A Long-Term Comparison of Yellowstone Cutthroat Trout Abundance and Size Structure in Their Historical Range in Idaho

Autor:	Daniel J. Schill, F. Steven Elle, Kevin A. Meyer, William C. Schrader
Rok vydání:	2003
Předmět:	Ecology biology Range (biology) Management Monitoring Policy and Law Aquatic Science biology.organism_classification Population abundance Fishery Trout Electrofishing Hydro energy Abundance (ecology) Oncorhynchus Environmental science Fish Ecology Evolution Behavior and Systematics
Zdroj:	North American Journal of Fisheries Management. 23:149-162
ISSN:	1548-8675 0275-5947
Popis:	We compared estimates of population abundance and size structure for Yellowstone cutthroat trout Oncorhynchus clarki bouvieri obtained by electrofishing 77 stream segments across southeastern Idaho in the 1980s and again in 1999–2000 to test whether populations of Yellowstone cutthroat trout had changed. Sites sampled in the 1980s were relocated in 1999–2000 by using maps and photographs or by finding original site-boundary stakes, so that the same reach of stream was sampled during both periods. Abundance of Yellowstone cutthroat trout longer than 10 cm did not change, averaging 41 fish/100 m of stream during both the 1980s and 1999–2000. The proportion of the total catch of trout composed of Yellowstone cutthroat trout also did not change, averaging 82% in the 1980s and 78% in 1999–2000. At the 48 sites where size structure could be estimated for both periods, the proportion of Yellowstone cutthroat trout that were 10–20 cm long declined slightly (74% versus 66%), but the change was due entirel...
Databáze:	OpenAIRE
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