Interesting info from an Alabama study...
Black crappie Pomoxis nigromaculatus and white crappie P. annularis often experience dramatic variation in year-class strength, making their management difficult. We sought to identify factors influencing age-0 crappie in an effort to better understand their variable recruitment. Toward this end we quantified adult crappie fecundity, zooplankton abundance, growth and survival of larval and postlarval crappie, and weather and hydrologic factors within three lakes of varying trophic state hypereutrophic Lake Weiss, eutrophic Jones Bluff Lake, and mesotrophic Lake Martin. Reproductive crappie in Martin were older, but had lower relative weight (Wr), and lower mean gonadosomatic index (GSI) values than in the other lakes. In Weiss, crappie were youngest and shortest, but had the highest GSI and Wr values. Jones Bluff crappie were longest, but lowest in Wr and intermediate in age and GSI. While both GSI and fecundity were positively correlated with lake productivity, larval crappie density was either unrelated to or inversely related to GSI. Although collected larvae were of similar age and size, larval growth and survival both appeared to be positively correlated with lake productivity. Juvenile crappie in Jones Bluff grew fastest. These results suggest that recruitment may not be limited by adult spawning potential and there may exist a bottleneck during crappie early life stages in less productive lakes. Gear comparisons indicated that bottom trawling and electrofishing were not viable methods for sampling YOY crappie in our lakes, and a neuston net, although effective for capturing age-0 individuals of several species, was only useful for collecting crappie in shallow areas. Trap nets remained the most effective gear for estimating age-0 crappie abundances in the fall, and an experimental small mesh trap net proved effective in capturing smaller fish including age-0 crappie.
