Dorsal Fin Spines and Rays for Nonlethal Ageing of Goliath Grouper Epinephelus itajara

Atlantic Goliath Grouper, Epinephelus itajara, the largest grouper in western North Atlantic, exhibits life history characteristics (e.g., it is slow-growing, long-lived, and late-maturing) that make particularly susceptible to fishing pressure. Otoliths, structure typically processed for age determination, are usually collected as part of fishery monitoring, but otoliths not available from Grouper due a harvest moratorium enacted 1990 United States waters. Alternative structures—such dorsal fin rays or spines—can be acquired ageing via nonlethal sampling may provide reliable estimates. Since 2006, Florida Fish Wildlife Conservation Commission (FWC) has been collecting incidental samples mortality events including those cold kills red tides. Corresponding otolith, ray spine were compared determine accuracy precision external structures. Marginal increment analyses indicated annulus (translucent zone) deposition occurred primarily March–June on spines April–June rays. While ages determined both exhibited high precision, otolith was low result systematic underageing structures, at oldest classes. A correction factor applied remedied underageing, more successful spines. An analysis section based removal fish (i.e., comparing sections base within body sectioned surface body) can accurately aged when sampled distal structure, cannot. Nonlethal facilitated by public participation could address management goals help offshore population structure. Simultaneously, contribute critical data needed traditional stock assessment, should such path warranted recovery species.