Economic and Conservation Impacts of Stocking Wild Florida Bass into Large Florida Lakes

摘要

Supplemental stocking of fingerling or advanced fingerling Largemouth Bass Micropterus salmoides is a common management strategy for augmenting natural production in low-recruitment systems. Few studies, however, have evaluated the impact of stocking adult bass taken from donor lakes. Over a period of 6 years, University of Florida researchers stocked Florida Lakes Griffin and Dora with 24,781 wild Florida Bass M. s. floridanus collected by electrofishing from other Florida lakes. During stocking years, stocked fish made up to 10% of the population in Lake Griffin and 27% in Lake Dora from electrofishing samples. However, 1 year after all stocked fish had been released, the proportion of stocked bass had declined to less than 5%, and 3 years after it had declined to less than 1%. We did not detect an increase in recruitment (catch of age-1 bass) following stocking, so any benefit from stocking was likely short-lived. We also could not conclude that stocking was responsible for increasing fishing effort because total fishing effort did not increase after stocking. As a result, no additive economic benefits could be attributed to the stocking program. During randomized electrofishing sampling, we collected 51 wild bass that had been released during the stocking program, and genetic analysis determined that two (3.9%) were hybrids and had alleles from nonnative Largemouth Bass. The extrapolation of these results estimated that almost 1,000 hybrids had been introduced into Lakes Griffin and Dora, which were historically identified to contain pure Florida Bass populations. Future wild bass stocking programs should include an appropriate study design for evaluating changes in fish populations, changes in the fishery, and economic consequences of stocking. Furthermore, a risk-benefit assessment should be completed before any stocking program is initiated, including consideration of any potential impacts on biodiversity.