Survival Estimates for Juvenile Fish Subjected to a Laboratory-Generated Shear Environment
Juvenile rainbow trout and steelhead Oncorhynchus mykiss, spring and fall chinook salmon O. tshawytscha, and American shad Alosa sapidissima were exposed to shear environments in the laboratory to determine the rate of strain that would kill or injure them. Fish were exposed to a submerged jet of water with exit velocities adjustable from 0 to 21.3 m/sec. The exposure strain rates for our tests ranged from 0 to about 1100 sec-1. The greatest strain rate tested is beyond rates expected in most natural fish habitat or during passage through the turbine intake of a hydroelectric dam. The rate of strain experienced by test fish varied based on a change in distance or scale of 1.8 cm, the approximate width of the fish tested. Turbulence intensity in the area of the jet where fish were subjected to the shear environment was +3 to 6% of the estimated exposure strain rate. Injuries and mortalities increased with increasing strain rates. There were no significant injuries to any fish subjected to rates of strain !U500 sec-1. American shad were the most susceptible to injury after being subjected to a shear environment while steelhead and rainbow trout were the most resistant. Fish exposed head first to the jet had higher injury/mortality rates than fish introduced tail first. Our studies reinforce past conclusions that a one-time exposure to shear environments exceeding a change in velocity of 15 m/sec over 1.8 cm is harmful to juvenile fish. The associated exposure strain rate for these velocities is ~850 sec-1 at a measurement scale of Dy = 1.8 cm.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 15007430
- Report Number(s):
- PNNL-SA-35935; 820101000
- Journal Information:
- Transactions of the American Fisheries Society, 133:447-454, Journal Name: Transactions of the American Fisheries Society, 133:447-454
- Country of Publication:
- United States
- Language:
- English
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