By T.G. Northcote, T.G. Halsey and S.J. MacDonald
British Columbia Fish and Wildlife Branch Department of Recreation and Conservation
From the Introduction:
"The objective of this study, "Task 115 - Fish Population and Analysis", under the Limnology Task Force of the Canada-British Columbia Basin Agreement, were to (1) use fish to assess the present status of eutrophication and pollution in the major Okanagan basin lakes; (2) estimate present abundance of kokanee spawning stocks; and (3) check selected species of fish for chlorinated hydrocarbons, heavy metals and other possible contaminants...
Because of the considerable public concern over pesticided and heavy metals, particularly mercury, in sport fished of the Okanagan basin - a partial ban on eating large trout already had been placed on Okanagan Lake - it seemed logical to broaden the information available in this area."
See the Study [PDF]. Note: scanned copy of original document.