Effects of Length and Bag Limits on Population Structure and Harvest of White Crappies in Three Texas Reservoirs

In 1985 harvest regulations on crappies Pomoxis spp. were changed from no limits to a 254-mm minimum-length and a 25-fish daily bag limit at three Texas reservoirs. The objective was to increase the proportion and relative abundance of large crappies and thereby increase harvest rate, yield, and mean weight of harvested fish. Changes in the stock structure and harvest of white crappies P. annularis were monitored after the limits were imposed. The proportion of stock-size (≥127 mm) white crappies that were of preferred size (≥254 mm) (RSD-P) increased significantly at Lake Palestine and Lake Meredith (where growth overfishing had occurred), and remained at acceptable levels at Lake Whitney (where growth overfishing did not occur). Mean weight of harvested white crappies increased at one of the two sites where RSD-P increased. Total yield (kg/ hectare) increased at all three reservoirs. Few anglers harvested 25 white crappies/d either before or after the limits were imposed. Results indicate minimum-length limits can alleviate growth overfishing. Where growth overfishing is not occurring, length limits can maintain yield in spite of increased pressure. In addition, a minimum-length limit may moderate or eliminate the variability or cyclicity inherent in crappie fisheries. By preventing harvest of small crappies, which are attractive to anglers only when abundance of larger fish is low, minimum-length limits may help maintain a more stable supply of preferred-size crappies.