspension was recycled
continuously throughout the 16-day test period,and water temperature was held at
150 +1 0 C.
A final group of five grayl ing accl imated to 15 0 C was examined for 4-day
survival in a high (100,000 mg·L-1)concentration of suspended paydirt prepared by
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sieving only (no pre-grinding).Sediment used for this test was that portion of
dried material which passed through an O.S rom pore sieve.A sample of this sieved
test material was analysed for partic Ie size distribution.
Fish acclimated to SoC
The acute tolerance of SOC-acclimated Arctic grayling to suspended paydirt
fines was examined under controlled laboratory conditions.Groups of ten fish
held previously at SO +10c for seven weeks were transferred from the outside
holding tanks to separate recycle test tanks containing SO L of inorganic
suspensions ranging in concentration from SOO to 100,000 mg"L-l.Fish survival,
water temperature,pH,conductance and dissolved oxygen content in each tank were
monitored daily throughout a 4-day period of exposure.Overhead airconditioning
was adjusted to maintain the water temperature in each test tank within the range
to which these fish were acclimated (SO +O.SOC).Other conditions and procedures
were according to those described previously.
Following a 96-h exposure,individual fish surv1v1ng in each test suspension
were netted rapidly (within a 7-min period).Lengths and weights were recorded,
and blood samples collected and processed (as described previously)for
hematocrit,leucocrit (see Fig.2)and plasma glucose determinations.'
The consistency with which differing strengths of inorganic sediment remained
suspended within the recycle test tanks was examined during this 4-day test.
Aliquots (100 ml)of each suspension were withdrawn from the centre of each tank
for total residue analyses at each of the following times after their
introduction:0,O.S,S,24,48,72 and 96 h.Additional aliquots were taken
from each tank at 48 h in order to assess the dispersal pattern for each
recirculating suspension.These samples were taken from each tank at the
following locations:inflowing suspension (end of pump outlet tube);surface
(centre of tank);mid-depth (centre of tank);and near a bottom corner of the net
enclosure.Each aliquot was analysed for total residue concentration (Anon.
1980a)•
Temperature tolerance tests
Fish acclimated to lS o C
The effect of suspended.paydirt or overburden material on the critical
thermal maxima (upper lethal temperature tolerance)for underyearling Arctic
grayling acclimated to lS oC (for 9 weeks)was determined in separate studies.
Basic test procedures for this bioassay were according to those described
previously (McLeay and Howard 1977;McLeay and Gordon 1980).
Ten grayling were transferred randooly to each SO-L test suspension within
each of a series of recycle test tanks.Test apparatus and procedures for
preparing each suspension were identical to those given for the acute survival
tests.Nominal concentrations of inorganic paydirt to which fish were exposed
ranged from 2S to 100,000 mg"L-1 ,and from SO to SO,OOO mg"L-1 for the organic
overburden.
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The temperature of each test suspension was initially lS o C.This temperature
was increased progressively at a controlled rate of 1 0 coh-1 (electric baseboard
heaters coupled with a thermostatically-controlled immersion heater in each tank)
until all fish in each tank were dead.The temperature of each test suspension
was recorded (+O.lOC)at the time of death of each fish.These fish were removed
and measured (length,weight).Aliquots of each suspension were then taken from
the centre of each test vessel for analyses of final suspended residue content.
Fish acclimated to SoC
The effect of paydirt suspensions on the critical thermal maxima for grayling
acclimated to SoC for 9 weeks was examined.Groups of ten fish were transferred
from a rearing tank to recycle test tanks containing nominal paydirt suspensions
ranging from 100 to 50,000 mg °L -1.,The temperature of each test suspens ion was
initially SoC,and was increased at 10 Coh-1 until all fish were dead.Other test
procedures and conditions were identical)to those used for the temperature
tolerance tests conducted with lS o C-acclimated grayling.
Sealed jarbioassays
Fish acclimated to lS oC
Sealed jar (residual oxygen)bioassays were conducted with juvenile grayling
acclimated to lS o C for 12 weeks.Basic test procedures were those developed for
use with kraft pulpmill effluents (McLeay 1976;Gordon and McLeay 1977)and
applied subsequently with other aquatic contaminants (McLeay and Gordon 1980).
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Each jar was inverted at 20-to 30-min intervals throughout the test period
in order to re-expose fish to any settleable solids.Control jars (freshwater
only)were treated accordingly.The survival or death of fish was determined on
these (and more frequent)occasions.Upon the death of each fish,water
temperature and time to death were recorded.The residual oxygen level in each
suspension was measured using a portable oxygen meter (Delta Scientific Model No.
1010)with mechanical agitator.
For each concentration of paydirt or overburden examined,ten replicate jars
were prepared (identical weights of sediment added to each).Two replicate sets
of ten control solutions (freshwater only)were included with each series of
sealed jar tests conducted with paydirt or overburden sediments.Air-saturated
freshwater (Vancouver City dechlorinated drinking water)at 20 0 C was added to each
jar and the fish introduced.Each jar was then filled completely with water,and
sealed (plastic lid)to exclude air.
Grayling weighing approximately 10 g were selected for these bioassays.
sealed jar tests were conducted at 20 0 C using 1.9-L glass jars,one fish per
(fish-loading density,S goL-l)(McLeay 1976).
The
jar [
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The initial (maximum)and final (minimum)suspended residue concentrations to
which fish were exposed during these tests were determined.-At the time of the
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- 9 -
bioassays,one additional jar conta1n1ng each test suspension was prepared,and a
10-g fish added.Upon the inversion of each jar,an aliquot of each suspension
was extracted (by syringe)from the jar's centre.This procedure was repeated
after the jar was left undisturbed for 30 min.Each aliquot was analysed for
total residue concentration.
Fish acclimated to SoC
Underyearling grayling acclimated to SoC freshwater for 11 weeks and weighing
approximately 10 g were selected for this study.Sealed jar bioassays with
differing strengths (100-100,000 mg-L-l)of suspended paydirt fines were conducted
at 10o C,using air-saturated freshwater adjusted to this temperature overnight as
the control or test (dilution)water to which fish were exposed.Otherwise,test
apparatus and procedures used for this bioassay were identical to those employed
in the previous sealed jar test with grayling and paydirt.
Acute stress bioassays
Controlled bioassays were performed to determine the concentrations of
paydirt and overburden suspensions which are acutely stressful to Arctic
grayling.Basic test procedures were those proven effective for determining
threshold strengths of a variety of aquatic contaminants which cause stress
responses (elevated blood sugar levels,decreased numbers of circulating
leucocytes)with other salmonid fish species (McLeay 1977;McLeay and Gordon 1977,
1979,1980).
Groups of ten underyearling grayling acclimated to lS o C for 12 (overburden
bioassays)or 13 weeks (paydirt bioassays)were transferred from the outside tanks
to a series of indoor recycle tanks containing freshwater (at lS 0 C)only.Fish
were left undisturbed in these tanks for a 48-h period in order to adapt to the
stress caused by this transfer.Thereafter,weighed portions of paydirt or
overburden sediment were added to each tank at 20-min intervals.Tanks for each
treatment were chosen randomly.For each test (paydirt or overburden material),
two tanks were selected as controls.Nominal concentrations of paydirt to which
these fish were exposed ranged from SO to 100,000 mg'L-1,and from SO to 20,000
mg-L-l for fish held in suspensions of overburden material.
Each group of ten grayling was sacrificed for blood sugar and leucocrit
determinations after a 24-h exposure to each sediment suspension.The control
groups were sampled just prior to and again just subsequent to the sampling of all
experimental g'roups to ensure that no changes in the stress responses measured
were caused by sampling disturbance.Sampling procedures and methods for
determining plasma glucose,hematocrit and leucocrit values for each fish were
identical to those described previously in this report.
-10 -
Reference toxicant tests
The response of the laboratory-reared Arctic grayling to the reference
toxicant pentachlorophenol (Davis and Hoos 1975)was determined at the time that
these bioassay tests were conducted.Fresh stock solutions of pentachlorophenol
were prepared by dissolving 100 mg dry powder (Aldrich Chem.Co.Inc.;Lot No.
122047;purity >99%)in 10 ml of 2%NaOH,and diluting to 1 L with deionized water
(Alderdice 1963).These concentrated stock solutions were diluted ten-fold as
required for each bioassay.
The acute lethal tolerance to pentachlorophenol of grayling acclimated to ISO
or SoC was determined just prior to the start of the acute survival tests with
paydirt sediment.Groups of ten fish were transferred from stock tanks to 4S-L
glass aquaria containing pentachlorophenol concentrations (diluted with Vancouver
City dechlorinated tap water)ranging from 30 to 120 ugoL-l.Test temperature tcii:·
these static bioassays was held at that to which the grayling were acclimated (ISO
or SOC).Fish survival in each test solution was monitored daily throughout a
4-day test period.
The effect of sublethal and lethal concentrations of pentachlorophenol on the
upper lethal temperature tolerance of juvenile grayling acclimated to lSoC was
ascertained.Groups of ten fish were trans ferred from a stock tank to recycle
test tanks containing pentachlorophenol strengths of 0 (freshwater control),2S,
SO and 80 ugoL-l freshwater.The temperature of each test solution was increased
from an initial value of lSoc at a rate of 10coh-l until all fish died,and the
temperature at time of death of each fish determined.Conditions and procedures
for conducting this bioassay were identical to those described for the temperature
tolerance tests performed with lSoC-acclimated grayling and sediment suspensions.
The effect of pentachlorophenol on the tolerance to hypoxia of lSoC-
acclimated grayling was determined by sealed jar bioassay.Materials and methods
were those described earlier.Residual oxygen levels at death were determined for
fish held in jars containing pentachlorophenol strengths of 0 (two freshwater
control groups),3S,SO and 80 ugoL-l •
The effect of sublethal concentrations of pentachlorophenol on acute stress
responses for lSoC-acclimated grayling was examined at the time and according to
procedures described for the stress bioassays carried out with grayling and
sediment suspensions.For these tests,four groups of ten fish were exposed to
the following strengths of this reference toxicant for 24 h:0 (freshwater
control),20,3S and SO ugoL-l.Plasma glucose,hematocrit and leucocrit values
for each of these fish were measured as described previously.
The length (cm)and wet weight (g)of each fish exposed to pentachlorophenol
were determined at time of death or upon termination of each bioassay test.
Statistical analyses
The condition factor (K)of juvenile grayling used in each bioassay test
was determined as follows:K =cW·L-3 where c is a constant (l00),W is
weight (g)and L represents fork length (cm)(Carlander 1969)0
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-11 -
Mean and standard deviation (SD)values for fish length,weight and condition
factor were calculated for each bioassay.Mean +SD plasma glucose,hematocrit and
leucocrit values determined for each group of fish receiving identical treatment
were also determined.Additionally,mean (+SD)temperatures at death
(temperature tolerance and sealed jar tests),times to death and residual 02
values at death (sealed jar test)were calculated for each control and test
group.For values shown graphically,the 95%confidence interval of each mean
was determined.
The median effective concentration (EC50 value)of each sediment type causing
a net significant response for 50%of the fish treated identically in each
bioassay (temperature tolerance test,sealed jar and acute stress bioassays)was
calculated according to established procedures (Sprague 1968;McLeay and Howard
1977;McLeay and Gordon 1980).Relevant values determined for each test fish
(i.e.temperature at death,temperature tolerance test;time to death and residual
02 at death,sealed jar bioassay;plasma glucose and leucocrit,acute stress test)
were examined to determine the number of responses for each treatment outside of
the 95%confidence interval for the corresponding group(s)of control fish.
Depending on the suitability of the data derived in this manner the EC50 value for
each test was calculated,together with its 95%confidence interval (Stephan
1977).
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The acute median lethal concentration
toxicant pentachlorophenol,as determined
acclimated to 50 or 150 C,W'as calculated
interval)using the computerized LC50 program
(96-h LC50 value)for the reference
with groups of juvenile grayling
(together with its 95%confidence
of Stephan (1977).
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FIELD STUDIES
Study area
General
The Highet Creek and Minto Creek sites chosen for the in-situ caged fish
bioassays were selected following an aerial and ground reconnaissan;e-of some nine
creeks in Central Yukon on June 26 and 27,1982.The study area (Fig.3)lies in
the Selwyn Basin portion of the Canadian Cordillera,and is underlain by
sedimentary limestone skarn and quartzite schist rocks of the Windermere Group
(Tipper et al.1982).Quartz is the main mineral in this mineralogically complex
rock,although diorite and granitic rock protrudes through the older schists in
several areas.
The surficial deposits in the area can be divided into three recognizable
types:the upper,post-glacial unit consisting of recent and terrace gravels;the
glacial unit consisting of till or glacio-lacustrine silts and sands;and the
lowermost pre-glacial unit making up the deep,terrace and high level gravels.
Several of these deposits,in particular the deep gravels,glacio-lacustrine silts
and sands and the till,are exposed in Highet Creek (Cairnes 1915).
-12 -
The pre-glacial deep and terrace gravels are the most productive in terms of
placer gold.They cover the hummocky bedrock of the valley bottom and are from 3
to 8 metres thick.The lower 2-4 m of the deep gravels are commonly stained with
manganese oxide and iron oxide.The black to red oxides occur in the gravel
matrix and as a stain on the clast surfaces.Some manganese oxides occur in
crystals (Emond 1982).
Glacio-lacustrine silts and sand gravels varying in thickness from 3 to 25 m
overlie the pre-glacial gravels.These sediments are usually finely laminated
dark grey sil t layers interlaid with brown sand.The silts were deposited in a
shallow lake that was formed when ice,moving westward up Minto Creek,protruded
into the lower part of Highet Creek (Bostock 1939).
The glacial till of Highet Creek varies in thickness from 1 to 4 metres.The
gravel contains pebbles of assorted rock types.The matrix is a yellowish brown,
silty or gritty clay (Emond 1982).Recent gravels approximately 2 metres thick
are found in the lower part of the creek valley.The gravel contains well-rounded
pebbles and cobbles that are less than 7 cm in diameter.Trace geochemical
analyses indicate that gold,tungsten,chromium,iron,manganese,titanium,zinc
and zirconium are the most abundant heavy elements in the Highet Creek gravels.
Tin,arsenic,cadmium,and mercury were not detected (Emond 1982).
In the Mayo-McQuesten area,gold was first found on sand bars of the Stewart
River in 1883.Prospecting of creeks draining the upland led to the discovery of
gold,in 1901,in Duncan Creek.Gold was first discovered on Highet Creek in 1900
by Warren Hiatt.Mining began in 1903 on bench claims on the right limit of the
upper part of the creek.Several operators mined gravels in the creek bottom
during the period 1916-1946.During this early period,a dredge was worked
unsuccessfully on the creek for one season.Since 1960,mining on Highet Creek
has consisted of three small individual operations which utilize earth-moving
equipment and large sluice boxes.Highet Creek has been one of the leading gold
producing creeks in the Mayo-McQuesten area.
Highet Creek
Highet Creek originates on the upland (maximum elevation 1825 m)between the
McQuesten and Stewart rivers,and flows to the southwest through a narrow valley
into Minto Creek (Fig.3).Although ungauged,this high gradient stream
(elevation change 90 m-km-l )likely exhibits a seasonal hydrograph similar to
other small creeks subject to placer mining in the Mayo area.In undisturbed
creeks,peak flows occur during May and early June in response to snowmelt (Anon.
1980b).However,during the summer months the flows in Highet Creek are
regulated,and hence may vary considerably from day to day in response to placer
mining activity.Winter freeze-up of this creek usually begins in November and
extends to April (Allen and Cudbird 1971).
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During the open water period,Highet Creek is frequently turbid
mining and erosion of previously mined sections of the valley.
suspended sediment load carried by the creek from June to October
due to placer
Most of the
is created by
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-13 -
mining operations 1n the upper third of the valley.In the lower sections of the
creek,the suspended sediment load consists of that portion of the mine effluent
remaining after passage through several settling ponds located 3.0 km upstream of
Minto Creek (Fig.3).
No information on the former use of Highet Creek by fish is available.A
preliminary species abundance/habitat study conducted during the summer of 1982
found only limited numbers of underyearling Arctic grayling within Highet Creek,
whereas Minto Creek and other Minto Creek tributaries (Bennett Creek,Mud Creek)
contained appreciably larger populations of Arctic grayling and other species of
fish (Birtwell et al.1983).
The site in Highet Creek selected for in-situ caged fish studies was located
0.25 km upstream of the junction with Minto Creek (Fig.3).Biophysical
characteristics determined for this site during these field bioassays are provided
in Appendix 1.
Minto Creek
Minto Creek flows eastward into the Mayo River through an upland part of the
Yukon Plateau that lies between the Stewart and McQuesten river valleys (Fig.3).
Minto Creek originates at Minto Lake (elevation 685 m)and follows a winding l6-km
course into Wareham Lake (elevation 580 m).The stream gradient is generally low
(l.5 m'km-l ),particularly in the upper third where it is further reduced by a
series of beaver dams.Although ungauged,Minto Creek likely exhibits a seasonal
hydrO-graph similar to other lake-fed streams in the Mayo area.Peak flows occur
shortly after breakup in late Mayor early June whereas low flow usually occurs in
February or March (Anon.1980b).The valley of Minto Creek is undisturbed with
the 'exception of a site approximately 1.5 km below Minto Lake that was placer
mined briefly in 1980.
During the summer months,water in Minto Creek above its confluence with
Highet Creek is clear to slightly turbid.Below Highet Creek,Minto Creek water
is frequently turbid from June to October each year due to the placer mining
activities on Highet Creek.
The control site in Minto Creek selected for the in--situ caged fish studies
was 0.5 km ups team of the junction with Highet Creek-,-ata location that was
'similar in stream flow and other characteristics,except suspended solids,to the
test site in Highet Creek (Appendix 1).This site was chosen for its clear water
and its proximity to the Highet Creek site.
Fish collection
For the in-situ caged fish studies,several hundred wild underyearling Arctic
grayl ing wer;captured from Minto Creek for August bioassays,or from both Mud
Creek (Fig.3)and Minto Creek for September bioassays.Those fish taken from
Minto Creek were collected 0.5-0.8 km upstream of the junction with Highet Creek.
-14 -
Fish were captured from shallow pools and riffles,using one or more seine
nets.Upon netting,fish were placed in plastic holding pens lined with
fibreglass screening (allowing free flow of creekwater).All captured fish of
suitable size were held for 1 to 2 days in Minto Creek (just upstream of the
control site)prior to their transfer to cages.
In-situ bioassays
Test apparatus
Ten net enclosures were used for the in-!ltu bioassays.Each enclosure (30
cm deep by 45 cm diameter)consisted of two aluminum rings covered with soft nylon
mesh (4 mm).A drawstring in the mesh at the top of the enclosure could be opened
to inspect the fish (Fig.4).
At each site (Fig.5 and 6),five enclosures were located adjacent to one
another at the upstream end of a pool.Each 50-L enclosure was suspended in the
water column,5 to 10 cm below the surface,between three tubular iron posts
(Fig.4).The position of the posts provided stability and allowed each enclosure
to be lifted independently for inspection,while at the same time ensuring free
circulation of water.
Water quality
Water samples were collected at both the test site (Highet Creek)and the
control site (Minto Creek)during the August and September caged fish tests.
Samples (300-400 ml)were collected hourly at each site for the duration of the
tests,using an ISCO automatic pump sampler.The sampler's intake port was
located wi thin an empty fish cage submerged at each site.Samples were removed
every 24 h and stored in plastic bot tles within coolers for shipment to the
Environmental Protection Servic'e/Fisheries and Oceans laboratory at West
Vancouver.The following characteristics were measured for alternate samples
collected from each site,using procedures established by Environment Canada and
Fisheries and Oceans (Anon.1979c):total residue;total fixed residue;
nonfiltrable residue;total volatile residue;and turbidity (FTU).
The particle size of nonfiltrable residue within Highet Creek was estimated
from composite creekwater samples taken during both the August and September test
periods.These samples were made by combining one hourly water sample selected at
random from each of the test days.Each composite sample was analysed by Soil
Analysis Inc.(Vancouver)for particle size distribution,using the pipet method
(Anon.1975).
On seven occasions during the August and September test per iods,duplicate
grab samples were taken from Highet Creek adjacent to the test enclosures.These
samples were collected to coincide with samples being drawn from within the
enclosures by the automatic sampler.Analyses included turbidity (FTU),
nonfiltrable residue and total residue.
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-15 -
Two or more times daily during each in-situ bioassay,the following variables
were measured near the net enclosures at each site:water temperature (oC),pH,_
and dissolved oxygen (mg 02°L-l).Water temperature was measured using a mercury
thermometer.A portable YSI Model 57 dissolved oxygen·meter and a Corning Model
6l0A pH meter were used for the other field determinations.
Several 150-or 250-ml water samples were collected in polyethylene bottles
at the enclosure sites.Samples were collected at the beginning and end of each
test period for alkalinity,hardness,Mn,Mg,Na,Ca,Si,and total metals (As,B,
Ba,Cd,Cr,Cu,Hg,Ni,Pb,Sb,Sr,Zn,AI,and Fe)•Samples not requiring
preservation were kept cool for return to the laboratory at the conclusion of each
study period.All metals except Hg were preserved with 1 ml of HN03;Hg samples
were preserved using a solution of H2S04 and K2Cr207'Analysis of all water
samples was performed at the Environmental Protection Service/Fisheries and
Oceans'West Vancouver Laboratory,using techniques specified (Anon.1979c).
Experimental
Short-term (4-to 5-day)in-situ bioassays were conducted at the Highet and
Minto Creek sites on each of two ~sions -August 6 to 10,and September 10 to
15.These field bioassays were conducted twice to determine the effect,if any,
of different water temperature regimes on the acute tolerance of grayling to
suspended sediment.
In orde r to ma intain a load ing dens i ty of approxima te ly 1 go L-1,groups of 14
to 26 fish were selected randomly from the holding pens on each occasion,and
transported in plastic pails to each of four net enclosures at each site.The
mean density of fish placed in each enclosure was approximately 1 gOL-I •During
August,each cage received grayling captured from Minto Creek;whereas during the
September tests,fish introduced to only two of the four cages at each site were
captured from Minto Creek.The remaining two cages at each site on this occasion
received Mud Creek fish only.
Fish within each cage were observed hourly for the initial 4-h period,and
twice daily (between 0900 and 1100 h,and between 1900 and 2200 h)thereafter
until the tests were terminated.Each inspection was carried out by raising the
cage until its bottom was just below the surface of the water.Inspections were
conducted quickly to minimize stress to fish.Any dead fish observed were removed
and examined (including measurements of length and weight).Times to death and
frequency (%)of fish mortalities were recorded.Fish in cages were not fed on
either occasion.
Upon completion of a 96-h (August bioassays)or l20-h (September bioassays)
period of exposure,all surviving fish in each cage were sacrificed.Fish were
removed individually from each cage,and their fork length and wet weight
determined.Gill arches (third or fourth)were removed from five fish selected
randomly from each net enclosure,and mounted on glass slides in polyvinyl
lactophenol.These tissues were later examined under dissecting and compound
microscopes to detect any gross changes in gill morphology.
-16 -
For the September bioassays only,gill tissues of five grayl ing caged in
Minto or Highet Creek for five days were removed and placed in Bouin's fixative.
Gills from five untested grayling seined from Minto Creek were also taken and
preserved upon fish capture.These 15 tissues were subsequently transferred to
70%ethyl alcohol,wax-embedded,sectioned (6 um)and stained (hematoxylin and
eosin)according to standard practice.For each specimen,a number of
pathomorphological changes involving the gill filaments and lamellae were rated on
a scale of 0 (normal)to 4+(extreme pathology).Each specimen was coded and
examined "blind"(without knowledge of treatment)to prevent biases from
influencing the ratings assigned.
Blood samples were taken from five fish selected randomly from each cage at
the time of these autopsies.Each sample,collected in a heparinized
microhematocrit tube,was centrifuged in the field (microhema tocrit centrifuge
with 12-V battery and power converter),and hematocrit values determined.Plasma
portions were separated and stored cool but unfrozen (held on ice)for subsequent
glucose analyses.Other procedures for blood collection and analyses were
according to those described previously.
Samples of blood were taken from 19 and 30 underyearling grayling captured
by seining from Mud Creek (August 9,1982)and Minto Creek (September 14,1982),
respectively.These samples were taken within 5 min of fish capture.Blood
hematocrit and glucose values were determined for each of these fish according to
procedures used for caged fish.
RESULTS AND DISCUSSION
LABORATORY STUDIES
Fish growth and condition
All grayling air-expressed to Vancouver were alive and in apparently good
condition upon their receipt.Efforts to initiate feeding of those fish received
as swimup fry proved largely unsuccessful,resulting in a high rate of mortality.
These fish mouthed the Biodiet ration offered,but spit it out.Offerings of
other ration types (i.e.live Daphnia pulex or finely-ground beef heart)were also
unaccepted by these very small fish.Unlike these findings,the larger fish
(0.2-1.0 g)commenced active feeding within one week of their receipt.Biodiet
ration no.1 was consumed vigorously by these fish and mortality rates were low.
Cannibalism of smaller grayling was observed frequently,although size-
sorting of surviving fish between the four outdoor rearing tanks appeard to mini-
mize this problem.Fish transferred to these tanks fed actively on the commercial
rations offered (Biodiet and,later,OMP).Live brine shrimp was readily taken by
the fish.Growth of fish acclimated to the 15°C laboratory water supply (pH 6.8 *
0.2;conductance,15.7 ±1.2 umbo·cm-l ;nonfiltrable residue,<0.1 mg·L-l;
residual chlorine,<0.01 mg·L-l;alkalinity,4.5 ±1.3 mg CaC03·L-l;EDTA
hardness,5.0 ±0.3 mg CaC03·L-1)was rapid,with mean (*sD)weights of 2.4 ±
1.2 g by 6 weeks.The stock tank of larger grayling (sized-selected for the
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-17 -
sealed jar bioassays)weighed 10.4 +1.3 g at 12 weeks.Mean condition factors
determined for groups of lS o C-acclimated grayling sampled from the rearing tanks
for bioassay tests were 0.8 to 1.0.These values are typieal of those determined
for underyearling grayling collected from the Minto Creek drainage (Birtwell et
ale 1983).
Upon lowering of the water temperature to SoC,the rema1n1ng stock supply of
grayling (divided between three outdoor tanks)ceased to feed.Offerings of OMp
and brine shrimp were largely rejected during the subsequent S-week period.
Thereafter,an attempt to promote feeding by introducing freshly thawed sockeye
salmon eggs proved successful.Active feeding resumed at this time and continued
until the bioassay tests with SOC-acclimated fish were terminated.Condition
factors for grayling at the time of these bioassays were similar to previous
values (0.8-0.9).The quality of the SoC water to which these fish were
acclimated was as follows (based on weekly measurements):pH 6.7 +0.2;
conductance,14.3 +2.2 umhoocm-1 ;nonfiltrable residue,<0.1 mg~L-1;residual
chlorine,<0.01 mfoL-1;alkalinity,S.3 ~0.8 mg CaC0 3 °L-1;and EDTA hardness,6.2
~1.2 mg CaC03°L-•
No behavioural anomalies nor signs of disease were evident within the stock
supply of grayling held at ISo or SoC for the laboratory tests.All fish deaths
observed (other than those due to cannibalism)were attributed to starvation.
lethal tolerance (96-h LCSO;9S%confidence interval in
the reference toxicant pentachlorophenol determined for the
grayling acclimated to ISo or SoC was as follows:
lS o C fish:67 ugoL-1 (S7-77);
SoC fish:61 ugoL-1 (48-71).
All grayling acclimated to either temperature regime survived a 96-h exposure to
pentachlorophenol strengths of 40 ugoL-l and lower.These LCSO values are within
the range of tolerance for this respiratory inhibitor reported previously for
populations of healthy hatchery-reared rainbow trout or coho salmon (Oncorhynchus
kisutch)fingerlings acclimated to and tested in 10-120 c water with pH and
hardness characteristics similar to that used in the present studies (Davis and
Hoos 1975;McLeay and Gordon 1980).Results from these bioassays,considered
together with the observations of the fish stocks,suggest that the condition and
tolerance to aquatic contaminants of the laboratory-reared grayling were typical
of healthy populations of young salmonid fish species at the time that each series
of bioassay tests with suspended sediments was undertaken.
Various workers have reported difficulties with the artificial propagation of
grayling.Davis (1967)indicated that certain early investigators were only able
to rear grayling fry to the fingerling stage when fish were supplied with creek
water containing natural food.Others (Rawson 19S0)reported success with finely
ground beef liver or heart,supplemented with goldfish food.
As with the present study,other attempts to initiate feeding under
laboratory conditions for Arctic grayling captured in the wild as swimup fry have
proven largely unsuccessful (LaPerriere and Carlson 1973;Horler MS,1980).Part
of the problems encountered by these investigators were likely due to the type
-18 -
(and crumble size)of commercial ration offered.Transfer stress associated with
the capture and transport of swimup fry may also be implicated,together with any
prior history of their feeding in the wild.Young grayling fry are thought to be
planktivorous feeders',and their early feeding may be restricted by the relatively
large size of food organisms available (Bishop 1971;Schmidt and 0'Brien 1982).
Since the initial laboratory feeding of wild grayling captured as fry>0.2 g was
achieved in the present studies using Biodiet,this commercial ration-appears to
be adequate for this purpose.However,the use of other (non-commercial)food
supplements (i.e.live brine shrimp for lSoC-acclimated fish;sockeye salmon eggs
for SOC-acclimated fish)was also required to maintain feeding vigour.
Characteristics of test sediments
Particle size distributions for the paydirt and overburden sediments used in
the laboratory bioassays are given in Table 1.Analytical results for each of the
two preparations of paydirt fines were similar.Over 90%of the particles in each
inorganic sample examined were <0.2 mm (i.e.fine sand,silt or clay);and
approximately 70%of the test material was <O.OS mm (silt and clay).The majority
(60-6S%)of the inorganic sediment sample to which grayling were exposed was
comprised of particles less than 0.038 rom «38 um)in diameter (Table 1).Unlike
this material,approximately SO%by weight of the organic overburden was made up
of coarse material ()0.2 mm)and only 3%of this soil sample was very fine
particles (<38 um).The remainder (47%)of the overburden contained particle
sizes characteristic of fine sand or coarse silt.The particle size distribution
of these test sediments is,in general terms,characteristic of overburden
material found overlying paydirt gravel and of inorganic fines carried into
downstream waters during sluicing operations (Anon.1981).
Microscopic examination (400X)of the inorganic material indicated that the
dry tan-brown sediment formed amorphous particles (electrostatic adhesion)which
readily dissociated into minute particles upon addition to water.The dark-brown
overburden sample was comprised of a considerable quantity of woody debris
interspersed with soil particles of various shapes and sizes (very fine to
coarse).Further detail concerning the shapes of these test materials could not
be discerned by light microscopy,and scanning electron microscopy was not
applied.
Values for moisture content,volatile/fixed residue content and oxygen uptake
rate (in freshwater at lS o C)for each test sediment are presented in Table 2.
The moisture content for the overburden muck remained at 82-8S%throughout the
period that this sample was stored.This sample was comprised of 96%volatile
(organic)material;whereas the volatile component of the paydirt was only 4%of
the dried residue.This difference in organic content is consistent with the
appreciably greater oxygen uptake rate determined for the overburden material
(Table 2).
The metal content of each test sediment is given in Table 3.1bese values
are presented only for sample "fingerprinting";and an analysis of metals
dissolved (and conceivably biologically available)within freshwater suspensions
of these test materials was beyond the terms of reference of this investigation.
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Thus the extent to which a high concentration of certain constituents (i.e.the
arsenic content of the paydirt sample)mayor may not contribute to any biological
effects noted for freshwater suspensions of these materials cannot be ascertained
from these data.
Figures 7 and 8 illustrate the interrelationship of total residue,
nonfiltrable residue and turbidity values for differing strengths of each sediment
type suspended in freshwater.For both the inorganic and organic sediments,total
and nonfiltrable residue values for each sample were almost identical.These
values were highly correlated with sample turbidity,and with nominal
concentrations (Fig.7 and 8).
Results from these analyses indicate that the total residue values determined
for suspensions of paydirt or overburden taken during the bioassay tests are good
approximations of their total nonfiltrable residue (suspended solids)content.
The turbidity values measured for each suspension allow rough calculations (based
on total res idue determinations)of the turbidi ties of the test sus pens ions to
which fish were exposed.
The degree to which sediment loadings remained in suspension within the
recycle test tanks,throughout a 96-h test period,is illustrated in Figure 9.
Total residue values determined for the lowest paydirt strength monitored (500
mg -L -1)varied appreciably and showed a trend to decline with respect to time
sampled;whereas respective values for the higher strengths monitored
(5,000-100,000 mg-L-1)were more consistent throughout the 96-h test period.The
total residue concentrations measured for each treatment were generally lower than
the nominal (pre-weighed)strength of sediment added to each tank (Fig.9).
Information concerning the dispersal pattern for suspended sediment within
the recycle test tanks is provided in Table 4.For each suspension examined,the
total residue value for the sample taken from the hose outlet (tank inflow)was
appreciably (2-5 times)higher than respective values for samples taken from the
surface,mid-depth or bottom locations within the net enclosures where fish were
held.For paydirt strengths >5,000 mg °L -1,total residue values for the surface
water were slightly but consistently lower than respective values for samples
taken mid-depth or from the bottom of the net enclosure (Table 4).These results
indicate that,for each of these test suspensions,a portion of the sediment fines
was settling and being recirculated.Since the gradient for suspended solids
within the portion of each tank to which fish were confined was small,and since
these fish were continuously subjected to the settleable solids,the nominal
(pre-weighed)strength of paydirt prepared in each recycle tank should approximate
that to which the fish were exposed.However,this may not be true for the lower
concentrations (i.e.<500 mgoL-l;Fig.9)tested in these tanks.In such
instances a greater proportion of the sediment fines added may adhere to the
netting or tank sides,and therefore be effectively unavailable.
-20 -
Acute survival and gill histology
All lSoC~acclimated grayling survived a 4-day exposure to each suspended
paydirt strength examined,up to and including 250,000 mgoL-1 (Table S).
Additionally,the five grayling held in 50,000 mgoL-1 for a more prolonged period
(16 days)survived this extended exposure.All hatchery-reared rainbow trout fry
introduced to these suspensions at the termination of the bioassays with grayling
also survived for 96 h.
All grayling held in a 100,000 mgoL -1 strength of the sample of paydirt
prepared by fine-sieving only (no pre-grinding of test material)survived the
4-day exposure.These fish were active and showed no overt signs of damage at
this time.Particle size analysis of the sediment to which this group of fish was
exposed indicated that 47%of the sample was coarse sand (>0.2 mm),and that only
22%of the test material was very fine particles (<38 urn).Thus,as with the
pulverized preparations of paydirt fines examined,this coarser inorganic sediment
suspension also permitted acute survival of underyearling grayling.
All graylinf acclimated to lSoC and held in organic overburden suspensions up
to SO,OOO mgoL-(nominal strength)survived the 4-day test period (Table 6).
Those fish acclimated to SoC and exposed to coldwater suspensions of inorganic
.paydirt fines up to and including 10,000 mgoL-1 also survived for four days;
whereas mortalities of 10%(20,000 mgoL-1)to 20%(100,000 mgoL-l)were found with
fish groups held in higher sediment strengths (Table 7).In these instances,fish
deaths did not occur until after a 48-h exposure.All control fish examined in
each survival test were alive and in apparently good condition throughout the 96-h
period of exposure.
Behavioural observations of fish during the acute survival tests were
restricted due to the opacity of the suspensions.For the more dilute suspensions
of paydirt or overburden permitting these observations (SO and 100 mg °L -1)'no
signs of coughing or increased swimming activity were seen.
In both the SoC and lSoC bioassays with paydirt,grayling held in sediment
strengths >10,000 mgoL-1 remained at the surface of each suspension.These fish
showed no-signs of respiratory distress.In exhi~iting this behavioural
abnormality,the fish could have been detecting and;tseeking lower sediment
strengths within the surficial waters (Table 4).Surfacing of fish was not
apparent in the lower strengths of paydirt examined nor in any concentration of
suspended overburden.
Inspection of fish at time of autopsy indicated no overt signs of distress or
damage (i.e.lethargy,fin or snout erosion,skin lesions,exophthalmos,external
or internal bleeding).Gross examination of gills showed no increased mucous
production nor signs of damaged tissue attributable to any strengths of paydirt
(50 or lS o C tests)or overburden to which these fish were exposed for four days.
No changes in gill his tology occurred due to exposure of any grayling to
suspensions of paydirt up to and including 100,000 mgoL-l.The acute effect of
higher sediment strengths (i.e.250,000 mgoL-1)on gill morphology was not
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-21 -
examined.Similarly,the appearance of the gill tissues examined for fish held in
overburden suspensions of 0 (freshwater control)to 50,000 mg'L-1 for four days
was identical.
The structure of the gill filaments and lamellae of all tissues examined
was,in general,similar to that described as "normal"for other salmonid fish
species (Herbert and Merkens 1961;Morgan and Tovell 1969;Noggle 1978).Gill
filaments were covered by a thick stratified epithelium,whereas the secondary
lamellae consisted of leaf-life structures composed of a pillar cell system
delineating blood capillaries covered by a monolayer of flattened or sl ightly
enlarged epithelial cells.
For the gill tissues examined,no hyperplasia,clubbing or fusion of lamellae
was caused by any sediment exposures.Sediment particles were frequently observed
between adjacent gill filaments of exposed fish.The amount of sediment observed
appeared to be correlated with the concentration of suspended material to which
fish were exposed.Otherwise,the histology of gills from fish held in
suspensions of overburden or paydirt fines for four days could not be
distinguished from that of the freshwater controls.
Water quality conditions (pH,temperature,conductance,dissolved oxygen
content)to which grayling were exposed during the 4-day survival tests are
presented in Appendices 2-4.In each bioassay,the temperature of each suspension
varied by 1 0 C or less throughout the test period.The dissolved oxygen content of
each suspension was unaffected by sediment type or strength,and was maintained
above 80%saturation by the recirculating test apparatus.The pH values of each
suspension were also unaffected by sediment strength or type.For both the
paydirt and overburden materials,the higher (~1,000 mg 'L-1)concentrations of
suspensions examined caused a slight «20 umho 'cm-1 )but consistent elevation in
conductivity.This minor difference was evident within 30 min of startup of each
test,and did not change appreciably with respect to time.
To the best of our knowledge,the lethal tolerance of Arctic grayling to
suspended sediment has not been examined previously under controlled conditions.
Available information concerning the lethal tolerance of other salmonid fish
species to sediment is sparse and somewhat inconsistent.Smith (978)reported
that high concentrations (28,000-55,000 mg 'L-l)of suspensions prepared from two
natural sediment sources were required to cause mortalities of chum salmon
(Oncorhynchus keta)fry within four days.On the other hand,Herbert and Merkens
(961)reported that a 10-to 25-day exposure of juvenile rainbow trout to
suspensions of kaolin or diatomaceous earth as low as 270 mg'L-1 caused
significant mortalities of test fish.Noggle (1978)determined that the acute
lethal tolerance (96-h LC50 values)to suspensions of natural sediments for groups
of wild or hatchery-reared juvenile coho salmon,chinook salmon (0.tshawytscha)
or steelhead trout (~.gairdneri)varied from 1,200 to 35,000 mg'L-T.Differences
noted were attributed largely to seasonal temperature variations,with a lower
tolerance of fish to sediment observed during the summer months.This conclusion
was supported by a report of lower lethal concentrations of natural sediments for
non-salmonid fish species,with higher test temperatures (Rogers 1969).
-22 -
The present findings for grayling indicate that this salmonid fish speCies
can survive short-term exposure to very high concent~ations of suspended inorganic
or organic sediment under controlled laboratory conditions,despite changes in
season and temperature.The minor «20%)mortalities noted for grayling
acclimated to SoC and held in 10,000 or-100,000 mg °L -1 strengths of coldwater
(SOC)suspensions of inorganic sediment fines for four days suggest a decrease in
lethal tolerance to sediment for fish acclimated to colder water;however,
confirmation of this requires further studies.Since hatchery-reared rainbow
trout swimup fry also survived acute exposure to very high strengths of the
suspended inorganic fines to which grayling were exposed,one should not conclude
that Arctic grayling are more tolerant to suspended sediment than other salmonid
fish species.Perhaps differences in the nature of the suspended material
examined in these versus previous (Herbert and Merkens 1961;Noggle 1978;Smith
1978)tests better explain the disparities in lethal tolerance to sediment noted.
Assuming that other water quality conditions were compatible with fish survival,
it is unlikely that suspended concentrations of the overburden muck or paydirt
fines examined in these tests could be elevated sufficiently in natural streams to
cause direct mortalities of resident populations of healthy juvenile Arctic
grayling or other salmonid fish species due to short-term exposures.
A number of investigators have found histopathological changes in fish gills
attributable to sediment exposure.Herbert and Merkens (1961)observed thickening
and fusion of secondary gill lamellae of some rainbow trout exposed for several
weeks to diatomaceous earth or china clay.Noggle (1978)reported notable gill
histopathologies in certain juvellile salmonid fish held in inorganic sediment
suspensions ..s.13 ,000 mg °L -1 for ~Wto 96 h.Other researchers have also reported
thickening and fusion of gilL lamellae in trout held in suspensions of
diatomaceous earth for up to 96 h (Noggle 1978)~Unlike these findings,no gill
histopathologies attributable to short-term exposure of grayling to suspensions of
inorganic or organic sediment were noted in the present laboratory tests.
Similarly,Smith (1978)found no damage to gills of juvenile chum salmon (0.keta)
acutely exposed to high (up to 55,000 mgoL-1 )concentrations of suspended
inorganic sediment.
In his review of the effects of suspended sediment on fish,Pickral (1981)
cited the variability in findings of fish gill tissue damage caused by high
concentrations of suspended sediment,and suggested a lack of convincing evidence
for such an effect.We interpret this variability in response to differing
sediment characteristics (particle shape,size,hardness),biological (fish age,
size and prior history of exposure)and experimental (exposure period,test
apparatus)differences.More detailed examinations of gill histology for fish
held in differing types of sediment sus pens ions under controlled conditions are
required in order to understand the relevance of these variables.
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Temperature tolerance tests
Mean critical therm;l maxima (~pper lethal temperatures)for groups gf .[
grayling acclimated to 15 C water",and tested in freshwater only were 27.5-27.9 C
and variances (SD)were small (Ta~Jes 8 and 9).Mean values for fish groups held
in paydirt strengths of 500-100,000 mgoL-l were reduced slightly but consistently .[
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from control values (Table 8)and,at least for the higher sediment suspensions
examined (>S,OOO mgoL-1 ),showed a somewhat greater response to increasing
sediment strengths (Fig.10).Variances (SD,9S%confidence interval)for each
group were unaffected by treatment.The highest paydirt strengths to which
grayling were exposed (SO,OOO and 100,000 mgoL-l)reduced their mean critical
thermal maxima by only l o C.
For grayling acclimated to lS o C and 'held in various strengths of suspended
overburden,temperatures at death were somewhat more variable and did not decline
consistently from those for control fish until test concentrations exceeded a
nominal strength of 1,000 mgoL-l (Table 9,Fig.11).Mean critical thermal maxima
for groups of grayling held in overburden concentrations of S,OOO-SO,OOO mgoL-1
were decreased from the control value by only 0.2-0.7 o C.
Exposure of these warmwater-acclimated grayling to solutions of the reference
toxicant pentachlorophenol caused a more definitive response.Sublethal strengths
of pentachlorophenol (0.4 and 0.7 of the 96-h LCSO value)reduced the critical
thermal maxima for grayling by 0.9 and 1.8 C respectively;a strength equivalent
to 1.2 LCSO caused a further reduction (Table 10).Variances (SD values)in
temperature at death were also increased by this toxicant.
Mean critical thermal maxima for the groups of grayling accl imated to SoC
water and tested in freshwa ter only were 24.8-24.9 0 c.Upper lethal temperatures
for these coldwater-adapted fish were not reduced by any yaydirt suspensions to
which they were exposed,up to and including SO,OOO mgoL-(Table 11;Fig.12).
Standard deviations calculated for each group (including control fish)were
greater than any found for groups of grayling acclim~ted to lSoc.
The median effective concentration (ECSO)of paydirt causing a net
significant decline in critical thermal maxima for grayling acclimated to lSo C was
100 mgoL-l (9S%confidence interval,SO-SOO);whereas that derived for overburden
was 8,471 mgoL-1 (1,S74->SO,000).No value could be calculated for the coldwater-
acclimated grayling exposed to paydirt suspensions,as no response to sediment was
observed.
The upper lethal temperature tolerance for Arctic grayling,determined in
this study for groups of fish held in clear freshwater only,was similar to values
derived previously under identical procedures using underyearling coho salmon or
rainbow trout (McLeay and Howard 1977;McLeay and Gordon 1980).LaPerriere and
Carl son (1973)reported earlier,that the (high)thermal tolerance of various life
stages of Arctic grayling was similar to other salmonid fish species.The
increased resistance to high temperature with an increased temperature of
acclimation (lSOC vs SOC)noted for grayling in the present study is also
consistent with earlier findings for other species of salmonid fish (Brett 19S2;
Black 19S3).TIle seasonal photoperiod to which fish are acclimated can also
influence thermal tolerance (McLeay and Gordon 1978).TIlus differences noted in
temperature tolerance of grayling acclimated to ISO or SoC probably reflect the
effect of a number of variables (i.e.seasonal photoperiod,developmental stage of
fish,fish condition)besides the temperature to which fish were acclimated.
-24 -
Sublethal concentrations of a number of aquatic contaminants (i.e.pulpmill
effluent,herbicides,certain heavy metals)have been shown previously to cause a
concentration-related decrease in the temperature tolerance of salmonid fish
(McLeay and Gordon 1978,1980).The degree to which this tolerance is impaired is
contaminant-specific;and findings to date indicate that contaminants which block
oxygen exchange at the gills,or otherwise impair tissue respiration,cause a
greater effect than those which exert their toxic effects in other ways (Wedemeyer
and McLeay 1981).
Since sublethal strengths of some aquatic contaminants can lower the upper
lethal temperature tolerance of sa1monid fish by as much as 4-S o C (McLeay and
Gordon 1978,1980),the minimal «l o C;lS o C fish)or negligible (SOC fish)
responses caused by exposing grayling to very high concentrations of suspended
inorganic or organic sediment indicate that these sediment loadings do not
interfere to a large extent with the immediate thermal adaptive capacity of
grayling.These findings,considered together with findings of thermal tolerance
effects noted previously for sa1monid fish and other aquatic contaminants,suggest
that short-term exposure of juvenile grayling to high loadings of suspended
sediment may not impair their tissue respiration to a significant extent.
Nevertheless,the threshold-effect (ECSO)levels of 100 mg e L-1 (paydirt)and 8,471
mg e L-1 (overburden)determined for the lSo C-acclimated grayling indicate that a
measurable reduction in critical thermal maxima for these fish was caused by these
and higher sediment strengths.The envirornnenta1 relevance of this response
cannot be ascertained without further studies.
The greater reduction in critical thermal maxima values for grayling exposed
to pentachlorophenol in this study was consistent with that for other sa1monid
fish species challenged with this reference toxicant (McLeay and Gordon 1980).
This finding indicates that'the tolerance of grayling to temperature extremes is
similarly influenced by this aquatic contaminant,and that the magnitude of effect
is dependent on both the nature and concentrations of toxicant to which fish are
subjected.
Sealed jar bioassays
Mean times to death for groups of warmwater-acclimated (lSOC)grayling held
in jars containing various strengths of paydirt sediment increased progressively
with concentration (Table 12,Fig.13).However,mean residual oxygen values for
each treatment did not differ from control values (Table 12,Fig.14).A repeat
of this bioassay test using paydirt suspensions and coldwater-accl imated (SOC)
fish showed no effect of this inorganic sediment on either times to death or
residual oxygen values at death of these fish (Table 13,Figs.IS and 16).
Unlike these findings,times to death for groups of grayling held in jars
containing suspensions of overburden decreased progressively with increasing
sediment strength (Table 14,Fig.17).Residual oxygen values for each treatment
were somewhat more variable than was found for fish held in paydirt,but showed no
consistent change with respect to concentration (Table 14,Fig.18).
Median effective concentrations (nominal)of paydirt or overburden which
affected times to death of the lSoC-acclimated grayling were 4,407 mg'L-1
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(Z97-ZZ,933 mg °L-1)and 161 mg °L -1 (4-615 mgoL -1),respectively.Thresho1d-effec t
concentrations could not be calculated for residual oxygen levels due to the
absence of consistent responses of this variable in each of the sealed jar
bioassays conducted.
Mean test temperatures (ZO.0-ZO.5 0 C for 150 C-acclimated fish;9.Z-9.9 0 C for
5 0 c-acc1imated fish)were held near-constant in each bioassay (Tables 1Z-14).
Concentrations of paydirt remaining in suspension at the end of each 30-min
settling period were decreased approximately Z-to 3-fo1d from respective values
for the freshly-agitated suspensions (Tables 1Z and 13).The overburden
suspensions to which fish were exposed in sealed jar bioassays settled to an even
greater extent (Table 14)prior to their re-suspension.
Grayling exposed to pentachlorophenol in sealed jar bioassays showed a
concentration-dependent increase in residual oxygen values,together with a
a progressive decrease in times to death of fish (Table 15).Sublethal strengths
of 35 ugoL-1 (0.5 of the 96-h LC50 value)and 50 ugoL-1 (0.7 LC50)elevated
residual oxygen values from those determined for each of the control (freshwater)
groups.
The tolerance of the warmwater-acc1imated grayling to hypoxia (oxygen
deficiency)was similar to that found previously for underyearling coho salmon Or
rainbow trout under identical test conditions (McLeay 1976;Gordon and McLeay
1977).The critical residual dissolved oxygen level at which each of these fish
species die,if acclimated to 15 0 C and held in freshwater at ZOOC,is
approximately Z.O mg 0ZoL -1.The even greater tolerance to hypoxic conditions
found in the present bioassays with gray1i~acclimated to 5 0 c and tested at 100 C
(critical value approximately 1.5 mg 0ZoL-1 )is also consistent with findings for
other sa1monid fish in response to a decrease in test temperature (Gordon and
McLeay 1977).LaPerriere and Carlson (973)cited field observations of Arctic
grayling under ice cover,where the dissolved oxygen concentration of the
surrounding water approached 0 mgoL -1.The present findings do not suggest a
greater capacity to adapt to hypoxic conditions for this species than has been
determined previously for other sa1monid fish.
The respiratory responses of grayling to pentachlorophenol (elevated residual
dissolved oxygen values,decreased times to death)are consistent with the
response to this reference toxicant noted for underyearling rainbow trout when
tested under identical conditions (McLeay and Gordon 1980).This toxicant is
known to increase the oxygen consumption rate of sa1monid fish,and is believed to
uncouple mitochondrial respiration (Chapman and Shumway 1978).
The progressive decline in times to death of grayl ing exposed to increasing
strengths of overburden (Fig.17)is likely due to the high oxygen demand
demonstrated for this organic sediment (Table Z),and does not reflect a
respiratory response of the test fish.On the other hand,the increase in mean
times to death for 150 c-acc1imated grayling,with increasing strengths of paydirt
(Fig.13),does suggest a reduction in respiratory rate attributable to this
inorganic sediment.This response could be due to increased swimming activity of
fish in the clear solutions,in response to visual "disturbance"during the
-26 -
bioassay.Alternatively,it could reflect decreased physical activity,reduced
ventilatory rate,or decreased efficiency of oxygen transfer,caused by
progressively higher strengths of paydirt.The significance of this response is
unclear in view of the lack of effect of these paydirt·suspensions on the fishes'
tolerance to hypoxia (Fig.14),and on the absence of a time-to-death response to
paydirt for grayling acclimated to cold water (Fig.15).
The effect of suspended sediment on the respiration rate of fish has not been
examined to any extent.Neumann et al.(975)reported no change in the
respiratory rates of oyster toadfish (Opsanus tau)held briefly in a 2,000 mg'L-1
suspension of natural sediment;although a 72-h exposure to 11,000 mg'L-1 caused a
greater variance in oxygen uptake rates compared with control fish.
Aquatic contaminants known to affect fish respiration normally cause a
concentration-dependent increase in residual oxygen levels of salmonid fish held
in sealed jars (McLeay 1976;Vigers and Maynard 1977);whereas those contaminants
known to exert their toxic effects otherwise may not effect this response (McLeay
and Gordon 1980).The absence of significant changes in residual oxygen values
for grayling held in suspensions of paydirt or overburden suggests either that
these sediments do not impair their tolerance to hypoxic conditions,or that the
strengths of sediment to which fish were exposed were too low to evoke a
response.The elevated residual oxygen values for grayling held in sublethal
strengths of pentachlorophenol confirm that these fish will indeed show a response
in this bioassay test to a contaminant known to affect fish respiration.The
absence of gill lesions associated with 4-day exposures of grayling to these
sediments,together with the 1 imited-if-any effects of paydirt or overburden
suspensions on their temperature tolerance,further support the suggestion that
short-term exposure of underyearling grayling to high suspended loadings of either
of these sediment types does not impact their respiratory capacity.
Acute stress bioassays
Hematocrit values for groups of warmwater-acclimated grayling held in
differing strengths of paydirt or overburden for 24 h were unchanged from
corresponding control values (Tables 16 and 17).However,mean leucocrit values
for these fish were consistently decreased by exposure to nominal sediment
strengths of 1,000 mg'L-1 and higher (Figs.19 and 20).Median effective
concentrations of paydirt and overburden causing this response were 51,651 mg'L-1
(2,381-)100,000 mg'L-1)and 5,843 mg~L-1 (2,092-29,107 mg'L-1),respectively.
Leucocrit values for the groups of control fish sampled at the beginning and end
of these bioassay tests did not differ appreciably (means,1.2-1.4%;Tables 16 and
17)•
Blood sugar values determined for these fish were also affected by sediment.
Results for fish exposed to differing suspensions of paydirt were inconsistent.
Generally,J:l!.eans and/or 95%confidence intervals for groups of fish exposed to
paydirt strengths of 500 mg'L-lor higher were increased from control values
(Fig.21);although blood sugar values for fish held in 5,000 mg'L-1 were
unchanged from those for the final control group.
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The elevated plasma glucose levels for the initial control group were
atypical of the final controls and of other groups of control fish (Tables
16-18).These inconsistencies prevented the calculation of a threshold-effect
concentration.
Plasma glucose values for groups of fish exposed to suspensions of overburden
were consistently elevated from those for control fish (Table 17;Fig.22).The
median effective concentration of overburden causing this response was less than
50 mgoL-1.
As with these acute stress bioassays,hematocrit values determined for the
groups of warmwater-acc1imated grayling surviving a 4-day exposure to inorganic or
organic suspensions were unchanged from values for controls (Tables 5 and 6).
Mean hematocrit values derived for all groups of coldwater-acclimated grayling
were again unaffected by sediment treatment;although these values were decreased
consistently from those for the warmwater-acc1 ima ted fish (Table 7).Leucocrit
values for all groups of coldwater-acclimated grayling examined (including control
fish)were declined from values for'warmwater-acc1imated fish held in freshwater
and were unchanged by treatment (Table 7).
Plasma glucose levels for all groups of coldwater-acclimated grayling
surviving a 4-day exposure to paydirt differed from those for the control group.
Paydirt concentrations of 500 mgoL -1 and higher caused a consistent increase in
sample means and 95%confidence intervals (Table 7;Fig.23).
Fish hematocrit values generally are highly correlated with both erythrocyte
(red blood cell)counts and blood hemoglobin content (Houston and DeWilde 1968,
1972).The decrease in hematocrit noted in this study for underyearling grayling
acclimated to cold water has been reported previously for other species of
sa1monid fish (Banks et a1.1971).
Hypoxic conditions cause significant increases in hematocrit values for
sa1monid fish (Ho1eton and Randall 1967;Swift and Lloyd 1974;Casillas and Smith
1977).However,changes in hematocrit values are somewhat resistant to acute
stress,including that caused by exposure of fish to sublethal concentrations of a
variety of aquatic contaminants (McLeay and Gordon 1977,1979,1980).
As in the present studies,Noggle (1978)reported that hematocrit values of
underyearling coho salmon were unchanged by holding fish for 96 h in suspended
sediment concentrations equivalent to 0.8 of the 96-h LC50 value.Other studies
with non-sa1monid fish species given short-term exposure to sediment have found
unchanged,elevated or depressed hematocrit values (Berry 1973;Neumann et al.
1975).
Unlike hematocrit values,1eucocrit values (or numbers of circulating
1eucocytes;i.e.white blood cells)for sa1monid fish can change rapidly and
dramatically in response to stress (MCLeay 1975;McLeay and Gordon 1977;Wedemeyer
and MCLeay 1981).Short-term exposure of rainbow trout or coho salmon to
sublethal concentrations of aquatic contaminants as low as 0.1 of the 96-h LC50
can cause significant declines in these values,provided that test fish are in
-28 -
good condition and unstressed beforehand (McLeay and Howard 1977;McLeay and
Gordon 1979,1980).The general decline in leucocrit values for warmwater-
acclimated Arctic gray1 ing held in suspensions of paydirt or overburden for 24 h
indicates that each of these sediment types was stressful to these fish.Values
for control groups were similar to those found previously for underyearling coho
salmon,and somewhat elevated from control values for rainbow trout (McLeay and
Gordon 1977).The absence of a consistent 1eucocrit response for the
coldwater-acclimated·grayling may reflect the influence of prior stress (i.e.
disturbances to all control and test fish during the 4-day exposure period)or
perhaps a differing mechanism of response to stress for co1dwater-versus
warmwater-acc1imated fish.
The stress reactions (depressed 1eucocrit values,elevated plasma glucose
values)found for grayling exposed for 24 h to sublethal strengths of
pentachlorophenol (Table 18)are typical of the acute responses shown previously
to be elicited for underyearling rainbow trout by this toxicant (McLeay and Gordon
1980).Diverse environmental stressors including sublethal strengths of aquatic
contaminants are known to cause a rapid elevation and/or increased variance in
blood sugar levels for groups of sa1monid fish (McLeay 1977;Wedemeyer and McLeay
1981).A consideration of the blood sugar changes found in the present tests ,
together with the 1eucocrit changes for sediment-exposed fish,confirm that
sublethal strengths of the paydirt and overburden suspensions examined were indeed
acutely stressful to Arctic grayling.The variations in plasma glucose levels
noted for coldwater-acclimated grayling exposed .tosuspensions of paydirt for 96 h
indicate that grayling are stressed by this inorganic sediment,regardless of
season or acclimation temperature.
Other studies of the hematological effects of sediment suspensions on fish
are limited.Noggle (1978)found that blood sugar values for goups of coho salmon
held for 96 h in inorganic sediment suspensions >0.2 LC50 were significantly
changed from those for control fish.Similarly,O'Connor et a1.(1977>reported
that the laboratory exposure of a number of species of estuarine fish to
suspensions of natural sediments caused hematological changes indicative of stress
responses.
General
The threshold-effect concentrations (EC50)of paydirt or overburden
suspensions calculated to cause acute responses for Arctic grayling in the present
series of laboratory bioassays are stllD.marized in Table 19.The EC50 values
presented are based on nominal (pre-weighed)strengths of sediment to which fish
were exposed.From these data it can be seen that the acute lethal tolerance of
both warmwater-and coldwater-acclimated grayling to suspensions of organic and/or
inorganic sediment was too high to permit the calculation of LC50 values.For
fish acclimated to l5 0 C,threshold-effect values were derived for some of the
sublethal responses monitored (i.e.critical thermal maxima;leucocrit;time to
death in sealed jar bioassays);whereas values could not be determined for other
tests due to the absence of effect (i.e.residual oxygen)or increased variability
of response (i.e.plasma glucose values for paydirt-exposed fish)caused by
treatment.No threshold-effect values could be derived for fish acclimated to 5 0 C
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-29 -
and challenged with differing suspensions of paydirt due to the absence (in the
temperature tolerance and sealed jar bioassays)or increeased variability of
responses (in the acute stress test)caused by sediment exposure.
As with other hematological changes,variations in blood sugar values or
blood cell counts (including 1eucocrit values)of fish in response to
enviromnenta1 alterations reflect a nwnber of dynamic adaptive reactions.Such
changes in regulatory precision of blood constituents may be evident by upward or
downward shifts in values from the norm,although effects are also shown in many
instances by increased variations in sample values from the normal range (B1axha11
1972;Wedemeyer and Nelson 1975).The present changes noted in blood sugar and
1eucocrit values of grayling due to suspensions of inorganic or organic sediment
are consistent with these homeostatic effects.In such instances,the calculation
of EC50 values based on a net significant increase (for blood sugar)or decrease
(for 1eucocrit)of these values is inappropriate (Table 19).Derivation of
meaningful threshold-effect concentrations for these tests would require the
determination of normal ranges of these blood constituents for control fish,using
a large sample size (n)200)(Wedemeyer and Nelson 1975).Individual values for
each sediment-exposed fish would then be examined to determine if they were within
this range.
The present laboratory bioassays with inorganic and organic sediment indicate
that these sediment types can cause dissimilar sublethal effects for Arctic
grayling (i.e.time to death in sealed jar bioassay),or may differ appreciably in
threshold-effect concentrations (Table 19).The nature of suspended sediment
(including particle constituents,size and angularity),water velocity and other
enviromnenta1 variables may contribute significantly to the manner and extent to
which it causes adverse biological effects.
FIELD STUDIES
Water quali ty
A swnmary of the results of all water quality sampling is presented in Tables
20 and 21.Detailed water quality data are presented in Appendices 5 through 9.
The data indicate that turbidity and nonfi1trab1e residue were elevated in aighet
Creek which was being mined,relative to Minto Creek upstream of the junction,
during both August and September.Total volatile residue (organic material)was a
small component of total residue in both streams.Turbidity in Highet Creek in
August ha·d a mean value of 51 FTU and a range of 3 to 250 FTU,whereas in
September mean turbidity was higher (636 FTU)and ranged from 100 to 2,250 FTU
(Appendices 5 and 6).The mean turbidity level in Minto Creek during August was
1.1 FTll (range,0.7 to 1.8 FTU)and,in September,was 0.9 FTU (0.5 to 1.8 FTU).
Nonfi1trab1e residue (suspended solids)reflected the same trends as turbidity for
the two streams (Table 20),indicating the substantially higher load of suspended
material being transported in Highet Creek as a result of placer mining activity
upstream.Inclusion of dissolved solids with suspended solids (total residue)did
not appreciably alter this similarity.
-30 -
Turbidity and total residue in Highet Creek during the two test periods
showed similar trends and are illustrated in Figures 24 and 25.Turbidity and
total residue were lower in Highet Creek in August than they were in September,
reflecting differences in mining activity.The maximum total residue in August
was 294 mg!L-l but in September reached 1,900 mg·L-I .It is apparent upon
examination of Figs.24 and 25 that the suspended sediment concentration at the
test site was consistently higher between 1800 hand 0800 h each day.The
approximate 10-h delay between the daily onset of mining ("'0800 h)and the
increase in sediment concentration was due to the travel time for transport of
sediment between the test site and the mining operations,together with the
retention time of the settling pond.
Particle size analysis of suspended solids within Highet Creek is shown in
Table 22.The distribution of particles was similar between the two test
periods.These analyses showed that all solids were less than 400 urn in
diameter.Solids between 2 and 50 urn in August comprised 83.9%of the material,
and in September 88.7%of the material.
Comparison of residue and turbidity values for Highet Creek water samples
from inside and outs ide the net enclosures showed inconsistent results.
Nonfiltrable residue concentrations in the grab samples were usually highest,
averaging approximately 50%greater than automatic sampler values (Appendix 9).
How-ever,total residue and turbidi ty levels for samples taken wi thin or outside of
the cages showed much smaller differences.
Dissolved oxygen remained near saturation in both streams during the two
study periods (Table 20).Both Minto and Highet creeks exhibited circurnneutral
pH,with Highet Creek ranging between 6.9 and 7.9 during the two study periods and
Minto Creek ranging from 6.5 to 7.5 during the same time periods.Water
temperature was also monitored and showed variability between the two sites.
The temperature of Minto Creek water at the study site was relatively stable
during each of the two test periods,ranging from 120 to 14°C in August and 50 to
7 0 C in September (Table 20).Temperature was probably maintained within these
small ranges due to the stabilizing effect of Minto Lake,a few kilometres
upsteam.Highet Creek exhibited the more usual temperature variation of free
flowing streams which are more responsive to changing air temperatures.Water
temperatures in this or other streams being mined may also be influenced through
the use of the stream in removing frozen or cool temperature soils material.
Temperatures in Highet Creek during August ranged from 7 0 to 120 C and during
September,from 1 0 to 9 0 C (Table 20).The studies had been planned to coincide
with warm water periods in August and cool water periods in September.This was
achieved,although daily temperature regimes in the two streams were somewhat
different.
Several water quality characteristics for Minto and Highet creeks were
determined at the beginning and conclusion of the two test periods.In addition,
a single determination of the same characteristics was made on Mud Creek water,as
some fish for the second test came from this creek.Results of all samplings are
shown in Table 21.These data show the normal slight increase in hardness and
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alkalinity with increasing contribution of groundwater flows in late summer low
flow periods.Hardness and alkalinity values were highest in Mud Creek (141 and
120 mgoL-1,respectively);slightly lower in Minto Creek (110 to 123 mgoL-l and
100 to 112 mgoL-1,respectively);and lowest in Highet Creek (73 to 80 mgoL-1 and
50 to 52 mgoL-1,respectively).As expected,calcium was the predominant anion in
the three streams,ranging from 23.0 to 41.4 mgoL-l ,whereas magnesium ranged from
3.3 to 9.1 mgoL-l (Table 21).
Analysis showed that most metals were either not different in concentration
between streams,or were below the analytical detection limits (Table 21).
Particular metals of concern Which were below detection limits at all times were
lead,copper,mercury,and cadmium.Iron was found to be lower than detection
limit in Mud Creek,and ranged from 0.1 to 0.5 mgoL-1 in Minto and Highet creeks.
Strontium was found to be higher in Minto and Mud creeks (0.20 to 0.23 mgoL -1)
than in Highet Creek (0.12 to 0.14 mgoL-1 ).Tin was above detection limit only
during September in Highet Creek,when levels of 0.11 to 0.17 mgoL-l were
reached.No guidelines have been established for the protection of aquatic biota
for either strontium or tin (McNeely et al.1979).
Four other metals (arsenic,manganese,zinc,and aluminum)were found to
exceed recommended levels or tentative limits for the protection of aquatic biota
on at least one occasion within the study area.Arsenic was above detection
limits in Highet and Minto creeks only during August (Table 21).Levels in Minto
Creek ranged from 0.01 to 0.07 mgoL-1 ,whereas in Highet Creek levels reached 0.1
to 0.2 mgoL-l •Arsenic levels defined as hazardous in the aquatic environment are
0.05 mgoL -1,or 0.01 mgoL -1 as presenting minimal risk to aquatic organisms
(McNeely et ale 1979).Manganese was not detectable in Mud Creek or Minto Creek
in September.However,manganese was found to be 0.014-0.016 mgoL-1 in Minto
Creek during August,and,in Highet Creek,0.013 to 0.027 mgoL-1 in September and
0.048 to 0.052 mgoL-1 in August.Higher levels of manganese were found in August
in the two study streams and in Highet Creek exceeded the recommended level of
0.02 mgoL -1 (McNeely et al.1979)in both periods (but only marginally in
September).Zinc was detectable at all sites on all occasions (Table 21).Minto
Creek zinc concentrations ranged from 0.02 to 0.03 mgoL -1,and Highet Creek
concentations ranged from 0.02 to 0.05 mgoL-l.The recommended level of zinc for
the protection of aquatic organisms is 0.03 mgoL -1 (McNeely et ale 1979),which is
met or exceeded marginally in both study streams.Aluminum concentrations were
found to be highest in August in both study streams and higher in Hi~het Creek
than Minto Creek.Minto Creek levels ranged from <0.05 to 0.05 mgoL - ,whereas
concentrations in Highet Creek ranged from 0.1 to 0.3 mgoL -1.No recommended
limits for aquatic organism protection have been established for aluminum,
although a tentative limit of 0.1 mgoL -1 has been identified (McNeely et al.
1979).
As indicated,four metals were found to exceed recommended or tentative
1 imits for total metals derived for the aquatic environment.The metal values
indicated in the present report are total levels;that is,all forms of the metal,
whether combined with other elements,adsorbed to particles,or ionic.It is
known that most metals are not acutely toxic to aquatic organisms in the non-ionic
-32 -
state,and that toxicity ~s not directly related to total metal values.In
addition,at the pH and relatively high calcium levels found in the study area,it
is expected that a large portion of the total metals measured would be in a
non-ionic state.
Caged fish studies
Fish survival
During the August tests,all grayling held for four days in cages within
Highet Creek or Minto Creek were alive (Table 23)and in apparently good condition
at the end of this exposure period.No signs of fish distress or injury were
evident at either site.Similarly,all grayling captured from Minto Creek and
held at the Highet and Minto Creek sites for five days during September 1982,
survived.However,16%(five fish)of the Mud Creek fish held in Highet Creek
during September died within 96 h (Table 23).All Mud Creek fish held in cages
within Minto Creek survived the l20-h (5-day)test period.
Although Mud Creek fish held in Minto Creek survived the test period while 5
of the 32 Mud Creek fish in Highet Creek died,it cannot be stated with certainty
that suspended sediment (nonfiltrable residue)was the sole factor contributing to
these fish deaths.Additionally,since all but one of these five fish survived
the initial 48-h period following their transfer from Mud Creek (Table 23),the
fish deaths were not caused by transfer shock alone.Perhaps these fish were
unable to withstand the stress loading imposed upon them by the combined effects
of capture,transport,confinement and the more rigorous environmental conditions
within Highet Creek (daily fluctuations of water temperature to near zero,
together with suspended sediment concentrations ~1,2l0 mgoL-l ).
Our findings that wild Arctic grayling in stream environments can survive
short-term exposure to suspended sediment concentrations of up to 1,210 mgoL-l are
in general agreement with other field observations for this salmonid fish
species.In a similar study,Simmons and LaPerriere (1982)found that
underyearling Arctic grayling held for 7-10 days in the highly turbid ()1,000 NTU)
water of Birch Creek,downstream of placer mining'activities,-survived.
Atkins-Baker (MS,1980)also reported 100%survival of fingerling grayling held
for 4 days in Hunker Creek when suspended sediment strengths ranged from 335 to
22,000 mg °L -1;although mortalities of caged fish were noted for other creeks in
association with·peak loadings of suspended sediment.Mathers et al.(1981)
captured adult grayling during July from other Yukon creeks (Clear,Duncan,
Johnson)receiving placer mining effluent,at time~when suspended sediment
concentrations varied from 114 to 4,453 mgoL-1 ,whereas fry were not found.These
investigators did note,however,"On the other hand,good catches of grayling,
both adults and fry,were obtained in Sulphur Creek.In this area suspended
sediment concentrations were about 100 mgoL-l".
Gill histology
All gills of fish caged in Highet or Minto Creek during August or September
appeared "normal"when inspected upon termination of these field bioassays.No
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@\'~,:loss of red coloration was evident,and clogging of filaments with sediment
particles was not observed.Additionally,no signs of increased mucous production
were seen on either occasion for gills of fish caged in Highet Creek.Subsequent
I\licroscopic examination of gill arches preserved with polyvinyl lactophenol also
fevealed no damage to gill filaments of fish held at either site on these
occasions •.
The detailed examination of gill tissues from grayling held in cages within
Minto or Highet Creek during September 1982 showed histopathological changes at
each site.Whereas the structure of gill filaments and secondary lamellae for
uncaged fish captured directly from Minto Creek at this time was normal in
appearance (Fig.26),that of fish held captive in both Minto Creek and.Highet
Creek was not (Fig.27).Moderate-to-marked hypertrophy (increase in cell size)
and hyperplasia (increase in cell number)of the lamellar epithelium was evident
for gills of all caged fish examined (Table 24).Additionally,the frequency of
gill ectoparasites (tentatively identified as monogenetic trematodes)noted
occasionally for three of the five uncaged upstream Minto Creek fish examined was
increased appreciably for fish caged at each site (Figs.26 and 27;Table 24).
With the exception of the infrequent observations of particulate debris (sediment)
between gill filaments of fish caged in Highet Creek,no differences in gill
histomorphologies for fish caged in Highet Creek versus Minto Creek were evident.
Wobeser et a1.(1976)reported severe lamellar hyperplasia for gill tissues
of captive Arctic grayling infested with large numbers of monogenetic
trematodes.Birtwell et ale (1983)also found extensive gill histopathologies for
adult Arctic grayling captured from Minto Creek downstream of its junction with
Highet Creek.The present association of gill lesions with increased numbers of
ectoparasites for caged grayling suggests that the histopathologies noted were
caused by these parasites.Other investigators (Williams 1967;Kearns 1968)have
reported a rapid buildup of gill parasites for wild fish held in captivity,as was
found in this instance.
The absence of any increased gill mucous production or of histopathological
changes attributable to the suspended sediment loadings to which grayling were
exposed in Highet Creek is consistent with our laboratory findings.Unlike these
results,Simmons and LaPerriere (1982)observed increased gill mucous secretions
for wild underyearling Arctic grayling held for 7-10 days in turbid water
downstream of placer mining activity.In a separate field study,Herbert et ale
(1961)reported gill lesions for trout captured from sediment-laden streams,
whereas those taken from clearwater streams were normal.However,these
differences may have resulted from prolonged exposure of fish to sediment.The
conflicting reports from field or laboratory studies of the presence or absence of
gill histopathologies attributable to exposure of fish to suspended sediment
suggest that factors such as particle type (shape,size),sediment concentrations,
and duration of fish exposure likely determine whether or not direct damage to
gill tissue will occur.
-34 -
Hematology
The hematocrit values determined for groups'of fish held in Minto Creek or
Highet Creek during August and September were similar;and apparently unaffected
by the differing water quality conditions noted for each site.On the other hand,
plasma glucose values determined for the grayling sampled from Minto Creek cages'
or directly from Mud Creek during August 1982 were similarly and consistently low;
whereas mean glucose values for fish sampled from the Highet Creek cages at this
time were elevated by approximately 30%(Table 25).Mean blood sugar values for
grayling held in Highet Creek during September were increased from those for fish
caged in Minto Creek by greater than 100%,regardless of fish source.These
findings suggest that the water quality conditions to which grayling were exposed
in Highet Creek,on each of the two occasions that the field bioassays were
conducted,were more stressful to these fish than those within Minto Creek.
Our findings from controlled laboratory bioassays with inorganic or organic
sediments indicate that suspended sediment strengths wi thin the range of those
found in Highet Creek during August or September can cause changes in blood sugar
and leucocrit values,which typify short-term reactions to stressors.The
relatively colder and more variable water temperatures for Highet Creek during
August and September (Table 20)may also account for the site-specific differences
in plasma glucose values noted on each occasion.During the extended period
required for salmonid and other fish species to acclimate to cold water,a number
of physiological stress responses normally occur,including the elevation of blood
sugar levels (Schuh and Nace 1961;Nace and Schuh 1961;Allan 1971).The capture,
transport,and confinement of fish can also cause appreciable changes in their
blood sugar regulation (Silbergeld 1974;Hattingh 1976;McLeay 1977).Thus the
elevated blood sugar values noted for grayling caged in Highet Creek
likely reflect the combined influence of suspended sediment together with other
stressors such as fluctuating water temperatures.
CONCLUSIONS
The present laboratory bioassays demonstrate that underyearling Arctic
grayling can survive short-term exposure to very high levels ()50,000 mgoL-1)of
suspended inorganic or organic sediment.Season (including acclimation
temperature)does not cause any marked changes in this tolerance,although test
results suggest a slight reduction in lethal tolerance to suspensions of inorganic
paydirt for grayling acclimated to cold (5 0 c)water.These laboratory findings
are consistent with the fish-survival data obtained for grayl ing held in turbid
waters downstream of placer mining activity for 4 or 5 days.
No gill histopathologies were found in either laboratory or field tests which
could be attributed to acute exposure of grayling to sediment.Additionally,the
laboratory bioassays indicated that the tolerance of grayling to hypoxic
conditions or to upper lethal temperatures was not appreciably affected by
suspensions of inorganic or organic sediment.The environmental significance of
the slight but consistent decrease in critical thermal maxima for
warmwater-acclimated grayling exposed to paydirt suspensions )100 mg °L -lor to
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-35 -
suspensions of overburden >8,000 mg·L-1 (based on EC50 values)is not known at the
present time.Nor is the significance of the increased time to death (reduced
oxygen uptake rate)for warmwater-acclimated grayling only,caused by paydirt
suspensions >4,000 mg·L-1,understood.The finding of decreased times to death
for grayling-held in sealed jars containing overburden concentrations >160 mg·L-1
is thought to reflect the oxygen demand of this organic muck.The environmental
relevance'of this oxygen demand is site-specific,and would be modified markedly
by factors such as overburden type and loading to receiving waters,flow
"condi tions,water temperature and presence or absence of ice cover.
The acute stress bioassays demonstrate that suspensions of both paydirt and
overburden can be acutely stressful to underyearling Arctic grayling.Further
the test results indicate that suspended sediment strengths as low as 50 mg·L-I
(overburden)may be stressful to these fish;and that stress responses can be
evoked for both co1dwater-and warmwater-acclimated fish.Differences in blood
sugar values noted on each of two occasions for grayling caged in Highet versus
Minto Creek also suggest that the Highet Creek site was more stressful to these
fish.The environmental relevance of these responses to the immediate survival
and long-term wellbeing of Arctic grayling cannot be ascertained without further
studies.However,stressful conditions are well known to reduce the·adaptive
responses of other salmonid fish species to natural environmental fluctuations,
and to increase the susceptibility of fish to disease (Wedemeyer et ale 1976;
Wedemeyer and McLeay 1981).
Resul ts from the present laboratory and field studies should provide some
direction for future investigations concerned with the acute or long-term
biological effects of suspended sediment on resident fish species,and.with
appropriate water quality objectives for sediment.The influence of sediment
concentration and type (including particle shape and size)which causes stress
responses in fish (and the environmental significance of these responses)deserves
further attention,as does the impact of more prolonged exposures.Effects of
sediment type and strength on fish behavioural responses (i.e.feeding,
avoidance/preference reactions)and on other life stages are also largely unknown
at present.A basic understanding of the degree to which these responses may be
altered by sediment is essential before the biological relevance to Arctic
grayling or other sensitive aquatic species of specific sediment loadings within
natural waterbodies can be fully appreciated.
ACKNOWLEDGEMENTS
We wish to thank Mr.W.G.Whitley (Director,Yukon River Basin Study)for his
support and technical advice during this study;Mr.H.F.McAlpine (Dept.Indian &
Northern Affairs)for the provision of historical information and the ISCO
samplers;and Messrs.S.Roxburgh (Fisheries &Oceans Canada),H.F.McAlpine and
D.Davies for their help in site selection.The technical assistance of Dr.N.
Lowes (gill histology),Mr.D.Bradley (fish maintenance),and the Environment
Canada/Fisheries and Oceans laboratory at West Vancouver (water quality analyses)
are gratefully acknowledged.Our thanks are also expressed to Mr.L.Hildebrand
for his technical efforts during all aspects of the laboratory bioassays,to Mr.
M.C.Nelson for his assistance in carrying out the field portion of the study,
Mrs.S.C.Jones for drafting,and to Ms.L.Borleske for her typing and drafting
skills.
\
-36 -
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....
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~[
[
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[
[
[
[
[
[
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~[
[
[.,l J l J
TABLE 1.Particle size distribution for paydirt and overburden sediment samples.
Sieve Particle Paydirt (test no.1)Paydirt (test no.2)Overburden
size size
(mesh)(llm)weight cumulative weight cumulative weight cumulative ,,"-
(%)we i'ght (%)weight (%)weight
(%)(%)(%)
+35 >400 0.0 0.0 0.0 0.0 31.0 31.0
+48 >300 0.0 0.0 0.1 0.1 9.5 40.5
+65 >210 0.2 0.2 0.7 0.8 8.9 49.4 .p-
I-
+100 >150 1.5 1.7 3.8 4.6 11.2 60.6
+150 >100 6.9 8.6 8.9 13.5 9.2 69.8
+200 >75 9.4 18.0 9.2 22.7 7.3 77 .1
+325 >45 9.8 27.8 9.4 32.1 8.6 85.7
+400 >38 6.8 34.6 7.5 39.6 11.0 96.7
-400 <38 65.4 100.0 60.4 100.0 3.3 100.0
-42 -
TABLE 2.Moisture content,volatile and fixed residue,and oxygen
uptake rate for paydirt and overburden sediment samples.
[
[
I
Characteristic Test
No.
Sediment type [
paydirt overburden
1 2.3 81.8
moisture content (%)2 2.8 84.6
3 2.5 82.5
volatile residue (%)1 3.6 96.0
fixed residue (%)1 96.4 4.0
0 1 0.01 0.08oxygenuptakerateat15C
(mg 02 'ml-1 sediment-24 h-1 )2 0.01 0.08
0 1 0.01 0.6oxygenuptakerateat15C
(mg °2-g-1 sedimenta -24 h-1 )2 0.01 0.6
aBased on dry weight.
[
[
[
[
o
[
[
[
[
[
[
.[
[
Metal contenta of paydirt and overburden sediment samples.
Concentration
(%dry weight)
[
[
[
TABLE 3.
Major components
-43 -
paydirt overburden
Trace components Concentration
(~g'g-l dry weight)
aBased on analysis of sediment digest by inductively coupled
argon plasma spectrograph.
[
[
[
...
[
[
[
[
l
[.
[
alumina
iron
calcium
magnesium
sodium
potassium
antimony
arsenic
barium
beryllium
bismuth
cadmium
chromium
cobalt
copper
lead
manganese
molybdenum
nickel
phosphorus
silver
strontium
tin
titanium
vanadium
zinc
A120g
Fe20g
CaO
MgO
Na20
K20
Sb
As
Ba
Be
Bi
Cd
Cr
Co
Cu
Pb
Mn
Mo
Ni
P04
Ag
Sr
Sn
Ti
V
Zn
12.8
11.0
0.32
0.91
0.59
2.45
paydirt
73.8
1,570.
732.
<0.3
<50.
<1.
136.
<5.
56.1
<10.
545.
<4.
39.7
1,740.
<0.5
83.5
<3.
3,090.
70.4
94.6
1.12
0.91
5.18
0.36
0.11
0.10
overburden
<15.
<30.
743.
<0.3
<50.
<1.
4.3
<5.
43.3
<10.
2,920.
<4.
32.1
3,970.
<0.5
156.
<3.
229.
8.9
92.0
-44 -
()
[
r
L
aA1iquots (100 m1)taken for total residue analyses at 48 h after test
sediment introduced to tanks.
TABLE 4.Effect of location within recycle test tanks on co~centration
(total residue values)a of recirculating paydirt sedimento
Nominal
paydirt strength
(mgoL-1 )
500
5,000
10,000
20,000
100,000
Total residue
(mgoL-1 )
tank surface mid-depth bottom
inflow (mid-tank)(mid-tank)(corner)
857 412 380 222
7,440 3,360 3,367 4,006
21,488 8,249 8,605 10,436
37,624 13,968 15,386 18,726
351,536 62,391 71,536 85,259
1~
[
[
[
[
[
[
...
[
[
[
[
[
[
[
.[
.[
[
J c,:]J J j I
"
TABLE 5.Acute survival test:Effect of a 4-day exposure to suspended inorganic paydirt
fines on fish survival and on blood sugar and hematocrit values for underyearling Arctic
graylinga acclimated to 15°C.
Paydirt concentration Fish survival Plasma glucose Hematocrit
(mgoL-1 )(%)(mg %)(%)
.lb final 24h 48h 72h 96h Mean SD Mean SDnoml.na
suspended
residuec
0 0 100 100 100 100 129.8 59.1 30.6 1.9
50 76 100 100 100 100 104.2 25.5 31.6 2.8
100 261 100 100 100 100 132.2 31.3 31.0 1.6
1,000 1,090 100 100 100 100 97.6 20.8 30.4 2.1 I
5,000 5,401 100 100 100 100 65.6 5.1 33.2 2.3 .j::-
VI
10,000 17,390 100 100 100 100 61.0 6 •.2 30.2 1.9
50,000 87,768 100 100 100 100
_d
100,000 237,959 100 100 100 100 56.6 7.5 32.6 4.7
250,000 100 100 100 100
~Mean (±SD)weight,2.9 ±0.7 g;length,7.1 ±0.6 cm;condition factor,0.79 ±0.05.
Based on weight of paydirt added to a 50-L test volume.C ''dBased on total residue for a 100-ml grab sample taken from the pump outlet at end of test.
Not determined.
TABLE 6.Acute survival test:Effect of a 4-day exposure to suspended organic overburden on
fish survival and on blood sugar and hematocrit values for underyearling Arctic graylingaac-
climated to 15°C.
Overburden concentration Fish survival Plasma glucose Hematocrit
(mgoL -1)(%)(mg %)(%)
.lb final 24h 48h 72h 96h Hean SD Mean SDnoml.na
suspended
residuec
I
~
0 3 100 100 100 100 127.8 102.4 32.3 1.9 0\
. I
50 29 100 100 100 100 90.8 7.7 32.0 2.2
100 104 100 100 100 100 88.4 10.4 30.6 1.8
1,000 889 100 100 100 100 102.4 38.2 32.1 2.0
5,000 2,172 100 100 100 100 87.8 6.8 31.9 1.8
10,000 4,165 100 100 100 100 94.3 39.7 32.5 2.1
50,000 10,320 100 100 100 100 102.6 22.7 32.8 1.3
~Mean (±SD)weight,3.6 ±1.0 g;length,7.8 ±0.7 cm;condition factor,0.75 ±0.04.
Based on dry weight of overburden added to a 50-L test volume.
cBased on total residue fora 100-mlgrab sample taken from centre of tank at end of test.
r-l r--::
1
TABLE 7.Acute survival test:Effect of a 4-day exposure to suspended inorganic paydirt fines on fish sur-
vival and on blood sugar,leucocrit and hematocrit values for underyearling Arctic graylinga acclimated to
5°C.
Paydirt concentration Fish survival Plasma glucose Hematocrit Leucocrit
(mg.L-1)(%)(mg %)(%)(%)
.lb final 24h 48h 72h 96h Mean SD Mean SD Mean SDnoml.na
suspended ~
residuec 'l
a 7 100 100 100 100 57.3 15.9 28.8 3.5 1.12 0.38
500 110 100 100 100 100 118.7 49.5 28.4 3.4 0.96 0.42
5,000 2,455 100 100 100 100 71.4 16.6 29.3 3.0 1.18 0.40
10,000 8,602 100 100 100 100 68.5 50.0 28.0 4.4 0.80 0.32
20,000 15,847 100.100 90 90 99.1 62.8 28.4 7.6 1.10 0.27
100,000 70,569 100 100 80 80 123.4 115.8 30.6 4.8 0.98 0.40
~Mean (±SD)weight,4.5 ±1.3 g;length,8.4 ±0.8 cm;condition factor,0.76 ±0.09.
Based on weight of paydirt added to a 50-L test volume.
cBased on total residue for a 100-ml grab sample taken from centre of tank at end of test.
-48 -
TABLE 8.Temperature tolerance test:Effect of suspended inorganic
paydirt on the critical thermal maxima for underyearling Arctic gray-
linga acclimated to 15°C.
a Mean (±SD)weight,5.1 ±0.9 g;length,8.3 ±0.4 cm;condition
factor,0.90 ±0.06.
bBased on weight of paydirt added to test volume.
cBased on total residue for 100-m1 grab sample taken from centre
of vessel at end of test.
Temperature (OC)at death
[
l~
I
[
[
[
[
[
[
'-
[
[
[0.
[
[
[
SD
27.9 0.1
27.7 0.1
27.3·0.1
27.8 0.2
27.4 0.1
27.8 0.3
27.2 0.1
27.3 0.1
27.2 0.3
27.0 0.1
27.0 0.1
27.1 0.1
26.6 0.2
26.7 0.2
Mean
Paydirt concentration
(mg·L-I )
nomina1b final
suspended
residuec
0 (test 1)0
0 (test 2)0
25 28
50 76
100 (test 1)129
100 (test 2)85
500 490
1,000 (test 1)640
1,000 (test 2)780
5,000 3,410
10,000 6,200
20,000 11,000
50,000 61,272
100,000 82,275
L
~[
[
[-49·-
r
TABLE 9.Temperature tolerance test:Effect of suspended organic
overburden on the critical thermal maxima for underyearling Arctic
graylinga acclimated to 15°C.
aMean (±SD)weight,4.8 ±1.0 g;length,8.1 ±0.7 cm;condition
8factor,0.91 ±0.07.
aBased on dry weight of overburden added to test volume.
Based on total residue for 100-ml grab sample taken from centre
of vessel at end of test.
Overburden concentration
(rog'L-I )
0 (control)a
100 125
150 147
500 609
1,000 700
5,000 2,336
10,000 3,646
20,000 7,242
50,000 14,197
Temperature (oC)at death
SD
0.3
0.1
0.2
0.3
0.2
0.5
0.4
0.3
0.4
27.5
28.0
27.7
27.5
27.6
26.8
27.3
26.9
27.1
Meanfinal
suspended
residuec
nominalb[
n
[
[]
...
C
C
C
[
[
[
-50 -
TABLE 10.Temperature tolerance test:Effect of pentachloro-
phenol on the critical thermal maxima for underyear1ing Arctic
gray1inga acclimated to 15°C.
Pentachlorophenol Temperature (oC)at death
concentration
(l1g'L-1)Mean SD
0 (control)27.7 0.1
25 26.8 0.3
50 25.9 0.5
80 <25.5
a~ean (±SD)weight,4.9 ±0.9 g;length,8.2 ±0.5 cm;
condition factor,0.89±0.06.
[
[
[
[
[
[
.(.
[
c
[
[
[
l
r1 .
L
[
-51 -
TABLE 11.Temperature tolerance test:Effect of suspended inorganic
paydirt on the critical thermal maxima for underyearling Arctic gray-
linga acclimated to 5 °C.
Paydirt concentration
(mgoL-l )
0'Temperature (eoC)at death
0 (control 1)3
0 (control 2)5
100 40
500 260.
1,000 520
10,000 5,692
50,000 71,143
[
n
!
D
i:lominalb final
suspended
residuec
Mean
24.8
24.9
24.9
25;2
25.2
24.7
25.3
SD
1.5
1.4
1.5
2.1
0.8
1.1
1.3
r
L
[
[.
a Mean (::tSD)w-eight,5.5 ±2.3 g;length,8.5 ±1.8 cm;'condition
bfactor,0.81 ±0.12.
Based on weight of paydirt added to test volume.
cBased on total residue for 100-ml grab sample taken from centre
of vessel at end of test.
TABLE 12.Sealed jar bioassay:Effect of suspended inorganic paydirt on tolerance to hypoxia and
time to hypoxic death for underyear1ing Arctic gray1inga acclimated to 15°C.
Paydirt concentration Temperature at Time to death Residual oxygen at
(mg.L-1)death (oC)(min)death (mg Oz·L-1)
. 1
b initial final Mean SD Mean SD Mean SDnOTIl1.na
suspended suspended
residuec residued
0 <1 2 20.5 0.2 228 61 2.0 0.4 .
0 <1 1 20.5 0.1 224 58 1.9 0.2 .
100 107 52 20.5 0.1 220 58 1.9 0.2
U150038518020.5 0.1 270 60 1.9 0.3 N
2,500 1,836 420 20.5 0.1 245 73 1.9 0.3
10,000 8,127 2,670 20.3 0.1 271 71 1.9 0.3
20,000 15,483 5,997 20.4 0.1 2Q9 34 1.8 0.3
50,000 46,590 16,481 20.3 0.1 319 45 1.8 0.3
100,000 90,027 31,029 20.4 0.2 312 16 1.9 0.3
?Mean (±SD)weight,10.4 ±1.3 g;length,10.2 ±0.4 cm;condition factor,0.98 ±0.07.~Based on weight of paydirt added to each of ten replicate 1.9-L glass jars.
aBased on total residue for a 10D-ml grab sample taken immediately after the jar was inverted •
..Based on total residue for a 100-ml grab sample taken 30 min after the jar was inverted.
TABLE 13.Sealed jar bioassay:Effect of suspended inorganic paydirt on tolerance to hypoxia and
time to hypoxic death for underyear1ing Arctic gray1inga acclimated to 5°C.
Paydirt concentration Temperature at Time'to death Residual oxygen at
(mgoL-l )death (OC)(min)death (mg 02oL-I)
. 1
b initial final Mean SD Mean SD Mean SDnoml.na
suspended suspended
residueC residued
0 6 6 9.4 0.6 491 63 1.5 0.4
0 4 5 9.7 1.0 498 94 1.6 0.4
100 66 24 9.2 1.5 452 96 1.6 0.2
500 194 81 9.6 0.6 456 87 1.7 0.5
2,500 1,699 402 9.8 0.4 438 95 1.4 0.3
U1
10,000 7,358 1,956 9.8 0.7 487 74 1.3 0.2 w
20,000 11,220 5,183 9.9 0.4 478 75 1.3 0.2
50,000 42,547 14,128 9.7 0.7 440 92 1.2 0.4
100,000 68,322 28,924 9.8 0.6 518 82 1.4 0.3
a 10.8 ±condition factor,0.88 ±0.06.bMean (±SD)weight,11.2 ±1.1 g;length,0.5 cm;
Based on weight of paydirt added to each of ten replicate 1.9-L glass jars.CdBased on total residue for a 100-m1 grab sample taken immediately after the jar was inverted.
Based on total residue for a 100-m1 grab sample taken 30 min after the jar was inverted.
TABLE 14.Sealed jar bioassay:Effect of suspended organic overburden on tolerance to hypoxia and
time to hypoxic death for underyear1ing Arctic gray1inga acclimated to 15°C.
Overburden concentration Temperature at Time to death Residual oxygen at
(mg.L-1)death cot)(min)death (mg 02·L-1)
nomina1b initial final Mean SD Mean SD Mean SD
suspended suspended
residuec residued
0 <1 1 20.2 0.1 239 11 2.0 0.2
0 <1 2 20.3 0.1 227 40 2.0 0.3
100 120 43 20.3 0.1 209 44 2.1 0.3 VI.p.
1,000 786 347 20.3 0.1 189 22 2.3 0.4
5,000 4,123 832 20.3 0.1 203 16 1.8 0.3
10,000 7,870 941 20.4 0.1 187 35 2.1 0.6
20,000 12,870 1,027 20.3 0.1 175 36 2.1 0.4
50,000 23,200 2,723 20.0 0.1 136 24 2.3 0.6
a .
bMean (±SD)weight,10.3 ±1.1 g;length,9.9 ±0.5 cm condition factor,0.96 ±0.07.
Based on dry weight of overburden added to each of ten replicate l.9-L glass jars.ca:ased on total residue for a 100-ml grab sample taken immediately after the jar was inverted.
ased on total residue for a 100-ml grab sample taken 30 min after the jar was inverted.
r--,,)
_.....
.J
E--J [..~.~L ...J L J ))L..;j
TABLE 15.Sealed jar bioassay:Effect of pentachloropheno~on tolerance.to hypoxia
and time to hypoxic death for underyearling Arctic graylinga.acclimated to 15°C.
a Mean (±SD)weight,10.3 ±1.1 g;length,10.1 ±0.4 cm;condition factor,
0.98 ±0.07.
TABLE 16.Acute stress bioassay:Effect of suspended inorganic paydirt on blood sugar,hematocrit and leuco-
crit values for underyearling Arctic graylinga acclimated to 15°C.
Paydirt concentration Plasma glucose Hematocrit Leucocrit
(mg·L-I )(mg %)(%)(%)
nominalb initial final Mean SD Mean SD Mean SD
suspended suspended
residuec residued
0 (initial 5 8 105.8 23.7 32.4 1.4 1.18 0.22control)
0 (final 2 5 82.5 7.7 33.9 2.4 1.29 0.16control)
50 43 44 91.3 20.7 35.1 2.6 1.35 0.24
100 102 85 98.8 12.3 34.4 3.1 1.22 0.27 \JI
90.8 28.4 33.7 1.8 1.21 0.29 (J"I500281402
1,000 420 560 120.9 11.0 34.3 2.9 1.13 0.26
5,000 4,121 7,650 82.3 10.1 34.8 3.4 0.96 0.16
10,000 15,725 10,230 116.2 54.6 33.4 2.5 1.07 0.37
20,000 17,135 22,840 73.1 26.1 34.4 4.9 0.93 0.28
100,000 56,960 118,305 102.6 32.2 34.7 4.6 1.09 0.47
a
bMean (±SD)weight,3.8 ±0.7 g;length,7.9 ±0.6 cm;condition factor,0.76 ±0.05.
cBased on weight of paydirt added to a 50-L test volume.
Based on total residue for a 10o-L grab sample taken from centre of vessel at 0.5 h after
~ediment is added.
Based on total residue for a 100-ml grab sample taken from centre of vessel at end of test.
TABLE 17.Acute stress bioassay:Effect of suspended organic overburden on blood sugar,hemato-ocritand1eucocritvaluesforunderyear1ingArcticgray1ingaacclimatedto15 c.
Overburden concentration Plasma glucose Hematocrit Leucocrit
(mg·L-I )(mg %)(%)(%)
. 1
b final Mean SD Mean SD Mean SDnoml.na
suspended
residuec
0 (initial 3 67.4 5.7 31.0 1.6 1.25 0.34 VIcontrol)'"
0 (final 5 74.4 10.2 32.0 2.2 1.36 0.46control)
50 30 94.5 12.8 33.1 0.6 1.22 0.39
100 190 85.8 13.5 31.6 2.0 1.35 0.13
1,000 1,590 101.2 10.1 33.2 2.0 1.15 0.13
5,000 2,757 80.9 10'.4 32.8 2.1 1.15 0.14
10,000 4,696 103.3 28.0 31.4 2.5 0.95 0.29
20,000 12,296 88.2 21..9 31.3 1.6 0.94 0.33
~ean (±SD)weight,3.2 i:0.8 gj length,7.5 i:0.6 cm;condition factor,0.78 i:0.06.
bBased on dry weight of overburden added to test volume.
aBased on total residue for a lOO-r grab sample taken fro1ll.centre of vessel at end of test.
TABLE 18.Acute stress bioassay:Effect of pentachlorophenol on blood sugar,hemato-
crit and1eucocrit values for underyear1ing Arctic gray1inga acclimated to 15°C.
a Mean (±SD)weight,3.3 ±0.6 g;length,7.6 ±0.7 cm;condition factor,0.75 ±0.06 •
.'
r-J
TABLE 19.Summary of threshold-effect concentrations of paydirt or overburden suspensions causing acute re-
sponses for Arctic grayling.
Bioassay test
temperature tolerance
sealed jar bioassay
sealed jar bioassay
Acclimation
temperature
(OC)
15
15
15
15
Exposure
(h)
96
12
5
5
Response
decreased fish survival
decreased critical thermal maxima
increased (paydirt)or decreased
(overburden)time to death
increased residual oxygen
at death
paydirt
>100,000
100
(50-500)
4,407
(297-22,933)
>100,000
overburden
>50,000
8,471
(1,574->50,000)
161
(4,...615)
>50,000
1eucocrit stress test
blood sugar stress test
15
15
24
24
decreased 1eucocrit values
increased plasma glucose
values
51,651 5,843
(2,381->100,000)(2,092-29,107)
<50
LC50
temperature tolerance
sealed jar bioassay
sealed jar bioassay
1eucocrit stress testd
dbloodsugarstresstest
5
5
5
5
5
5
96
20
8
8
96
96
decreased fish survival
decreased critical thermal maxima
increased time to death
increased residual oxygen
at death
decreased 1eucocrit values
increased plasma glucose
values
>100,000
>50,000
>100,000
>100,000
C
C
e
e
e
e
e
e
~edian effective concentration causing a net significant response for 50%of fish (95%confidence interval
bin parentheses).
Median lethal concentration.
cUnab1e to calculate due to increased variance of data.
dNot conducted as a stress bioassay (values based on those for fish surviving a 96-h exposure).e .Not mea.sured.
Table 200 Water quality characteristics monitored at test site in Highet Creek and the control site in
Minto Creek during the fish enclosure tests,August and Septemeber,19820
range
Highet Creek Minto Creek
August 1982 September 1982 August 1982 September 1982
9.0 4.8 12.8 6.3
1.8 (9)2.7(7)0.7(7)1.3 (7)
7.0 -12.0 1.0 -9.0 12.0 -14.0 5.0 -7.0
11.0 12.6 10.2 10.2
0.7(9)0.9(7)0.7(7)0.5(7)
9.7 -11.5 9.5 -13.5 9.4 -11.0 10.0 -10.7
7.4 7.2 7.3 6.7
0.3(9)0.2 (7)0.2(7)0.2(7)0'a7.1 -7.9 6.9 -7.4 7.2 -7.5 6.5 -6.9
51 636 1.1 0.9
52 ~~O)483 (60)0.3(48)0.3(44)
3 -250 100 -2250 0.7 -1.8 0.5 -1.8
61 421 22 10
46 (78)257 (60)34(48)7 (44)
<20 -208 80 -1210 <20 -40 <5 -34
161 637 152
54 (78)354 (60)47 (48)
79 -294 189 -1900 122 -319
146 585 119
52 (78)342 (60)37 (48)
77 -270 171 -1800 92 -246
18.0 47 35
8.0 (78)20 (60)13 (48)
<10 -40 18 -110 19 -73
mean
SD2
range
mean
SD
range
SD
range
mean
SD
range
mean
SD
range
Statistic
pH
Variable
turbidity (FTU)
total residue (mg·L-I )
water temperature (OC)1
dissolved dxygen (mgoL-I )
total fixed residue (mg·L-I )·mean
SD
range
total volatile residue (mgoL-I)mean
SD
mean
SD
range
nonfi1trab1e residue (mg·L-I )mean
ITemperatures recorded by Birtwe11 et ale (1983)for the same August period were 6.0-9.5 in Highet Creek
and 13.0-14.5 in Minto Creek.
2Number in brackets indicates number of samples analysed.
..
r-1 r-:-;r--J r-J r-1 r-J r-J r-J r:-J''''c-J j r::J c-J c-J [""""'""]r-l rJ :-1 ~tT'J
[-]L J l.J .J L J I
L.J L..l ..J
TABLE 21.Hardness,alkalinity and metal contenta (mgoL-I·)determined for water samples b taken from
Highet,Minto and Mud creeks during the fish enclosure tests,August and September,1982.
Variable Highet Creek Minto Creek Mud Creek
August September August September September
EDTA hardness C 73-75 79.,...80 110-114 123 141
a1ka1ini ty C 50-52 51 100-104 112 120
arsenic (As)0.1-0.2 <0.05 0.01-0.07 <0.05 <0.05
boron (B)<0.001 <0.001 <0.001 <0.001 0.011
barium (Ba)0.047-0.049 0.041-0.049 0.066-0.069 0.068 0.094
cadmium (Cd)<0.002 <0.002 <0.002 <0.002 <0.002
chromium (Cr)<0.005 <0.005 <0.005 <0.005 <0.005
copper (Cu)<0.005 <0.005 <0.005 <0.005 <0.005
mercury (Hg)<0.0002 <0.0002 <0.0002 <0.0002 <0.0002
manganese (Mn)0.048-0.052 0.013-0.027 0.014-0.016 <0.001 <0.001 0\
~
nickel (Ni)<0.02 <0.02 <0.02 <0.02 <0.02
lead (Pb)<0.02 <0.02 <0.02 <0.02 <0.02
tin (Sb)<0.05 0.11-0.17 <0.05 <0.05 <0.05
strontium (Sr)0.12-0.13 0.14 0.21 0.23 0.20
zinc (Zn)0.05 0.02 0.02-0.03 0.02 0.01
aluminum (AI)0.2-0.3 0.1 <0.05-0.06 <0.05 <0.05
iron (Fe)0.3-0.5 0.1 0.4-0.5 0.4 <0.01
silicon (Si)4.2-4.4 4.3-4.4 2.9-3.0 3.2 2.4
calcium (Ca)23.0 25.4-26.0 31.3-32.4 36.1 41.4
magnesium (Mg)3.3-3.4 3.5-3.6 7.3-7.5 8.0 9.1
sodium (Na)1.6 1.9 1.8 2.1 1.4
br 0tal metal concentration,based on inductively coupled argon plasma spectrographic analysiso
4 samples were analysed for each trip and study site except Mud Creek where a single sample
was co11ec~ef 0
amg CaC03·L·0
-62 -
TABLE 22.Particle size distribution for suspended sediment sampled from
Highet Creek during August and September,1982.
Particle August 1982 suspensions September 1982 suspensions
si2:ea
weight cumulative weight cumulative.(Jm)(%)weight (%)(%)weight (%)
>400 0 0 0 0
>50 1.5 1.5 0.2 0.2
>25 54.7 56.2 61.0 61.2
>2 29.2 85.4 27.7 88.9
<2 14.6 100.0 11.1 100.0
a the pipet method (Anon.1975).Measured using
-
rL
[
[
[
[
[
[
[
"[
[
[
[
[
[
[
r~
I.~
TABLE 23.Percentage survival of underyear1ing Arctic grayling held in Highet Creek or Minto Creek for 4-5
days during August or September,1982.
Test site Test period No.of Source Length Weight Fish survival (%)
fish of fish (cm)a (g)a 24h 48h 72h 96h 120h
Highet Creek August 5-9 99 Minto Creek 5.3 1.3 100 100 100 100b
(0.7)(0.6)
Minto Creek August 5-9 92 Minto Creek 5.2 1.3 100 100 100 100b
(0.8)(0.5)
Highet Creek September 10-15 36 Minto Creek 7.4 3.6 100 100 100 100 100
(1.3)(1.9)
0'1
UJ
Highet Creek September 10-15 32 Mud Creek 6.5 2.4 97 97 84 84 84
(1.1)(1.7)
Minto Creek September 10-15 35 Minto Creek 8.1 4.5 100 100 100 100 100
(1.4)(2.3)
Minto Creek September 10-15 28 Mud Creek 6.5 2.3 100 100 100 100 100
(0.5)(0.7)
abMean (±SD)values,measured at the termination of the exposure period.
Experiment terminated at 96 h.
TABLE 2.4.Gill histopatho1ogiesa for underyear1ing Arctic grayling held in Minto Creek or Highet
Creek during September 1982.
Treatment Fish b Hyperplasiac Clubbingd Debris eHypertrophyParasites
no.
caged in Minto Creek 1 +H--1+-1+f -1+
for 4 days 2 -1+++-1+
3 -1++H--1++H-
4 +H--1+-1+-1+
5 -1+-1++-1+
'"~
caged in Highet Creek 6 +H--1+-1+++H-I
for 4 days 7 -1+-1+-1++-1+
8 -1+-1++-1+-1+
9 -1+-1+-1++-1+
10 +H--1+++-1+
seined from Minto 11 ++++
Creek 12 +++
13 -1++
apositive values are based on a scale of 1 to 4,where +=slight;-1+=moderate;+H-marked;
band -1+-1+=very marked.
Increase in cellular size.
~Increase in cellular number.
Thickening of distal ends of lamellae.
;Tentative1y identified as monogenetic trematodes.
Not evident.
..
1'""---'
l.J
·-1
,
I
TABLE 25.Mean (±SD)biological characteristics of underyear1ing Arctic grayling sampled from cages or directly from
creeks during August and September,1982.
No.(n)and source Date Treatment Length Weight Condition Hematocrit Plasma
of fish sampled (cm)(g)factor (%)glucose
(K)(mg %)
Mud Creek (19)09/08/82 seined from creek 5.9±0.6 1.9±0.5 0.88±0.06 43.6±4.9 63.9±8.9
Minto Creek (20)10/08/82 caged in Minto Creek 6.0±0.5 1.7±0.5 0.76±0.08 46.8±4.3 60.7±9.5
for 4 days
Minto Creek (20)10/08/82 caged in Highet Creek 6.1±0.6 1.8±0.5 0.81±0.07 46.1±5.6 81.2±8.8
for 4 days
Minto Creek (30)14/09/82 seined from creek 7.8±1.0 4.2±1.7 0.86±0.08 44.7±4.3 95.2±19.1 c:"\
Mud Creek (10)15/09/82
\...'1
caged in Minto Creek 6.7±0.5 2.4±0.6 0.79±0.07 46.1±4.5 64.1±12.0
for 4 days
Minto Creek (10)15/09/82 caged in Minto Creek 8.9±1.7 5.9±3.0 0.76±0.05 55.6±2.5 132.4±54.9
for 4 days
Mud Creek (10)15/09/82 caged in Highet Creek 7.4±1.5 3.6±2.8 0.77±0.03 50.6±3.7 159.3±69.2
for 4 days
Minto Creek (10)15/09/82 caged in Highet Creek 9.1±0.6 6.3±1.5 0.82±0.05 52.6±4.3 276.4±141.4
for 4 days
E u
ID ..,
l
i
E u
on
.0
N
I
I
T
....
67
PUMP
(10 L·min-1)
FIG. 1. Illustration of recycle test
BOTTOM OF
NYLON MESH
CAGE INSERT
tanks.
75mm
RED BLOOD CELLS
------SEA LANT
~--BUFFY LAYER (WHITE BLOOD CELLS
AND THROMBOCYTES)
LEUCOCRIT (%)=HEIGHT OF BUFFY LAYER X 100
HEIGHT OF TOTAL BLOOD VOLUME
PLASMA OR SERUM
HEIGHT OF PACKED CELLSHEMATOCRIT(%)=--------------X 100
HEIGHT OF TOTAL BLOOD VOLUME
TOTAL
PACKED CELLS-
FIG.2.Illustration of derivation of hematocrit and leucocrit values from
a centrifuged blood sample within a heparinized glass capillary tube.
TOTAL
BLOOD VOLUME-
Enclosure
Settling Ponds
t.:.-=-:..O====-2 Km
FIG.3.Map of site for in-situ caged fish studies.
['
[
-73 -
heavy gauge
wire hook
draw string
---.----ttt---------,~~
melal post
4cm diameter
,-'
L.
[
[
[
[
[
[
[
[
1.8m
O.84m
O.30m
--
--~-''-'--''1 wire ring IW
.'".....
water depth
=O.5m
r~
L.
[
[.
['.
,
l
PLAN VIEW
posf'---__iIIIi
opening
fIG.4.Schematic drawing of net enclosures
for in-situ caged fish studies.
-75 -
FIG. 5. Study site at Minto Creek. Fish enclosures are
shown in-situ.
FIG. 6. Study site at Highet Creek. Fish enclosures are
shown in-situ.
FIG.7.Relationship of total reSidue,nonfiltrable residue and turbidity
for suspensions of paydirt sediment in freshwater.
-77 -
-i
C
::0m
o
-i-<-"-i
C-
00
0.000
.000
00.000
200
50
2.000
500
20.000
~.ooo
~o.ooo
0--0 TOTAL RESIDUE
.---.NONF ILTRABLE RES I DUE
-------TURBIDITY
20
5
o
20 50 100 200 ~OO 1.000 2.000 ~.ooo 10.000 20.000 50.000 100.000
NOMINAL PAYDIRT CONCENTRATION <mg·t l
)
o
~-1
...
,r
//
.~~1
,
14"/
~////
/V I
I'/
r
.F /
.J ;I /
//
oJ V"/:l:'"'"I
II /
/1 .:/
,,'/./
/~~
OI!~..-..;~~
~
"
50
100
200
~oo
20
5
o
1.000
2.000
~.ooo
10.000
~o.ooo
100.000
-'j'20.000
:...J•CI-E
T...J -•WCI
E :::>-0
W C/)
:::>w
0 a:::
C/)wwa:::...Jm
...J <{
~a:::
~0....I.L.
Z
0
Z
rL
[
c-
[~
L
[
[
[
[
[
[
n
c
o
"c
c
c
[
[
FIG.8.Relationship of total residue,nonfiltrable residue and turbidity
for suspension~of overburden sediment in freshwater.
-79 -
-'TI
c!-
00
0.000
200
5.000
50
20.000
-I
C
2.000 ::0
CD
.000 0
~
100.000
0---0 TOTAL RESIDUE
e---e NONFILTRABLE RESIDUE
• •TURBIDITY
20
5
o
20 50 100 200 500 1.000 2,000 5,000 10,000 20,000 50,000 100,000
NOMINAL OVERBURDEN CONCENTRATION <mge[l)
i\
/
/
~'/I
I /
"/
/1/
7 /
/.,/~
I
,/
(~/
./v",;/
~~/A',"
"f'.I
"/
"/
I'.//
"///
I''/"~""..
~,/
"
50
20
5
00
100
200
500
1.000
5.000
2.000
10,000
20.000
50.000
100.000
-I...J
e
01-E~-e UJ01
E ::>-0
UJ en
UJ::>0:0
CJ)UJ
UJ ..J
0:m
..J <t
0:~~0 iL:F-Z
0
Z
[
['
[~
[
[
[
[
c
c
'"[
.>
C
C
[
[
[
[
c-
[~
[
I...J 10,000 10,000 mg'l-l•0-0'0-A>-D----~0
E -0=-
1J.J:::>
5,000 o3'g'l-ICI0-.-..0-J'~Cf)~
1J.J
0:::
...J
j:!
0 1,000r-
[
[
[
[
[
[
D
c
[
[
100,000
100
-81 -
t:'100,00~---------------eo-----o-_----=<>=<>0-__;...----=-e>=
[
[
o 0.5
••I ....__-'-L.'L.'.....'.T
5 24 48 72 96
TIME (h)
[
L-
[-
l
FIG.9.Illustration of the stability of differing concentra-
tions of suspended paydirt fines within recycle test tanks
during a 96-h bioassay.
FIG.10.Relationship of concentration of suspended inorganic paydirt to
critical thermal maxima for underyear1ing Arctic grayling acclimated to 15°C.
!I I !I I "I , I ,!!"
Note:Points represent mean;
bars,95%confidence interval
for 10 fish.
!!!!I.II
50 100 1,000 10,000 100,000
NOMINAL PAYDIRT CONCENTRATION (mg-L-')
I !!!!!!!I
29.0
test test----28.0 I 2 I 2
On 2 Q test-----I 2
:0 :0 :0 ~2 Q Q .027.0
~Q
26.0
-83 -
23.0
:r:
~wo
~
W
0::
:::>~25.0
0::
Wa..r5 24.0
I-
-0 0-
[
[
[
[
[
[
[
c
u
...c
[
F...•.U
[
[
[
[
[-
[.
[
28.0 :0:2-2 2 Q £oU-
J:27.0 ""~2~control
w
0
~26.0
w
Ci:Note:Points represent mean;::::>25.0~bars,95%confidence interval
Ci:for 10 fish.
wa..24.0~w
I-
-85 -
!! I !!'"!!! !!!"I !!I ,!"
a.........,'1 1111,,1,
50 100 1,000 10,000
NOMINAL OVERBURDEN CONCENTRATION
(dry weight basis)
23.0
29.0
[
[
['
[
[
[
[
[
c
...
[
[
[j
[
[
r~
L FIG.11.Relationship of concentration of suspended organic overburden to
critical thermal maxima for underyearling Arctic grayling acclimated to 15°C.
[
[-
[-
[
FIG.12.Relationship of concentration of suspended inorganic paydirt to
critical thermal maxima for underyear1ing Arctic grayling acclimated to SoC.
-87 -
I I I !I I "!!! !!!d
f
! !!! !I!I!! I I!!!I
Note:Points represent mean;
bars,95%confidence interval
for 10 fish.
50 100 1,000 10,000 100,000
NOMINAL PAYDIRT CONCENTRATION (mg-L-1)
I
controls
I
o
28.0
29.0
23.0
:::r:~27.0
wo
~26.0
w
0:
::::>~25.0
0:
Wa..
~24.0w
I-
-oU-
[
[-
r~
[
[
[
[
[
[
...c
[
G.·.•.LJ
[
[
[
[
[-
[-
[
-89 -
C 280 clntro,s
[
[
['
n
[
[
[
n
l
360
340
320
300
Note:Points represent mean;
bars,95%confidence interval
for 10 fish.
...
9
9 ,
E-
I 260~wo
o 240
I-
w
~220
I-
200
180
160
100,000
I I I I I !"I !!!!!"!!!!!!d
o
___-.,.,"!II!!!I
J
50 100 1,000 10,000
NOMINAL PAYDIRT CONCENTRATION (mg·C l )
FIG.13.Relationship of concentration of inorganic paydirt to time to
death in sealed jar bioassays for underyear1ing Arctic grayling acclim-
ated to 15°C and tested at 20°C.
-91 -
Note:Points represent mean;
bars,95%confidence interval
for 10 fish.2.4
2.5
2.3
-T..J
2.2e --controlsC'
/E-
z 2.1lLJ
(!)>-x
0
2.0
0
lLJ>..J
0 1.9CJ)
CJ)
0
..J 1.8<{
::>
0
CJ)
lLJ 1.7a:::
[
[
[,
c
[
[
c
c
o
c~
.....i
50 100 1,000 10,000
NOMINAL PAYDIRT CONCENTRATION (mgeL-1)
1.6
1.5 I !!I I !I II !!!I!,Ii I I I I!!!I ! !! ! !",
100,000
FIG.14.Relationship of concentration of inorganic paydirt to tolerance
to hypoxia in sealed jar bioassays for underyearling Arctic grayling ac-
climated to lSoC and tested at 20°C.
FIG.15.Relationship of concentration of inorganic paydirt to time to
death in sealed jar bioassays for underyearling Arctic grayling acclim-
ated to sOe and tested at lOoe.
-93 -
!I !I !!.I!I I !I I "!I I I I "I
Note:Points represent mean;
bars,95%confidence interval
for 10 fish.
50 100 1,000 10,000 100,000
NOMINAL PAYDIRT CONCENTRATION (mg·C>
I I ! !!!!d
controls
I
360
560
540
380
420
580
400
600
520-c:
E-500
J:
~
L1J 4800
0t-
L1J 460
~
t-
440
[
['
[
[
[
[
[
[
c.
[
[
E
[
[
[
[
l-
[.
[
FIG.16.Relationship of concentration of inorganic paydirt to tolerance
to hypoxia in sealed jar bioassays for underyearling Arctic grayling ac-
climated to 5°C and tested at lODe.
50 100 1,000 10,000
NOMINAL PAYDIRT CONCENTRATION (mg-L 1
)
100,000
I !!,.!!"
Note:Points represent mean;
bars,95%confidence interval
for 10 fish.
I I I !II"
-95 -
!!I I I!,II!I !! !"I
controls
I
1.00
1.80
1.90
0.80
0.90
2.00
-1.70~•0'
E.....,
z 1.60
lJJ
(!)
~
X 1.500
c
lJJ
~1.400
(J)
(J)
c
1.30
...J«::>c
(J)1.20w
0::
1.10
[
[,
[
[
[
[
[
c
[
.#
[
[
[
[
[
[
[
[-
[~
l
[
[
[
I'
L
[
[
[
[
[
..
[
C
C
[
controls
260 _1_
240 2
220-c
E-I 200
~w
o 180
o
~
~160
~
140
120
-97 -
Note:Points represent mean;
bars,95%confidence interval
for 10 fish.
[
[.
[-
[
1001-1.,,'1-'.....1....'.'...Io'.'.l.I''u.I_...L......I.'...L.'...I.'...I.''''''''.I.'l.L"_.....I.__,I.o.,I,I...l'...l'I.I'..'.I.I"_.....I._...'...l'-'-'...''..,.'.w'Io501001,000 10,000 100,000
NOMINAL OVERBURDEN CONCENTRATION (mg-["I)
(dry weight basis)
FIG.17.Relationship of concentration of organic overburden to time to death
in sealed jar bioassays for underyearling Arctic grayling acclimated to lSoC
and tested at 20°C.
FIG.18.Relationship of concentration of organic overburden to tolerance
to hypoxia in sealed jar bioassays for underyearling Arctic grayling acclim-o 0atedto15Candtestedat20 C.
!!! !!!d
100,000
(mg·L-')
! !!!!I "!! !!!!d
Note:Points represent mean;
bars,95%confidence interval
for 10 fish.
50 100 1,000 10,000
NOMINAL OVERBURDEN CONCENTRATION
(dry weight basis)
controls
_I
1.9
1.6
1.8
1.7
1.5
..J 2.0
<{
::>o
(f)wa::
•
C'
E
2.6
-99-
2.7
2.5
2.8
z 2.3w
(!)
>-X
o 2.2
ow
~o 2.1
(f)
(f)
o
......
-I..J 2.4
.J
-101 -
1.7
final
control
I
1.4
Note:Points represent mean;
bars,95%confidence interval
for 10 fish.
1.5
...."""""1')1"'-10,.....,..,j,'..I'..,j,'.I.'.1.1,,_......1..0.-.'......100'.'.1.'.',I"I"...I_......_~,..,j,'.....1..'1-'I.l''.I.'....1_....".....,j'.....'..,j1..,j'o.l'.I.'..'I
0.6 a r 50 100 1,000 10,000 100,000
NOMINAL PAYDIRT CONCENTRATION (mg"C')
1.6
0.7
1.8
0.9
0.8
FIG.19.Relationship of concentration of suspended inorganic paydirt to
blood leucocrit values for underyearling Arctic grayling acclimated to
ISoC and exposed to sediment for 24 h.
'0 1.30"-
I-
0:::1.2u
0u
::::>w
..J 1.1
-initial
control
1.0
[
['.--
[.
[
[
[
[
['
[
[
[
[
[
[
..c
[
[
[
[
FIG.20.Relationship of concentration of suspended organic overburden
to blood leucocrit values for underyearling Arctic grayling acclimated
to 15°C and exposed to sediment for 24 h.
!!I !!'"II
100,000
(mg-L-1)
Note:Points represent mean;
bars,95%confidence interval
for 10 fish.-final
control
.1 ..IinitiO
control
_~II "",,1 "I'!!,1 I 11!!,d
0.50 a i 50 100 1,000 10,000
NOMINAL OVERBURDEN CONCENTRATION
(dry weight basis)
0.90
0.80
1.20
1.30
0.60
0.70
lAO
1.50
1.60
1.80
-103 -
1.70
.-1.10
0::uou::::>1.00
UJ
--l
-
"*'-
[
[,
[
[
[
[
[
[
n
.-c
[
c
[
[
[
[
[.
[~
[
FIG.21.Relationship of concentration of suspended inorganic paydirt to
blood sugar values for underyearling Arctic grayling acclimated to lSoC
and exposed to sediment for 24 h.
100,000
!I ! !!I!I
-105 -
Note:Points represent mean;
bars,95%confidence interval
for 10 fish.
L..-.L.....II!!! !!!"!!!!,!,I !!f !!!!,
50 0 J 50 100 1,000 10,000
NOMINAL PAYDIRT CONCENTRATION (mg-L-1)
60
140
160
150
[
[
['
[
[
[
[
C
0:.'·.~
~
C
t>
[
C
[
[
[
[
[.
C·
[
!!!!!"I
100,000
-I(mg-L )
I I !I I II I
-107 -
Note:Points represent mean;
bars,95%confidence interval
for 10 fish.
50 100 1,000 10,000
NOMINAL OVERBURDEN CONCENTRATION
(dry weight basis)
50
140
150
FIG.22.Relationship of concentration of suspended organic overburden to
blood sugar values for underyearling Arctic grayling acclimated to 15°C and
exposed to sediment for 24 h.
130
-a-e
0'120
E-
lLJen 1100u:::>
...J
c:>100
<{
~en
<{90...Ja..
80
70 ~-finalcontrol
-initial
control
60
[
[
[;
[
[
[
[
[
D
...
[
[
L
[
[
[
L
L~
[.
[
FIG.23.Relationship of concentration of suspended inorganic paydirt to
blood sugar values for underyearling Arctic grayling acclimated to 5°C and
exposed to sediment for 96 h.
50 100 1,000 10,000
NOMINAL PAYDIRT CONCENTRATION (mg·L-1)
100,000
I I!'I "II I I I!'"I I I I 1,,1
-109 -
Note:Points represent mean;
bars,95%confidence interval
for 10 fish.
I !I I I I "J20
220
200
180
-~1600
0'
E.....,
UJ 140C/)
0u
:::>-l 120<!>
«
:!:
C/)100«
-la.
80
60 f-contro,
40
[
[
-4[
[
[
[
[
[
[
,..
[
[
c
[
[
[
l
['
u·
[.
[
1100
1000
800
600
~:::>
-l-eu.
400
200
o
TURBIDITY (FTU)
TOTAL RESIDUE (mg-L-1)
,.-......
•_--~;......_...•It
-_-_.,..
..............""',,...
23301230
05/08/82
II 30
06/081 82
2330 1130
07 1 08 1 82
TIM E (h)
2330 1130
08 1 08 1 82
2330 1130
09 1 08 1 82
2130 HOUR
DATE
FIG.24.Illustration of concentration of suspended sediment (total residue)
and turbidity within cages held in Highet Creek during August 1982.
[
."
2300
2000
1500
1000
............
--------.TURBIDITY (nUl
TOTAL RESIDUE (mg'L-I l
....,.
"',,.
'.'
II
I
I
I
I
I
I
I
I
I
I
I
I
I "
I ,.'"I I •
I ,•
I "\I I .""
1 ',Ii ...·
I,'
\,
I
I
I
I
I
I
I
I
I
I,I,,.._----
.'
o
1720 2320
10/09182
1120
11/09/82
2320 1120
12/09/82
2320 1120
13/09/82
TIM E (hl
2320 1120
14/09/82
23 20 1120 1920
15/09/82
HOUR
DATE
FIG.25.Illustration of concentration of suspended sediment (total residue)
and turbidity within cages held in Highet Creek during September 1982.
-11 5 -
FIG. 26. Gill filaments of underyearling Arctic grayling
captured from Minto Creek during September 1982. Note
normal appearance of secondary lamellae (a). 300X.
~
c
I
FIG.27. Gill filaments of underyearling Arctic grayling
captured from Minto Creek and held in a cage within Minto
Creek for 5 days during September 1982. Note moderate
hypertrophy (increase in cell size) and hyperplasia (in-
crease in cell numbers) of lamellar epithelium (b), and
presence of large numbers of ectoparasites (c). 300X.
-117 -
APPENDIX 1.Summary of the aquatic biophysical characteristics for the Highet Creek
and Minto Creek caged fish sites during August and September 1982.
Site
[
[
[
v
[
p
[
[
L~
I'
L~
IL~
[
Variable
riparian vegetation
channel cover
biota abundance
predominant flow
channel
channel width (m)
mid-channel depth (m)
debris abundance
bed material
Type
coniferous
deciduous
underbrush
ground
crown
overhang
aquatic plants
stream
invertebrates
algae
August
September
Minto Creek
very few Picea
very few
dense Salix and
Alnus
continuous cover
of grasses and
berries
nil
low/moderate
moderate
moderate
moderate
glide
7.6
0.4
moderate
60%fines,40%gravel
0.69a ,0.43b
0.23d
Highet Creek
several patches of
Picea
several (Populus
tremuloids,
P.trichocarpa,
and Betula)
continuous cover of
Salix and Alnus
few patches of
grasses and
mosses
moderate
moderate
nil
low
low
riffle backwater
3.0
0.5
low
100%fines
at surface
0.32c
0.22d
[.
[
~DiScharge gauged on August 5,1982.
Discharge gauged on August 10,1982.
~DiScharge gauged on August 7,1982.
Discharge gauged on September 13,1982.
'",r;r-l r-l r-:i r-J r-J r-J c--:J r-TI {~.r-J t\[T"'j L'1 r-J r-J r-l ["'""""l r-7 ~rJ
~I ~l _'
,...----,, I
APPENDIX 3.Physical/chemical characteristics during 4-day survival test 0with15 C-acc1imated
underyear1ing Arctic grayling exposed to organic overburden suspensions.
Time Variable Nominal overburden concentration
(h)(mg'L-l)
0 50 100 1 t OOO 5 t OOO 10 t ODO 50 t OOO
temperature (OC)15.1 15.0 15.0 15.0 15.1 15.1 15.0
oxygen (mg'L-1 )9.2 9.3 9.2 9.2 9.2 9.3 9.2
0 pH 6.9 6.8 6.9 6.8 6.8 6.8 6.9
conductanced 15 15 15 15 20 25 30
temperature 15.4 15.1 15.3 15.3 15.3 15.2 15.3
oxygen 9.1 9.3 9.2 9.2 9.3 9.1 9.3
24 pH 6.9 7.0 6.9 6.9 6.9 6.8
6.9
conductance 18 18 16 20 25 30 35
I-'
I-'
15.2 15.2 15.1 15.2 15.1 15.1 15.2 \0temperature
9.3 9.3 9.2 9.2 9.2 9.3 9.3 If.)oxygen ;/.~.
48 pH 6.9 7.0 6.9 6.0 7.0 6.9 6.9
conductance 20 20
20 20 25 35 40
temperature 15.1 15.3 15.1 15.2 15.1 15.1 15.2
oxygen 9.2 -9.1 9.2 9.2 9.1 9.2 9.2
72 pH 6.8 6.9 6.9 6.9 6.8 6.9 6.9
conductance 20 20
20 20 25 35 35
temperature 15.0 15.1 15.0 15.0 15.1 15.1 15.0
oxygen 9.3 9.2 9.3 9.3 9.2 9.2 9.2
96 pH 6.8 6.8 6.9 -6.9 6.8 6.8 6~9
conductance 20 20 20 25 25 30 35
d llmho'cm-1.
APPENDIX 4.Physica1(ch eIlJ.ica.1 cnara.cteri~tic~during 4...day l;lurviva1 test wtth 5 0 C....acclimated
underyearlingArctic grayling e:8:l?osedto inorganic paydirtsuspensions.
....
Time Variable .Nominalpaydirt concentration
(h)(ms'L-1 )
0 1,000 5,000 10,000 20,000 100,000
temperature (OC)5.0 5.1 5.0 5.0 5.1 5.0
0 oxygen (mg·L-1 )10.8 10.8 10.9 10.7 10.8 10.8
pH 6.8 6.7 6.7 6.7 6.6 6.7
conductancea 18 18 20 30 20 40
temperature 5.2 5.2 5.1 5.2 5.0 5.2
24 oxygen 10.6 10.6 10.5 10.7 10.7 10.6
pH 6.7 6.7 6.8 6.7 6.6 6.7
conductance 18 1~20 30 25 50 ~
N
0temperature4.7 4.4 4.9 4.3 4.6 4.2
48 oxygen 10.8 10.8 10.9 10.7 10.8 10.9
pH 6.8 6.9 6.8 6.8 6.8 6.8
conductance 15 17 18 23 32 35
temperature 5.3 5.0 5.1 5.0 4.9 4.7
72 oxygen 10.9 10.7 10.8 10.8 10.8 10.8
pH 6.7 6.6 6.6 6.7 6.7 6.7
conductance 15 18 22 25 32 37
temperature 5.1 5.0 5.0 5.2 5.3 4.9
96 oxygen 10.8 10.8 10.9 10.9 10.6 .10.8
pH 6.7 6.7 6.5 6.5 6.6 6.6
conductance 18 21 22 29 32 40
a -1llmho·cm •
-121 -
APPENDIX 5.Residue and turbidity values within a cage held in Highet Creek during
--<'the August 1982 in-situ fish survival test.
\Date Time Sample Total Total Total Non-Turbidity
~\"(h)noo residue fixed volatile filtrable (FTll)
(mg °L -1)residue resi~ye resid~r
(mg'L-1)(mgoL )(mgoL )
05/08/82 1330 EX 1 335 279 56 210 180
1430 EX 2 435 411 24 347 240
1530 EX 3 416 388 28 314 340
1630 EX 4 391 369 22 310 380
1730 EX 5 409 385 24 318 380
[1830 EX 6 381 355 26 29B.360
1930 EX 7 360 339 21 262 320
2030 EX 8 317 304 13 194 280
2130 EX 9 309 290 19 214 260
2230 EX 10 290 277 13 200 225
2330 EX 11 308 285 23 206 250
06/08/82 0030 EX 12 333 310 23 230 295
[0130 EX 13 335 307 28 242 310
0230 EX 14 349 307 42 250 325
fl 0330 EX 15 341 304 37 230 300
P 0430 EX 16 341 313 28 206 290
l 0530 EX 17 350 319 31 262 310
{0630 EX 18 360 333 27 298 310
[0730 EX 19 382 344 38 246 '.300
0830 EX 20 322 291 31 166 280
0930 EX 21 285 265 20 184 190
1030 EX 22 222 198 24 134 130
L 1130 EX 23 208 197 11 104 115
1230 EX 24 365 319 46 244 290
1330 EX 25 466 431 35 392 500
[1430 EX 26 713 668 45 608 950
1530 EX 27 584 543 41 486 700
1630 EX 28 510 482 28 424 700
[1730a EX 29 292 259 33 180 165
1830 EX 30 283 270 13 164 170
1930 EX 31 JJ
2030 EX 32 214 201 13 128 120r2130EX33
L.]2230 EX 34 294 260 34 208 250
2330 EX 35
[07/08/82 0030 EX 36 238 220 18 138 185
0130 EX 37
0230 EX 38 215 203 12 126 150
r--0330 EX 39
0430 EX 40 161 148 13 54 60L'"0530 EX 41
[~
[
-122 -[
r',.~,
APPENDIX 5 (cont.)(,
(>~~
Sample Total Total Total Non-Turbidity LDateTime
(h)no.residue,fixed volatile filtrable (FTU)r(I!lg'.~-1),residue resi~ye residue L(mg.L -1)(mg·L )(mg.L -1)
07/08/82 0630 EX 42 192 '171 21 60 55 [(cont.)0730 EX 43
0830 EX 44 218 187 31 108 65
0930 EX 45 [1030 EX 46 185 173 12 _84 45
1130 EX 47
1230 EX 48 <L23 112 11 16 17 [1330 EX 49 --
1430 EX 50 96 89 <10 <20 4.8
1530 EX 51 [1630 EX 52 109 86 23 <20 4.6
1730 EX 53
1830 EX 54 118 118 <10 '<20 15
1930 EX 55 35 [2030 EX 56 186 172 14 70 44
2130 EX 57 q
2230 "EX 58 202 195 <10 92 45 r2330'EX 59 U
08/08/82 0030 EX 60 190 195 <10 94 85 '-",
0130 EX 61 [0230 EX 62 208 202 <10 92 80
0330 EX 63
0430 EX 64 168 174 <10 74 65 [0530 EX 65
0630 EX 66 198 183 15 94 54
0730 EX 67
0830 EX 68 157 152 40 38 43 [0930 EX 69 36
1030 EX 70
1130 EX 71 L1230EX72918840<20 6.8
1330 EX 73
1430 EX 74 92 80 12 <20 3.0 [1530 EX 75
1630 EX 76 101 79 22 <20 3.6
1730 EX 77
1830 EX 78 79 79 <10 i.20 3.8 [1930 EX 79
2030 EX 80 105 96 <10 20 20
2130 EX 81 f'2230 EX 82 154 157 <10 50 26 I?L-"2330 EX 83
T'
"L
[
-123 -
-.
APPENDIX 5 (cant.)
-~~
Date Time Sample Total Total Total Non-Turbidity
'(h)noo residue fixed.,volatile filtrable (FTU)
(mgOL-1)residue resi~'fe residue
(mgoL -1)(mg °L )(mg °L -1)
09/08/82 0030 EX 84 149 159 <10 34 38
0130 EX 85
I'0230 EX 86·184 165 19 38 38
Lo 0330 EX 87 -
0430 EX 88 184 166 18 68 55
0530 EX 89
[0630 EX 90 178 157 21 72 55
0730 EX 91
0830 EX 92 197 176 21 82 55
[0930 EX 93
1030 EX 94 147 136 11 40 53
1130 EX 95
[1230 EX 96 112 105 <10 <20 20
1330 EX 97
1430 EX 98 115 97 18 <20 8 0 0
p 1530 EX 99
[1630 EX 100 117 92 25 <20 8.0
1730 EX 101
I 1830 EX 102 112 90 22 20 5.0
[1930 EX 103
2030 EX 104 111 87 24 <20 7.5
2130 EX 105
[
2230 EX 106 169 131 38 58 30
2330 EX 107
10/08/82 0030 EX 108
[0130 EX 109
0230 EX 110 199 172 27 88 50
0330 EX 111
0430 EX 112 173 152 21 92 65
[0530 EX 113
0630 EX 114 190 168 22 66 68
0730 EX 115
[0830 EX 116 230 211 19 58 85
0930 EX 117
1030 EX 118 147 125 22 34 25
[1130 EX 119
1230 EX 120 108 77 31 <20 11
1330 EX 121
1430 EX 122 106 89 17 <20 14
1'--1530 EX 123
L<"1630 EX 124 106 97 <10 28 31
[,..,.
[
-124 -[
APPENDIX 5 (cant.)[
~Fish placed in cages.
Not analysed °
Date Time Sample Total Total Total Non-Turbidity
(h)no.residue fixed volatile filtrable (FTU)
(mgOL -1)residue resi~1fe residue
(mg °L -1)(mg·L )(mg.L-1)
10/08/82 1730 EX 125
(cant.)1830 EX 126 107 90 17 <20 15
1930 EX 127
2030 EX 128 142 126 16 54 35
2130 EX 129
2230 EX 130 142 130 12 54 30
=======================================================l~
[
[
[
[
[
[
o
[
(~
C
[
[
[
[
[
[
-125 -
-,
"
APPENDIX 6.Residue and turbidity values within a cage held in Highet Creek duripg
-,)the September 1982 in-situ fish survival test.
,j
Date Time Sample Total Total Total Non-Turbidity
(h)no.residue 'fued volatile filtrable (FTT])
(mg·L-1 )"residue residue residue
(mgoL-1 )(mg·L-1 )(mg.L -1)
10/09/82 1530 EX 1 504 471 33 396 350
1630 EX 2 -b
1730a EX 3 429 404 25 308 320
1830 EX 4
1930 EX 5 384 360 24 270 270
2030 EX 6
2130 EX 7 260 241 19 144 150
2230 EX 8
2330 EX 9 333 307 26 236 210
11/09/82 0030 EX 10
~0130 EX 11 321 295 26 214 220
0230 EX 12",0330 EX 13 329 299 30 226 230
0430 EX 14
0530 EX 15 454 419 35 336 370
9 0630 EX 16
0730 EX 17 492 452 40 326 420
L 0830 EX 18
0930 EX 19
1030 EX 20
1130 EX 21 .;,;.-
1230 EX 22 373 340 33 108 245
1330 EX 23 292 262 30 222 150
1430 EX 24
1530 EX 25 600 556 44 404 410
1630 EX 26
1730 EX 27 599 550 49 484 570
-~1830 EX 28
1930 EX 29 592 545 47 470 510
2030 EX 30
L.J 2130 EX 31 819 754 65 700 1000
2230 EX 32
2330 EX 33 724 671 53 610 820
12/09/82 0030 EX 34
0130 EX 35 629 582 47 490 750
l~"0230 EX 36
0330 EX 37 494 454 40 384 460
0430 EX 38
I'0530 EX 39 688 635 53 558 720
i 0630 EX 40L......,~
0730 EX 41 492 463 29 358 400
[~0830 EX 42
[
-127 -
-129 -
APPENDIX 7 (cont.)
=',J
Date Time Sample Total Total Total Non-Turbidity
(h)no.residue fixed volatile filtrable (FTU)
(mg ·L:"l)residu~resi~ye resid~r
(mg.L-1)(mg·L )(mg·L )
08/08/82 0820 43
(cont.)0920 44 122 101 21 22 1.3
,.-,1020 45
1120 46 130 101 29 20 0.8
1220 47
1320 48 139 115 24 20 1.4[1420 49
1520 50 128 106 22 40 1.6
1620 51
[1720 52 126 95 31 <20 1.3
1820 53
1920 54 149 117 32 <20 1.1
[2020 55 -
2120 56 148 115 33 <20 1.1
222.0 57
•2320 58 145 114 31 <20 1.1
[09/08/82 0020 59
r 0120 60 148 116 32 <-20 1.1
0220 61
[0320 62 141 119 22 <20 0.8
0420 63
0520 64 141 121 20 <20 0.7
C 0620 65
0720 66 147 113 34 <20 0.8
0820 67
[0920 68 152 114 38 <20 1.4
1020 69
~)1120 70 149 101 48 24 1.1
1220 71
[1320 72 146 109 37 24 1.3
1420 73
1520 74 141 106 35 <20 1.3
[1620 75
1720 76
1820 77
L 1920 78 131 95 36 <20 1.3
2020 79
2120 80 135 96 39 <20 1.1
2220 81
[-2320 82
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-130 -
APPENDIX 7 (cant.)
Date Time Sample Total Tot.a1 Total Non-Turbidity
(h)no"residue fixed volatile filtrable (FTU)
(mg"L-1)residue resi~'te resid~r
(mg"L '-1)(mg"L )(mg"L )
10/08/82 0020 83
0120 84 133 98 35 <20 1.1
0220 85
0320 86 130 96 34 22 1.1
0420 87
0520 88 137 105 32 24 1.1
0620 89
0720 90 "154 104 50 24 1.6
0820 91
0920 92 153 110 43 <20 1.6
1020 93
1120 94 147 100 47 <20 1.2
1220 95
1320 96 130 100 30 <20 1.2
1420 97
1520 98 144 114 30 <20 1.2
1620 99
1720 100 141 113 28 <20 1.8
:~Fish placed in cages.
Not analysed"
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APPENDIX 8 (cant.)L
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Date Time Sample Non-Turbidity L.
(h)no.filtrable (FTU)
residue [(mgoL-1 )
12/09/82 1230 43 6 0.8 [(cant.)1330 44
1430 45 14 0.9
1530 46 [1630 47 0.9
1730 48 <5
1830 49 0.9 [1930 50 5
2030 51 16 1.5
2130 52
2230 53 <5 0.8 C23305412
13/09/82 0030 55 1.5
0130 56 C0230570.6
0330 58
0430 59 1.2 t0530608
0630 61 to-
0730 62 0.6 [108306380.8
0930 64 <0.5 Jj
1030 65
1130 66 <5 [1230 67 10 10 "
1330 68
1430 69 <5 0.9 [1530 70
1630 71 <5 1.0
1730 72
D183073<5 1.0
1930 74 <5
2030 75 0.7
2130 76 n
2230 77 <5 0.8 U
2330 78
14/09/82 0030 79 <5 0.8 U0130806
0230 81 0.6
0330 82 fi043083e-:.-J
0530 84
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-133 "-
APPENDIX 8 (cant.)
.Date Time Sample.Non-Turbidity
(h)no.filtrable (FTU)
residue
(mgoL-1) .
14/09/82 0630 85
(cant.)0730 86 <5 0.7
0830 87
0930 88
1030 89
1130 90 0.9
1230 91 0.9
1330 92 5
1430 93 <5 1.2
1530 94
1630 95 <5 1.2
1730 96
1830 97 <5 1.1
1930 98 <5
2030 99 1.1
2130 100 <5 0.8
2230 101
2330 102 8
15/09/82 0030 103 0.7
0130 104
0230 105 11 1.2
0330 106
0430 107 0.5
0530 108
0630 109 6 0.5
0730 110
0830 III 12 0.9
0930 112 <5
1030 113 <0.5
1130 114
1230 115 <5 <0.5
~Fish placed in cages.
Not analysed.
-134 -
APPENDIX 9.Comparison of suspended sediment and turbidity values
for triplicate water samples taken from within or outside of a Highet
Creek cage during the August and September 1982 in-situ fish survival
tests.
Date Sample Nonfiltrable Total Turbidity
no.residue residue (FTU)
(mgoL-l)(mgoL-l)
06/08/82 EX 28 a b 424 482 700
28-2 364 436 580
28-3b 340 456 600
06/08/82 EX 30 a 164 270 170
30-2b 424 519 300
30-3b 354 455 280
07/08/82 EX 46 a b 84 173 45
46-2 147 316 45
46-3b 147 254 70
07/08/82 EX 55 a b 88 176 35
55-2 98 187 42
55-3b 58 158 39
08/08/82 EX 69 a 34 122 36
69-2b 244 272 50
69-3b 216 375 70
11/09/82 EX 22 a 108 340 245
22-2b 264 380 250
22-3b 314 438 225
13/09/82 EX 79 a b 304 1160 1550
79-2 586 1280 1550
79-3b 514 1160 1550
abSample collected by Isco automatic pump sampler from within cage.
Sample collected manually just outside of the cage,at the time that
sample "a"was taken.
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