OLYMPIA – Steelheaders on the Olympic Peninsula's Hoh River can once again distinguish hatchery steelhead from their wild counterparts by the lack of an adipose fin on hatchery fish, the Washington Department of Fish and Wildlife (WDFW) announced today.
Fisheries managers remove the adipose fin – the small, fatty fin on a fish's back near the base of the tail fin – for easy identification of hatchery fish from wild fish. Three years ago a portion of the hatchery steelhead production released into the Hoh River system was not fin-clipped, requiring anglers to use a different, less-precise wild/hatchery identification process.
WDFW fisheries biologist Mike Gross said the hatchery steelhead released in the spring of 1998 with an intact adipose fin have returned over the past two seasons, clearing the way for a resumption of the adipose fin identification method this season. Hatchery steelhead will have a small healed scar in the place where the adipose fin has been clipped.
"There have been reports of anglers measuring dorsal fins and keeping fish with a short dorsal fin but an intact adipose fin," Gross said. "But the vast majority of hatchery fish returning to the Hoh River system this season are properly marked with a clipped adipose fin, so we are returning to this standard method of identifying hatchery and wild steelhead."
More information on identifying an adipose fin-clipped fish, as well as additional steelheading regulation information, is available in the "Fishing in Washington" 2001/2002 sport fishing rules pamphlet.