The Idaho Department of Fish and Game plans to form a working group to understand why only 27 of 660,000 juvenile fish raised in the hatchery and released in central Idaho in 2018 survived the two-year, 1,800-mile roundtrip to the ocean and back to return as adults. Fisheries managers expected about 800.

The working group will “look at possible mechanisms that could have contributed to the poor survival,” said John Powell of Fish and Game. The working group is expected to be formed in November.