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Marine fish stock enhancement: status, potential and constraints. Open-water stocking. Reservoirs Salmon, trout, whitefish, striped bass Lakes and streams Largemouth bass, channel catfish Coastal seas Ranching anadromous species Marine fish.
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Marine fish stock enhancement: status, potential and constraints
Open-water stocking • Reservoirs • Salmon, trout, whitefish, striped bass • Lakes and streams • Largemouth bass, channel catfish • Coastal seas • Ranching anadromous species • Marine fish
Potential for marine fish stock enhancement in North Carolina Species of primary interest Summer flounder (Paralichthys dentatus) Southern flounder (P. lethostigma) Red drum (Sciaenops ocellatus)
Approaches to restoring a fishery • Restrict harvesting • Recreational and commercial quotas • Restore degraded nurseries • Remove sources of pollution • Enhance stock • Release hatchery-produced fish
What is the status of the flounder and red drum fisheries in NC? • Landings have declined in recent years. • Stocks are far below historical levels. • Management plans are in place for summer flounder and red drum, but not southern flounder.
When does stock enhancement make sense, and would it replace traditional management techniques? • Declining fishery. • Growing demand. • Excess carrying capacity. • Ineffective management strategies. • Built-in environmental safeguards.
What are the concerns about stock enhancement in the marine environment? • Diluting genetic diversity of wild stock. • Exceeding carrying capacity of receiving waters. • Introducing disease. • Undermining management practices. • Behavioral deficits
Are conditions favorable for stocking summer flounder and red drum in NC? • Stocks are depressed. • Demand for flounders strong, but uncertain for red drum. • High inter-annual variation • in recruitment levels. • in distribution of recruits. • Management targets for summer flounder have not been met.
Favorable conditions in NC for stock enhancement • NC’s extensive coastline provides good habitats for young fish. • Fishing industry is important. • Legislators and community are receptive. • Gear available to monitor and document results of stocking effort. • University system with faculty pursuing marine aquaculture and stock enhancement.
Challenges to stock enhancement in NC • NC in on northern edge of ecological range for red drum and southern flounder. • NC’s large systems of sounds and sound-ocean interactions make tracking stocked fish difficult. • Extensive net fishing in sounds threatens stocked fish.
Is there stock enhancement experience elsewhere to build on? • Japan • Japanese flounder • U.S. • Texas and S. Carolina - Red drum • Florida - Snook, Red drum • Hawaii - Grey mullet and Pacific threadfin
Japanese experience:Factors important for successful stocking • Timing of release. • Size of released fish. • Food availability. • Cooperation from fishermen.
Texas experience:Factors contributing to success of red drum stock enhancement • Banned nets in coastal waters. • Enforced stringent harvest regulations. • Rewards to fishermen for reporting tagged fish. • Education programs. • Strengthened habitat protection.
What are the major elements in designing a responsible stock enhancement program? • Strong research component • Multidisciplinary approach. • Program framework • Develop reliable hatchery as a base. • Build public acceptance. • Educational programs.
Program framework • Prioritize species. • Identify genetic and harvest objectives. • Incorporate genetic, disease and health mgt. • Develop reliable hatchery. • Use pilot releases to identify optimum release protocols. • Mark hatchery fish to assess stocking impact. • Consider ecological impacts.
Program framework • Identify economic and policy guidelines. • Use adaptive management to integrate new information. • Make long-term commitment.