The already productive coho salmon fishery on Lake Oroville got another shot in the arm recently, as nearly 230,000 juvenile coho salmon were planted as part of a co-operative project by the Department of Water Resources and Department of Fish and Game. The little cohos averaged 6 to 8 inches long, according to the DWR's biologist Julie Brown. Previous studies have shown that the cohos grow about an inch per month in the lake, and on average live for two years.

The cohos were raised at the Feather River Hatchery, from 320,000 eggs purchased from the Aquaseed facility in Washington State. All of the fish have a coded wire tag implanted in their nose. About 17,000 of the planted fish are experimental "triploids", which are neither male nor female. Triploids cannot reproduce, and often grow faster and to a greater maximum size than other fish.

Brown also advised that the DWR is exploring the possibility of planting some 5,000 juvenile steelhead into the Thermalito Afterbay. If it happens, the steelhead planting would resume the formerly very popular program that had not seen any new fish planted during the previous two years. The yearling steelhead would be planted in January 2012, if the DWR and DFG determine that enough surplus steelhead eggs exist for the current needs of the Feather River.

Anglers on the lake are already feeling the small coho's presence, reported Fil Torres at Oroville Outdoors. "They are like little piranhas all over the place", observed Torres. "In particular the bass anglers are running into the cohos near the mouth of the North Fork, and even down into Potter's. Let them go so they can grow up."