Rg. Lake et Sg. Hinch, Acute effects of suspended sediment angularity on juvenile coho salmon (Oncorhynchus kisutch), CAN J FISH, 56(5), 1999, pp. 862-867
Citations number
29
Categorie Soggetti
Aquatic Sciences
Journal title
CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES
To determine the roles of suspended sediment angularity and concentration a
s contributors to stress and mortality in salmonids, we exposed juvenile co
ho salmon (Oncorhynchus kisutch) to anthropogenically derived "extremely an
gular" and "round" silicate sediments over a range of concentrations in 96-
h experiments. Stress responses (e.g., decreased leukocrit) were elicited b
y exposure to both sediment shapes when concentrations were >40 g.L-1, corr
esponding to the minimum concentration at which physical gill damage was ob
served. Extremely angular sediments also caused stress responses (e.g., ele
vated hematocrit, decreased leukocrit) at concentrations <41 g.L-1. However
, we found no difference between sediment shapes in causing mortality at an
y sediment concentration. Further, mortalities were not observed until conc
entrations were about 100 g.L-1, a value that is about an order of magnitud
e greater than high natural concentrations in salmonid rivers. Natural fluv
ial suspended sediments cause fish stress and mortality at much lower conce
ntrations than we found with our anthropogenically derived suspended sedime
nts.