Based on the relative abundance of yellow perch in Fresno Reservoir, Fish, Wildlife & Parks will suspend the stocking program that has boosted the population for the last four years.
Last year’s assessment of the perch population in the reservoir northwest of Havre indicated that adult yellow perch populations are their highest on record in Fresno, reports Bill Wiedenheft, FWP’s regional fisheries manager based in Glasgow. Wiedenheft credits a program that transferred adult yellow perch from northwest Montana’s Lake Mary Ronan with Fresno’s rebounding perch population. Yellow perch are a vital food source for Fresno’s walleye and northern pike and a popular fishery for anglers. Rising water levels that increased perch habitat are a contributing reason for the rebounding perch populations.
“The elevated perch numbers are due to the success of the transfer of pre-spawn adult yellow perch from Lake Mary Ronan from 2001 through 2004,” says Wiedenheft. “The program was initiated following successive years of extremely poor yellow perch production in Fresno. After stocking a total of 170,734 perch, abundance of young-of-the-year perch has dramatically increased” and exceeded the department’s goal to continue the transfer program.
“Upon initiation of this program, FWP fisheries biologists set a catch-rate goal of 3 adult perch per net,” says the fisheries manager. The catch rate is determined from annual fall gill-netting surveys. During these surveys, nets are set at 12 fixed sites throughout the reservoir over a two-day period. In the fall of 2001, those 12 nets collected a total of only 39 young-of-the-year perch, triggering the Lake Mary Ronan transfer effort. In 2003, more than 1,800 young-of-the-year perch were sampled at the same dozen netting sites, and in 2004 the total neared 3,000 fish, or 9.75 perch per net, far greater than the goal of 3 perch per net.”
“Those 2004 catch rates are the highest on record for Fresno Reservoir,” says Havre-area fisheries biologist Laura Leslie, who also credits rising water levels in the springs of 2003 and 2004 that allowed adult perch to take advantage of flooded shoreline spawning habitat.
“Fresno’s young-of-the-year perch populations are higher than they have been since the mid 1990’s and will continue to increase if the water levels are amenable to spawning this spring,” says Leslie. “Planting additional adults in 2005 will not significantly increase the yellow perch population, as plenty of pre-spawn adults are currently present.”
Because the perch transfer effort has been so popular among Fresno’s walleye and pike anglers, Fish, Wildlife & Parks plans to address the suspension of the program at a public meeting next month. The April 5 meeting location has not been finalized.