Effects of White Sucker Removal and Stocking on Growth of Fishes in Northern Lakes

Abstract Continued management interest in using White Sucker Catostomus commersonii population manipulations to improve the growth of Northern Pike Esox lucius and potentially competing panfish species provided an opportunity to evaluate White Sucker removal and supplementation in Michigan lakes. Overabundant White Suckers from one lake were transferred into two lakes where higher populations were desired, with fish growth responses being evaluated in each lake and in a control lake pretransfer and at 5 years posttransfer. Criteria for project success were (1) continued low abundance of White Suckers in the removal lake and increased abundance in the recipient lakes; (2) positive growth response of panfish species to White Sucker removals; and (3) positive growth response of Northern Pike to White Sucker additions. After 5 years, White Sucker population abundance and recruitment patterns showed continued survival of stocked adults but little recruitment in stocked lakes and the fish species examined showed no clear positive growth responses to White Sucker manipulations. Fishery managers should carefully consider the costs and benefits of using White Sucker manipulations as a management tool.