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Hatchery Fish Eating Wild Fish

Salmonids Environment Breeding & genetics +2 more

US - Research at Humboldt State University in California has looked into how many young wild fish are eaten by the relatively large, voracious steelhead released from Trinity River Hatchery each year in Trinity River.

And according to a report in The Times Standard it has prompted many involved with the restoration of the Trinity River and its fishery to question how the hatchery is operated.

The report sasy that the Trinity River Restoration Programme sets goals to get 40,000 naturally spawned steelhead to return to the river, and 10,000 hatchery fish to return to the hatchery.

Since 2002, the numbers of both wild and hatchery fish have been rising, but the hatchery fish have outpaced wild fish in terms of production. For example, in 2006, about 8,000 wild fish returned to the river, while about 32,000 hatchery fish returned. In 2007, about 47,000 hatchery fish returned compared to 7,000 wild fish. the Times Standard says.

The hatchery was built to make up for the loss of 109 miles of prime spawning habitat above Trinity Dam.

HSU fisheries graduate Seth Naman found in his short-term study that tens of thousands of fry produced by fish spawning in the river are eaten by hatchery steelhead released by the hundreds of thousands just below the dam in March, as eggs are hatching in the river.