Population Structure and Growth of Walleye in Gregoire, Ethel and Hilda Lakes, Alberta, 2007


Author(s)

Brendan Ganton

Summary

High angling pressure, coupled with slow-growing and late-maturing fish, have put Alberta's walleye population under stress. By 1990, many walleye populations in Alberta had declined to a small fraction of their former abundance. To forestall extirpation of these populations and collapse of associated recreational fisheries, Alberta Sustainable Resources Development introduced the Alberta Walleye Management and Recovery Plan (WMRP) in 1995. As part of the WMRP, I conducted gill netting surveys at Gregoire, Ethel, and Hilda lakes during the fall of 2007 to obtain information on the abundance and population structure of walleye in these lakes.

Data from Gregoire Lake suggested that in 2007 the walleye population had a broad age-class distribution that was moderately unstable. The average walleye reached 500 mm FL at age-14. Male walleye reached maturity at age-4, whereas female walleye reached maturity at age-6. The catch rate of walleye was 11.8 walleye/100 m2 /24 h.

Data from Ethel Lake suggested that in 2007 the walleye population had a broad ageclass distribution that was moderately unstable. The average walleye reached 500 mm FL at age-13. Male walleye reached maturity at age-4, whereas female walleye reached maturity at age-7. The catch rate of walleye was 14.6 walleye/100 m2 /24 h.

Data from Hilda Lake suggested that in 2007 the walleye population had a narrow and unstable age-class distribution. The average walleye reached 500 mm FL at age-13. Male and female walleye both reached maturity at age-5. The catch rate of walleye was 15.1 walleye/100 m2 /24 h.

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