Goliath grouper Epinephelus itajara (Teleostei: Serranidae) in the Mexican Caribbean: local ecological knowledge and habitat use

Rare species necessitate alternative survey techniques and, in the case of exploited resources, any attempt to monitor their abundance with a meaningful benchmark should also include local ecological knowledge (LEK) of local users. This study evaluates the status of Goliath grouper (Epinephelus itajara) in the Mexican Caribbean via LEK and also direct acquisition of data on habitat use of the species in Chetumal Bay, taking into account distribution by body size, site, and habitat. We interviewed 124 fishers about their knowledge and experience with Goliath grouper, comparing northern to southern Mexican Caribbean, as well as older vs. younger fishers. The species is a well-identified resource; fishers are able to describe many behavioral and habitat-use traits, but they find it difficult to discern males from females and juveniles from adults. The fishery is opportunistic and the capture is commercialized and consumed only locally. The species has declined over the last decades, the probable cause being the increase in the number of fishers and boats, as well as the use of harpoon by divers. In addition to the interviews, 54 specimens were recorded in Chetumal Bay, standard length 517-1613 mm. Goliath grouper preferred submerged sinkholes and caves, locally called pozas, with water temperature of 23-31 degrees C and salinity of 4.5-30.0 psu, 1.5-40.0 m deep. Although access to pozas can be dangerous-a fact that could favor viability of Goliath grouper-even in these sites, the fishery extracts young and subadult animals, probably affecting population dynamics.

Automated summary

This study evaluates the status of Goliath grouper in the Mexican Caribbean using both local ecological knowledge and direct observations of the species' habitat use. The Goliath grouper is well-identified by local fishers, but they have difficulty distinguishing males from females and juveniles from adults. The species has declined, which is likely due to an increase in fishing activity and the use of harpoon by divers. The Goliath grouper prefers submerged sinkholes and caves with specific water temperature and salinity levels.