Michigan Department of Natural Resources
Fisheries Research Report No.1896, 1981
The Exploitation, Harvest, and Abundance of Largemouth Bass Populations in Three Southeastern Michigan Lakes
Greg W. Goudy
Abstract.-Fishing pressure, exploitation, growth, mortality, harvest, population size-age structure, and abundance of largemouth bass (Micropterus salmoides) were measured in Pontiac, Whitmore, and Kent lakes in southeastern Michigan. The effects of a change in the minimum size limit from 254 mm to 304 mm in 1976, and a 200% increase in bass fishing pressure from the levels of 30 years ago, on bass populations were evaluated. Despite annual fishing pressure as high as 472 hours per hectare, producing exploitation rates ranging from 18% to 48% and total mortality rates from 31% to 53%, one bass population contained 22% more bass 254 mm and larger (20.2 bass per hectare) now than 30 years ago. There was a significant catch-and-release fishery of sublegal bass with from 200% to 600% more bass being caught and released than harvested. Though there was a greater percentage of large bass harvested than in the past, the number of bass harvested by anglers has fallen 25% and catch rates for harvested bass have dropped considerably to an average of 0.06 bass per hour .
Creel census clerks used a questionnaire to obtain angler opinions on bass fishing in Michigan. Seventy-seven percent of 1,113 fishermen interviewed responded that they fish for bass in Michigan at least once a year. Of the 862 bass anglers questioned, 27% reported that they usually release their catch. If there was catch-and-release fishing prior to the season opening, 58% of the bass anglers would approve delaying the opening of the bass season from late May until July 1 in order to increase the size of bass available for harvest. Fifty-two percent of the bass anglers would rather catch one large bass than four small (but legal size) bass.
Fishermen reported catching more bass but keeping fewer as a result of the size limit change. However, most anglers were happy with the new regulation citing that though they were keeping fewer bass, they were catching more large bass than before.