Assessment of experimental panfish enhancement regulations on select Pennsylvania impoundments

In 1999, the Pennsylvania Fish and Boat Commission adopted experimental fishing regulations to evaluate the effectiveness of harvest restrictions for improving the size structure of panfish populations.  Harvest restrictions included reducing species-specific creel limits from 50 to 20 fish/day (while maintaining a combined species creel limit of 50 fish/day) and establishing minimum length limits of 229 mm (9 inches) for black and white crappie Pomoxis nigromaculatus and P. annularis and yellow perch Perca flavescens, and 178 mm (7 inches) for sunfish (bluegill Lepomis macrochirus and pumpkinseed L. gibbosus).  Panfish populations were sampled using trap nets in 6 treatment and 5 control lakes (managed under statewide regulations: 50 fish/day; no minimum length limit).  Pre-implementation sampling occurred periodically over a 17-year period while post-implementation sampling occurred over a 7-year period. We analyzed trap net data to evaluate if the catch per unit effort (CPUE) of large panfish (crappie and perch ≥ 229 mm and sunfish ≥ 178 mm) increased as a result of the regulations.  Results indicated a positive response with average CPUE of large sunfish and yellow perch increasing nearly two-fold and large crappie increasing about three-fold in treatment lakes post-regulation.  Panfish CPUE in control lakes remained largely unchanged over time.