Recommended Enhancements to the Gulf Sturgeon Recovery and Management Plan Based on Pearl River Studies

Abstract

The Gulf Sturgeon Recovery/Management Plan defines a strategy for removing the threatened Gulf sturgeon Acipenser oxyrinchus desotoi (subspecies of the Atlantic sturgeon) from federal listing and invites revisions based on new information. The plan's objectives are reasonable and well-stated, but the criteria incorporated within the objectives may be unsuitable for monitoring some Gulf sturgeon populations. We propose the following revisions based on a 5-year study of Gulf sturgeon in the Pearl River system of Mississippi and Louisiana: (1) set specific statistical criteria for detecting population changes with emphasis on defining sufficient sampling effort to minimize type II errors; (2) use simple population models incorporating estimates of population size, mortality, and recruitment to ascertain population trends and define recovery; and (3) define a minimum number of adults within a self-sustaining population (in this case 100). These revisions, while perhaps not universally applicable, are probably appropriate in systems with many outlets, such as the Pearl River, where Gulf sturgeon are most easily sampled in summertime habitats.