Monday, December 19, 2011

Hatchery Vs. Wild

This is a summary of some of the issues of hatchery impacts on the productivity of wild salmon and steelhead. It is a interesting read as well as everything found on Bill Bakke's, Home Waters and Wild Fish.

By Bill Bakke

Naturally spawning hatchery fish from long term hatchery cultivation produce 6-11% to the adult stage compared to wild fish. ( Leider et al. 1989, Araki et al 2006)

In the first generation native broodstock hatchery fish (using wild steelhead for hatchery broodstock) the reproductive success of the hatchery fish spawning naturally in streams declines by 14% (males) and 2% (females) compared to wild fish spawning naturally in the river. (ISRP 2011)

In later generations (second and third) the reproductive success of native broodstock hatchery steelhead spawning naturally in streams is 50% (males) lower and 77% (females) lower than naturally spawning wild fish. (ISRP 2011)

There is a genetic change in the hatchery steelhead that carries over to naturally produced progeny of hatchery-origin parents causing reduced reproductive fitness of wild-born descendants in the wild and the population fitness of subsequent generations. (Araki et al. 2009, ISRP 2011)

In just 6 generations native broodstock hatchery steelhead reproductive success is 29% to 54% that of wild steelhead. (Berntson 2011)

In order to maintain cost effective hatchery programs, access to healthy abundant wild steelhead populations is required. (Based on research by Araki et al. 2008)

In order to protect and rebuild wild salmon and steelhead populations harvest targeted on hatchery fish must be regulated to protect wild spawner abundance, spawner abundance goals need to be adopted by species and watershed, hatchery transfers among watershed need to be eliminated, and naturally spawning hatchery fish need to be excluded from wild fish spawning areas. (Conclusions base on best available science)

Impacts of hatchery fish on wild fish must be controlled so that competition for food and space for rearing juveniles in streams and the estuary support wild fish survival, predation and predator attraction by hatchery fish is controlled to protect survival of wild fish, and nutrient enrichment targets from natural spawning wild fish support and expand the productive capacity of the habitat. (Conclusion based on best available science)

Competition between wild and hatchery fish spawning naturally in a common habitat can reduce the production of wild juveniles by 50% (Kostow 2004)

The cost to produce a hatchery steelhead that contributes to the catch is $200 to over $400 per fish harvested. Most hatchery programs funded with tax dollars are not cost effective, making the hatchery program vulnerable to loss of funding as hatcheries compete for funding with other social needs for available dollars. . (Hans Radtke 2011, IEAB 2000)

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