Life in the Slow Lane: Ecology and Conservation of Long-Lived Marine Animals

Groupers (Serranidae, Epinephelinae): Endangered Apex Predators of Reef Communities

Gene R. Huntsman, Jennifer Potts, Roger W. Mays, and Douglas Vaughan

doi: https://doi.org/10.47886/9781888569155.ch17

Abstract. —Distributed worldwide in warm water reef systems, groupers display ecological and biological characteristics that engender overharvest and, in extreme cases, endangerment to particular species. Most of the larger groupers have low natural mortality rates, reach maturity and maximum size slowly, are inherently rare, move little as adults, often aggregate to spawn at locations known to fishers, and are protogynous. The larger groupers of the Atlantic coast of the southeastern United States illustrate the vulnerability of groupers in general and offer reasonable proxies for the condition of many grouper populations throughout the world. The interaction of fishing mortality and protogyny has reduced the frequency of male gag Mycteroperca microlepis to 6% from more than 20% in 1973 and the spawning potential ratio (SPR) based on male biomass to 0.03 (from 1.0 in the unfished population). Reproduction in the protogynous red porgy Pagrus pagrus failed when the male SPR fell below 0.10. For the speckled hind Epinephelus drummondhayi in 1990 the numerical population was 10%, the population biomass was 5%, and the biomass of mature fish was 2% of that existing in 1973. The warsaw grouper E. nigritus is now so rare that too few individuals are measured to assess the population status. Jewfish E. itajara and Nassau grouper E. striatus are so rare as to be totally protected from harvest. The marbled grouper E . (Dermatolepis ) inermis may not be overfished but is so inherently rare that its population status is a mystery. Of the several potential management schemes for groupers only the implementation of a system of marine reserves solves all the complex problems of managing these valuable fishes.