A federal judge has left protections in place for wild Central Valley steelhead trout.
The move comes as the government recalculates how their population has been affected by hatchery-raised trout.
The decision also means five Central Valley irrigation districts won´t have to put more water into rivers to aid the fish while the recalculation continues.
The ruling is the latest fallout from a September 2001 court finding that hatchery fish must be considered when wild stocks are proposed for protection under the Endangered Species Act.
Scientists and fishermen have criticized the decision, saying hatchery fish are genetically and behaviorally inferior to naturally born fish in wild conditions.