Aligning fisheries management with life history in two commercially important groupers in Chuuk, Federated States of Micronesia

Abstract

Camouflage grouper, Epinephelus polyphekadion (Bleeker, 1849), and squaretail coralgrouper, Plectropomus areolatus (Rüppell, 1830), are commercially important medium‐bodied groupers that aggregate at specific sites and times to spawn and are highly vulnerable to fishing during these events. Populations of both species are in decline globally, such that management specifically targeting these species is warranted. A 12‐month fish market survey in Chuuk, Federated States of Micronesia, provided an opportunity to examine age‐based reproductive life history of these two groupers and assess whether current management acts to conserve them. Life history characteristics of both E. polyphekadion and P. areolatus include a functionally gonochoristic sexual pattern and rapid growth particularly during early life history. P. areolatus demonstrated early maturity (2.8 years) and a relatively brief lifespan (10 years), while delayed maturity (4.5 years) and higher longevity (25 years) was shown for E. polyphekadion. The spawning seasons for E. polyphekadion and P. areolatus were 2 and 3 months, respectively, which fall entirely within the January–April grouper sales, catch, and export ban period for Chuuk. Marketed catch included 22% E. polyphekadion and 15% P. areolatus juveniles, suggesting that size limits may aid in the conservation of these species. Findings from this and recent grouper life history studies suggest that the current 4‐month ban in Chuuk be applied only to grouper species known to reproduce during these months to minimize economic impacts to fishers and market owners, and prevent shifts in fishing pressure to more vulnerable species, such as those with low population turnover times, slow growth, or late maturity. Size limits for catch, sale and export are also warranted as an additional management option.

Evaluating Age and Growth Relationship to Ciguatoxicity in Five Coral Reef Fish Species from French Polynesia

“…Due to the high heterogeneity observed in the sample size between study sites and the limited number of specimens (10 ≤ n < 20) in at least one of the sites (Table S3), comparisons between species or sites were not possible, emphasizing the need for additional sampling efforts in the future to confirm these results. However, these size, weight, and age data are consistent with those previously observed in the East Asia and Pacific regions for the three parrotfish species [39][40][41], the orangespine unicorn fish [42,43], and the marbled grouper [44,45].…”