There is a nice study by Marc Schmidt on diver-avoidance in reservoir-dwelling Coregonus albula (similar to the north American cisco)
These fish are a lot smaller than the large-bodied salmonids you are dealing with.
Schmidt, M. B. & Gassner, H. (2006). Influence of scuba divers on the avoidance reaction of a dense vendace (Coregonus albula L.) population monitored by hydroacoustics. Fisheries Research 82, 131-139.
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Dr Chris Harrod
Lecturer in Fish and Aquatic Ecology
Queen's University Belfast
School of Biological Sciences
Medical Biology Centre
97 Lisburn Road
Belfast BT9 7BL
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Tel: +44 (0) 28 909 72271
Mob: +44 (0) 79 77419314
Lab: +44 (0) 28 909 72106
Fax: +44 (0) 28 909 75877
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I am working on a project that will replace some anchor cables on the
two floating bridges that cross Lake Washington in Seattle, Washington.
The project will use a pair of divers to replace these cables in water
from 40 to 200 feet deep. Lake Washington is the largest lake in
Western Washington, and supports a number of salmonid species, including
anadromous sockeye. Adult sockeye are known to find thermal refuge at
50 to 90 feet deep during the warmest part of the summer, and this
season the population is expected to be 105,000.
A question has arisen on the potential impact that two divers would have
on these fish, and I am at a loss to find a source of information. Does
anyone know, or can anyone provide best professional judgment, on the
potential impact of a pair of divers moving vertically through the
thermal refuge layers where sockeye would be dispersed?
NW Region Biology Program Manager
Washington State Department of Transportation
Nelson Resources Consulting, Inc.
954 653 8295
561 449 9637
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