Changes In Yellow Perch Demography After A Commercial Fishing Closure In The Indiana Waters Of Lake Michigan
Paul J Allen, Ball State University, Aquatic Biology and Fisheries Center, Muncie, IN 47306; (765) 285-8804; FAX (765) 285-8803; pallen@bsu.edu
Thomas E. Lauer, Ball State University, Aquatic Biology and Fisheries Center, Muncie, IN 47306
The yellow perch has historically been an important commercial and sport species in southern Lake Michigan. An increase in yellow perch abundance during early 1980s allowed for the establishment of a significant commercial fishery from 1983 to 1994 in Indiana waters of Lake Michigan. As perch abundance increased during the 1980s, harvesting of yellow perch by commercial fishers rose by an order of magnitude. By the mid 1990s yellow perch abundance had precipitously declined as a result of successive year class failures. Concerns about excessive harvest, salmonine bycatch, and the impact on yellow perch stock structure resulted in changes to regulation and eventual closure of commercial fishery in 1997. We analyzed our annual sampling data from 1975 to 2003 in an attempt to understand the impact commercial fishing had on yellow perch population dynamics. During years the commercial fishery was in place, gear selectivity resulted in truncated length frequency and age distributions. In addition, sex ratios were skewed towards smaller slower growing males as the faster growing females were being targeted by the commercial gear. Following the closure of the commercial fishery larger more robust fish have been observed, while sex ratios have shifted towards female dominance. Understanding the mechanisms that impact the yellow perch population in Indiana waters of Lake Michigan will be necessary prior to implementing management strategies that may again allow commercial harvest of yellow perch.