The Walleye Population and Fishery in the Red Cedar River, Wisconsin

[摘要] Walleye, Stizostedion vitreum (Mitchill), were taggedand a partial creel survey conducted in a 12.5 ha segmentof the Red Cedar River, Wisconsin, between the impoundmentsof Tainter Lake and Lake Menomin. Tag returns and electrofishingcatches indicated a high concentration of walleye in theriver during April and early May. Walleye migrated downstreaminto Lake Menomin during summer and upstream in fall.Fish was the most important food item and comprised 84 percentof the total food volume of walleye less than 200 mm longand 97 percent of the total for those larger than 200 mm.Total lengths at annulus formation based on the sum of meanannual increments for each year class were 162, 264, 328, 373,419, 452, 474, 490, 514, 537, 562, and 618 mm for ages Ithrough XII, respectively. Total annual mortality rate determinedfrom catch curves and angler recapture of tagged fish wasestimated to be 50 percent for ages II through IX. Exploitationrate, estimated from angler tag returns corrected for nonresponseand tag shedding, was 31 percent for 1973 and 1974.Anglers fished an estimated 273 and 278 hrs/ha, caught 22 and12 walleye/ha (9.1 and 4.7 kg/ha) at rates of 7 and 4 fish/100 hrs in 1973 and 1974. Mean length of walleye creeled was 362 and351 mm in 1973 and 1974, and 82 percent of the catch was made up of ages II through V. Males and females appeared to beequally vulnerable to anglers. Population estimates, calculatedfrom creel survey data, ranged from 7.6 to 9.7walleye/ha and 3.0 to 3.2 kg/ha with a mean of 8.5 walleye/ha(3.1 kg/ha) for walleye 250 mm and longer. Critical size,the size at which a year class reaches its maximum biomass,was estimated to be between 419 and 452 mm total length, weightsof 663 and 845 grams, or ages V and VI. Calculation of equilibriumyield per unit recruitment indicated that weight harvestedcould be increased by 27, 38, and 35 percent with 328, 373,and 419 mm length limits.

[发布机构] University of Wisconsin-Stevens Point