Prolonged Swimming Performance of Northern Squawfish
作者:
MatthewG. Mesa,
ToddM. Olson,
期刊:
Transactions of the American Fisheries Society
(Taylor Available online 1993)
卷期:
Volume 122,
issue 6
页码: 1104-1110
ISSN:0002-8487
年代: 1993
DOI:10.1577/1548-8659(0)122<1104:PSPONS>2.3.CO;2
出版商: Taylor & Francis Group
数据来源: Taylor
摘要:
We determined the prolonged swimming performance of two size-classes of northern squawfishPtychocheilus oregonensisat 12 and 18°C. The percentage of fish fatigued was positively related to water velocity and best described by an exponential model. At 12°C, the velocity at which 50% of the fish fatigued (FV50) was estimated to be 2.91 fork lengths per second (FL/s; 100 cm/s) for medium-sized fish (30–39 cm) and 2.45 FL/s (104 cm/s) for large fish (40–49 cm). At 18°C, estimated FV50 was 3.12 FL/s (107 cm/s) for medium fish and 2.65 FL/s (112 cm/s) for large fish. Rate of change in percent fatigue was affected by fish size and water temperature. Large fish fatigued at a higher rate than medium-sized fish; all fish fatigued faster at 12 than at 18°C. The mean times to fatigue at velocities of 102–115 cm/s ranged from 14 to 28 min and were not affected by fish size or water temperature. Our results indicate that water velocities from 100 to 130 cm/s may exclude or reduce predation by northern squawfish around juvenile salmonid bypass outfalls at Columbia River dams, at least during certain times of the year. We recommend that construction or modification of juvenile salmonid bypass facilities place the outfall in an area of high water velocity and distant from eddies, submerged cover, and littoral areas.
点击下载:
PDF (536KB)
返 回