Efficacy of Rotenone to Collect Bluegill for Stomach Content Analysis

In 1980 and 1981, bluegill, Lepomis macrochirus, were collected concurrently and in adjacent littoral areas of West Point Lake, a 10,480-ha reservoir (Alabama-Georgia), by seining (S) and by poisoning with rotenone (R). A statistical comparison of total stomach content volume and individual food item volume for Sand R fish was conducted to determine if rotenone caused either gorging or regurgitation of food as reported for some piscivorous fishes. Stomach contents of 744 R and 1,121 S fish were examined. Data were paired by date, site, and fish size. Although significant differences in total stomach content volume for Rand S fish were detected in the majority of comparisons, the number of incidences in which a larger food volume occurred was about evenly divided between Rand S fish. Similar results were observed when comparisons were made on the basis of individual food items. There is no evidence to indicate that bluegill collected with rotenone gorged, regurgitated, or selectively fed on moribund food organisms available to them.

ALI-298-305.pdf380.82 KB
Starting page
298
Ending page
305
ID
8888