MAR News

Fishing Sampling
Photo: Mar Alliance

by: Ivy E. Baremore, PhD
MarAlliance

The deep waters of the western Caribbean are home to long-lived snappers and groupers, commercially important, yet understudied species. This project provided some of the first information on the reproductive periodicity, life history, connectivity, and distribution of the deepwater snapper/grouper complex in the western Caribbean. Working with ten fishers in Belize and Honduras, MarAlliance deployed 159 vertical longlines (24 in Belize and 75 in Honduras) and 14 deepwater cameras outfitted with hydrophones (three in Belize and 11 in Honduras) to investigate the life history and ecology of 148 of these species. The research was conducted in three protected areas: Southwater Caye and Glover’s Reef Atoll in Belize, and the Bay Islands National Marine Park in Honduras. 

Analysis of age, growth, and reproduction revealed that deepwater snappers and groupers are long-lived, with the longevity of the cardinal snapper (Pristipomoides macrophthalmus) validated to 60+ years using bomb radiocarbon dating (Baremore et al. In review). Other species were found to have similarly long lives, with blackfin snapper (Lutjanus buccanella) aged to 36 years and silk snapper (L. vivanus) to more than 40 years. Additionally, misty (Hyporthodus mystacinus) and yellowedge groupers (H. flavolimbatus) previously collected, also through the support of another MAR Fund grant, were found to be more than 80 years old. Reproductive analysis revealed that most deepwater snapper and grouper species spawned during the fall months (August-December), but no evidence of spawning aggregations was observed. Hydrophones deployed with camera installations did not reveal immediate evidence of spawning, sound file analysis is ongoing.

Preliminary genetic analysis of cardinal and silk snappers found no evidence of barriers to gene flow for silk snappers. However, cardinal snappers at Lighthouse Reef Atoll were found to be genetically removed from those in southern Belize. This suggests that the cardinal snappers at the most remote sites may need separate management strategies. Silk snappers can likely be managed as one stock in the region. 

Project findings were included in a recent publication, which revealed that snappers in Honduras, where the fishery is larger and older, were smaller and less abundant than those in Belize, where the fishery is smaller and younger (Baremore et al., 2023). These data and others have been used to develop an Ecological Risk Assessment for the fishery, which indicated that all of the deepwater grouper and snapper species are highly vulnerable to overfishing (Baremore, 2024). 

Based on the project’s findings, it is recommended that measures such as limited access and closed seasons are needed for deepwater groupers and snappers. Although resources are limited across the MAR region for enforcement of new management plans specifically for deepwater species, managers could take advantage of existing protected areas and legislation by extending ‘no take’ zones to the 500 meter depth contour. Seasonal fishery closures or at existing MPAs should be considered during the fall months (August-October) to allow for reproduction. This is especially true for the long-lived grouper species, which tend to be more spatially restrained and highly vulnerable to extirpation (Sadovy De Mitcheson et al., 2020). 

This project was supported by the Traditional Window of the 14th Request for Proposals of MAR Fund’s Small Grants Program.

Video: MarAlliance