Development of a Natural Rearing System to Improve Supplemental Fish Quality, 1996-1998 Progress Report [electronic resource].
- Portland, Ore : United States. Bonneville Power Administration, 2001.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy.
- Physical Description:
- 174 pages : digital, PDF file
- Additional Creators:
- United States. National Oceanic and Atmospheric Administration
United States. Bonneville Power Administration
United States. Department of Energy. Office of Scientific and Technical Information
- This report covers the 1996-1998 Natural Rearing Enhancement System (NATURES) research for increasing hatchery salmon postrelease survival and producing fish with more wild-like behavior, physiology, and morphology prior to release. Experiments were conducted evaluating automatic subsurface feeders; natural diets; exercise systems; seminatural raceway habitat enriched with cover, structure, and substrate; and predator avoidance conditioning for hatchery salmonids. Automatic subsurface feed delivery systems did not affect chinook salmon depth distribution or vulnerability to avian predators. Live-food diets only marginally improved the ability of chinook salmon to capture prey in stream enclosures. A prototype exercise system that can be retrofitted to raceways was developed, however, initial testing indicated that severe amounts of exercise may increase in culture mortality. Rearing chinook salmon in seminatural raceway habitat with gravel substrate, woody debris structure, and overhead cover improved coloration and postrelease survival without impacting in-culture health or survival. Steelhead fry reared in enriched environments with structure, cover, and point source feeders dominated and outcompeted conventionally reared fish. Exposing chinook salmon to caged predators increased their postrelease survival. Chinook salmon showed an antipredator response to chemical stimuli from injured conspecifics and exhibited acquired predator recognition following exposure to paired predator-prey stimuli. The report also includes the 1997 Natural Rearing System Workshop proceedings.
- Published through SciTech Connect.
Maynard, Desmond J.
- Type of Report and Period Covered Note:
- Funding Information:
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