Fisheries for amphidromous postlarvae, most notably freshwater goby species, occur worldwide where returning migrations of postlarvae to rivers are often predictable due to strong synchrony with the lunar cycle. Although these unique fisheries can have high cultural and economic value, they have received little research attention and are commonly managed with few or no regulations. Therefore, a greater understanding of the fishery and harvest dynamics is necessary to ensure conservation and sustainability of this unique aquatic resource. Postlarval Sirajo Goby (Sicydium spp.) are locally referred to as cetí in Puerto Rico and are harvested in low-participation and low-technology, artisanal fisheries. Fishing for cetí occurs monthly at river mouths throughout the western and northern coasts of Puerto Rico from June to January. Our objective was to characterize the postlarval Sirajo Goby fishery and evaluate factors influencing harvest at the mouth of the Río Grande de Arecibo, Puerto Rico, where a popular cetí fishery occurs. We surveyed fishers and weighed their catch in July 2014 and 2015 to characterize the participation and harvest of this cetí fishery. We estimated Sirajo Goby harvest (total weight and individuals) and evaluated relationships of Sirajo Goby catch with effort, timing, and tide height using linear regression.
Results/Conclusions
Overall, the results of our survey provide the first estimates of cetí harvested during two postlarval migration events in Puerto Rico and will be essential to guiding future conservation and management efforts. The fishery for post-larval Sirajo Goby was of short duration (2-3 days) in both years and strongly skewed toward low light periods before sunrise. In 2014, estimated total harvest was 89.9 kg, comprised of approximately 1.1 million individuals. Harvest in 2015 was 64.7 kg representing an estimated 511,866 individuals. Total effort (group-hours) was the strongest predictor of post-larval catch in both years, but greater variability was observed in 2015 and may have resulted from variation in location of effort and harvest among groups. Future efforts to estimate cetí harvest across broader spatial scales should consider the unique temporal patterns associated with these short-term, periodic fisheries and may be improved by accounting for variation from several potential sources, such as experience of fishery participants, fine-scale location of harvest, and the variability among fishing gears used to harvest cetí. Our study provides a framework to characterize artisanal post-larval Sirajo Goby fisheries and estimate harvest in Caribbean rivers, which is critical to future management of cetí fisheries in Puerto Rico.