In experiments at the Bureau's Salmon-Cultural Laboratory, to determine the excretory products of significance in rearing ponds and the possible effect of these products on fingerling chinook salmon (Oncorhynchus tshawytscha), the results demonstrated that ammonia and urea are the principal products. The relative amounts of these products vary with the concentration of fish and with their metabolic activity. Ammonia assumes dominance in an unfavorable environment. Water temperature, pH, and pond type affect the toxicity of ammonia solutions. Continuous exposure to levels of ammonia normally encountered in rearing ponds produced extensive hyperplasia of the gill epithelium in controlled experiments.
Fisheries by United States. Bureau of Sport Fisheries and Wildlife
Author: United States. Bureau of Sport Fisheries and Wildlife
"In the calendar year 1964, the main efforts of the Division of Wildlife Research were directed toward consolidation of recently expanded programs on pesticide-wildlife relations and nuisance-animal control. A modest increase in activities associated with the captive propagation of rare and endangered birds was accommodated, and a great deal of planning laid groundwork for future work with threatened species. There was no change in purpose and function of the Division"--Page 1.
This bibliography on reservoir fishery biology comprises 1,210 references under 14 general subject headings. Within subject categories, citations are arranged alphabetically by authors, without cross-indexing or multiple iisting. The references include many graduate theses and dissertations, mimeographed State fishery agency administrative reports, and Federal Aid job completion reports concerning reservoirs.