With the arrival of spring, fisheries crews will again be conducting surveys of rainbow trout spawning on the South Fork Madison River and Duck Creek near West Yellowstone.
Fish traps to capture adult rainbow trout will be set up on tributaries to Hebgen Lake, one on the South Fork Madison and one on Duck Creek, to evaluate the spawning population. Screw traps will also be set up on the South Fork Madison and Duck Creek to sample for young-of-the-year and yearling rainbow trout emigrating from these tributaries to Hebgen Lake.
“Based upon spawning surveys conducted since 2001, these two tributaries comprise approximately 70% of the wild rainbow trout production (excluding the main stem Madison) in the Hebgen Basin,” said FWP Fisheries Biologist Pat Clancey.
“The purpose of the trapping is to determine the strength and age structure of the rainbow trout population and determine annual contributions of young fish to the population,” said Clancey.
Downstream migrating juvenile fish previously captured in screw traps and tagged with a coded-wire tag in the snout are now returning adults which will be scanned electronically to determine the proportion that have a coded-wire tag. This provides information about the life histories of the fish from each stream.
“Once the traps are set up, we always get some calls from people wondering what they are,” said Clancey. “The adult traps look like a fence across the stream and the juvenile screw traps look like a rotating aluminum drum set on pontoons and they definitely catch people’s attention.”
Fishermen, recreationists, and others along the two streams should stay clear of the traps for safety reasons.
All of the adult rainbow trout captured in the survey will be fitted with a uniquely numbered and colored tag. Anglers who catch tagged fish are asked to contact the FWP fisheries field office in Ennis at 406-682-7807 and provide the date and location of catch, length and weight of the fish, and the tag color and number.
“The help we get from anglers reporting tagged fish is invaluable to our survey work,” said Clancey. “The angler reports provide information on where the fish are and when they are there, at times of the year when the traps aren’t out.”