Length‐Based Assessment of an Artisanal Albulid Fishery in the South Pacific: a Data‐Limited Approach for Management and Conservation

Abstract

Data‐limited fisheries assessment methods have great potential to help inform small island communities on the status of their fisheries resources. In this paper, we provide a length‐based assessment of an artisanal fishery that primarily targets spawning aggregations of Shortjaw Bonefish Albula glossodonta at Anaa Atoll in the Tuamotu Archipelago of French Polynesia. We assessed the length‐frequency distribution of the spawning stock across a 3‐year period (2016–2018). During this time, male and female Shortjaw Bonefish were fully recruited to the fishery at age 4 and age 5, respectively. Fishing mortality was over two times the range of natural mortality for this species (i.e., 0.21–0.32), and based on these estimates of natural mortality, the annual spawning potential ratio of the population was between 7% and 20% across the sampling years. The majority of the catch was sexually mature, with 78, 95, and 95% of the annual female catch in 2016, 2017, and 2018, respectively, being equal to or greater than the length of first maturity (i.e., 48 cm FL). However, every fisheries indicator and biological reference point suggested that the fishery was overexploited and in need of management intervention. To this aim, the community of Anaa (1) established an Educational Managed Marine Area, which overlaps with the Shortjaw Bonefish migratory corridor adjacent to Tukuhora village and (2) instated a temporal rahui (a traditional conservation method) inside the Educational Managed Marine Area during the peak months of the spawning season.

The life history of longnose emperors (Lethrinus olivaceus) and a data‐limited assessment of their stock to support fisheries management at Rangiroa Atoll, French Polynesia

“…The fact that immature fish are not targeted by this fishery and that it continues to provide such a large yield is positive. Nonetheless, the yields of spawning aggregation fisheries are known to be hyper stable and often mask the declines in the stock's health (Erisman et al ., 2011; Filous et al ., 2019b; Mullon et al ., 2005; Sadovy de Mitcheson & Erisman, 2012). The results of this length‐based stock assessment indicate that when using the mean estimate of natural mortality, the SPR of this stock was at 23% across the years of this study, and that the fishery is fully exploited.…”

“…To this end, an important starting point in the process of empowering communities to manage their fisheries is providing an assessment of their fisheries and an evaluation of management actions that could be implemented to improve their status (Crosman et al, 2020;Johnson et al, 2020a). Length-based stock assessments have proven effective in informing communities on the status of their resources, promoting management and measuring the biologic response of fish populations to management interventions (Filous et al, 2019b(Filous et al, , 2021Prince et al, 2015). These methods are costeffective and easy to implement, but require a basic understanding of the life-history parameters of targeted species and an adequate representation of the size distribution of the fish harvested in a given fishery (Hordyk et al, 2015a(Hordyk et al, , 2016.…”

ESTIMASI PARAMETER POPULASI DAN RASIO POTENSI PEMIJAHAN TONGKOL KOMO (Euthynnus affinis, Cantor 1849) DI PERAIRAN SELATAN LOMBOK

“…Banyaknya indukan yang tertangkap dan didukung pula oleh hasil VPA, justru bertentangan dengan "prinsip kelestarian Froese" yang ketiga. Pada perikanan yang terkelola dengan baik, target laju penangkapan pada indukan adalah 0% (Filous et al, 2019). Lebih lanjut, ketersediaan indukan 30-40% dalam stok akan menjamin kelangsungan perikanan, sedangkan kurang dari 20% menandakan terjadinya eksploitasi berlebih (Froese, 2004).…”