The Bahamas’ Nassau grouper ( Epinephelus striatus) fishery – two assessment methods applied to a data – deficient coastal population

Abstract

The Nassau grouper is an important fish species in the reef ecosystem of the Bahamas. It is subjected to intense exploitation by small-scale fisheries and is harvested with different fishing gears, primarily during the winter spawning season. The piecemeal nature of the fishing operations precludes an economically feasible way to compile data to assess the status of exploitation of the resource. There is public and governmental concern regarding over-exploitation of the Nassau grouper due to the numerous extinctions of spawning aggregations in the greater Caribbean. Due to the large size of the Bahamas archipelago, where many Nassau grouper spawning aggregations still occur, the collection of appropriate data for stock assessments is very difficult. In addition, stock assessment algorithms that are applicable to tropical, seasonally aggregating species are noticeably lacking. In this paper we present applications of analytical and hydroacoustic assessment algorithms to the Nassau grouper fishery in the Bahamas that could be implemented under data-limited conditions. The results of the analyses indicate that the methods generate consistent abundance and mortality rate estimates that are commensurable with a stock subjected to full exploitation.