Ecological insights to inform management of shark catches in Muncar, Indonesia

Journal article

Shark populations face global declines, primarilyas a result of overfishing. These declines threaten marineecosystems and require urgent conservation attention.Despite advances in global regulatory frameworks, catchrates of threatened and CITES-listed sharks remain high.Indonesia, as the world’s largest shark-fishing nation, is apriority country where fisheries management is needed tohalt and reverse shark population declines. This studyinvestigates the operational and ecological characteristics ofshark fishing in Muncar, East Java, a major shark fishinghub in Indonesia, to derive sustainability indicators andinform management strategies. We utilized daily landingsdata and spatial analysis to examine the overall state of thefishery, derive simple size-based sustainability indicators,and identify spatial, temporal and operational predictors ofcatches of threatened species as leverage points for management. Our results highlight that shark catches aredominated by threatened species, including the silky sharkCarcharhinus falciformis, scalloped hammerhead Sphyrnalewini, spinner shark Carcharhinus brevipinna, blacktip reefshark Carcharhinus melanopterus and pelagic threshershark Alopias pelagicus, with large proportions beingcaught before they reach sexual maturity. By analysingpatterns across operations, space and time, we identifiedhigh-risk fishing gear, areas and seasons, which can informtargeted and effective management strategies. Our findingsunderscore the need for better fisheries management to haltpopulation declines and implement CITES regulations inIndonesia. These include restrictions on the size of sharksthat can be caught, catch limits or quotas and seasonalclosures, integrated with measures to meet local socioeconomic needs. We provide actionable insights for balancing conservation priorities with fishery economics,contributing to long-term ecological and communityresilience.

Authors: Osmaleli, O; Booth, H; Adrianto, L; Kusumastanto, T; Yulianto, G

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Cambridge University Press
• Journal: Oryx: The International Journal of Conservation
• Pages: 1-12
• Publication date: 2026-08-04
• DOI: 10.1017/S0030605325102160
• EISSN: 1365-3008
• ISSN: 0030-6053
• Language: English
• Keywords: Population; Overfishing; Fishing; Bycatch; Artisanal fishing; Carcharhinus; Threatened species; Fisheries management