Hatchery-spawned salmon from Alaska and Japan may someday dominate wild salmon in the North Pacific, interbreeding with them and degrading their ability to adapt to changing conditions, says a U.S.-Canada research team in a just-published article reported by Canada's Globe and Mail. The researchers found a record-high population of pink, chum and sockeye salmon in the North Pacific -- double 1950s estimates -- but worry that too many of the adults returning to spawn are from hatcheries.
From The Globe:
Adult hatchery salmon now account for at least 20 per cent of the total adult salmon production and continue to rise. For some salmon, the percentage is significantly higher. In Asia, 76 per cent of all adult chum salmon from 1990 to 2005 came from salmon hatcheries.
Unless international agreements are developed to manage production levels, hatchery fish may dominate the ocean, [research team member Randall] Peterman said.
Even though the salmon population appears huge, there are still mysteriously low salmon runs in western North America rivers where they previously were robust.