Fish-Population and Catch Data from Minnesota Lakes

Abstract

From seining it is concluded that the average game-fish lake of southern Minnesota has a fish population of about 110 pounds per acre of which about one-sixth is made up of large predaceous species. Pike (Esox lucius) is the most widespread and, from the viewpoint of fishery management, the most valuable predatory fish in Minnesota waters. Pike is nearly always a co-dominant with largemouth black bass (Micropterus salmoides) in “bass-panfish” lakes and with yellow pikeperch (Stizostedion v. vitreum) in “walleye” lakes. As a check on populations of yellow perch (Perca flavescens) and small centrarchids, pike are probably more effective than either bass or pikeperch. A comparison of the poundage composition of the anglersˈ take with the poundage composition of the fish population found by seining shows that fishing pressure in Minnesota is much heavier for the large predaceous species than for the panfishes. Pikeperch are subjected to heaviest fishing pressure, with pike second. Rough-fish lakes in southern Minnesota were found by test seining to have an average of about 375 pounds of fish per acre, of which 280 pounds were rough fish, largely carp (Cyprinus carpio). An average removal of 97 pounds per acre per season over 25 years has had no permanent effect in reducing the size of carp and buffalo populations in 14 such waters. In general, rough fish appear to have little effect on the total poundage of game fish in southern Minnesota lakes. Rough fish are, however, usually associated with large populations of crappies (Pomoxis spp.) and somewhat reduced perch and pike populations. Gill-net and hoop-net catches and indices are considered. Fishing selectivity of gill nets and the use of poundage data from gill-net catches in judging the relationship between perch and predatory fish are discussed.