Portland, OR -

A judge has ordered federal managers to do more to ensure that hatchery fish don't harm wild fish on the Sandy River this year.

The Oregonian reports federal Judge Ancer Haggerty's ruling could jeopardize the release of hundreds of thousands of juvenile salmon and steelhead from the Sandy Hatchery this spring -- and mean fewer fish to catch in the river by 2015.

Similar lawsuits cover other rivers in Oregon and in California.

In their suit, conservation groups argued too many hatchery fish interbreed with wild fish. Conservation groups argue that hatchery fish lack genetic diversity and are less well adapted to survive in the wild.

The removal of two Sandy River dams near Portland opened spawning areas but eliminated the barrier used to separate wild and hatchery fish.