Prior to 1979, insufficient date existed on muskellunge populations and angler use to guide Wisconsin’s muskellunge management plan. Consequently, a study was conducted from 1979 to o1983 to determine population characteristics and angler use of eight northern Wisconsin muskellunge lakes. Each lake was sampled with fyke nets for two consecutive springs and a randon, stratified roving creel census was conducted along with voluntary registration of angler-caught muskellunge for one open water angling season.
Mean length-at-age of male muskellunge was shorter than for females. Males generally reached sexual maturity one or two years earlier than females and were shorter lived. Because of the slower growth and higher mortality few males reached trophy size and nearly all muskellunge larger than 40 inches were females. Growth of both sexes was related to the density of catostomids. Growth of males was inversely related to muskellunge density. Density of legal-sized (> 30 inches) averaged 0.11 fish/acre and ranged from 0.09 to 0.61 fish/acre; highest densities were found in dark, turbid waters.
Total angling pressure averaged 42.8 hours/acre. In five of the eight lakes muskellunge were the most sought after species. Overall, 42.2% of all angler trips were specifically for muskellunge. Muskellunge anglers fished an average of 16.8 hours/acre; exploitation rates averaged 27.5% and ranged from 13.8% to 42.0%. Quality of size structure of legal-sized populations was inversely related to angler exploitation rates. The 30 inch size limit regulation during t his study failed to protect female muskellunge until their first spawning. In some lakes, high exploitation rates appeared to be limiting trophy muskellunge angling potential.