Critical habitats for sharks and rays in Asia remain largely unprotected Adriana Gonzalez-Pestana, Peter M. Kyne, Emiliano García-Rodríguez, Ryan Charles, Vanessa Bettcher Brito, et al. Biodiversity and Conservation, 2026 The Asia region harbors exceptional chondrichthyan (shark, ray, and chimaera) diversity but faces intense fishing pressure. The Important Shark and Ray Areas (ISRA) process provides a collaborative, evidence-based framework to identify critical habitats and inform spatial management. We assessed ISRAs across the Bay of Bengal, Southeast Asia, and the Northwest Pacific to characterize their extent, ecological significance, and conservation relevance. We delineated 122 ISRAs spanning ~ 1 million km 2 (~ 3% of the region) across 12 jurisdictions and international waters, encompassing habitats for 121 species (~ 30% of Asia’s chondrichthyans), 76% of which are threatened. Depleted taxa (e.g., giant guitarfishes, Glaucostegidae) were represented, but charismatic megafauna (e.g., Whale Shark Rhincodon typus ) were overrepresented. In contrast, deepwater and freshwater species were underrepresented. Reproductive Areas were the most common ISRA sub-criterion applied (52% of ISRAs), largely in nearshore zones, while areas for range-restricted species were less frequently (18%) identified. Twelve ISRAs overlapped with biodiversity hotspots, including seven in areas of high overall chondrichthyan species richness and five in areas of high range-restricted species richness. Citizen science was the predominant research method used to delineate ISRAs, while fisheries data were underused despite the region’s major fisheries footprint. Geographic coverage was uneven: Indonesia held the most ISRAs (n = 40; 71.7% of ISRA coverage) while eight jurisdictions (e.g., Viet Nam, China, Republic of Korea) lacked ISRAs due to data gaps. Protection shortfalls are stark: MPAs cover < 5% of national waters in 16 jurisdictions (eight with < 1%); 5.4% of ISRA area lies within MPAs; and only 2.8% of ISRA spatial extent overlaps with no-take zones. These results provide a regional foundation to guide spatial planning, prioritize management, close data gaps, and support recovery of Asia’s diverse and imperiled chondrichthyan assemblages.
Spatio-temporal patterns, trends, and oceanographic drivers of whale shark strandings in Indonesia Mochamad Iqba Herwata Putra, Anindya Wirasatriya, Haidar Asyraffauzan, Fahmi, Ismail Syakurachman, et al. Scientific Reports, 2025 Despite the increased international attention to whale shark conservation, their populations remain predominantly depleted due to anthropogenic activities such as fishing, ship collisions, and marine pollution. Reports of whale shark strandings in Indonesia have been increasing in recent years, elevating concerns regarding their well-being and the potential disturbance to their population recovery. However, limited understanding of stranding patterns, trends, and the oceanographic factors potentially driving these events has resulted in efforts focusing primarily on responding to strandings rather than implementing effective mitigation strategies. Using a 13-year stranding dataset (n = 115) obtained from open-access databases, reports, news, and publications, we examined the characteristics of stranding cases in Indonesia, including population demographics, where hotspots occur, and whether their occurrence is related to oceanographic dynamics in the region. Our study highlights significant population-level disturbances, with 70% of stranded individuals being large juveniles (4–7 m). It also documented a positive interannual trend in stranding cases (R² = 0.67, p < 0.01). The southern coast of Java has emerged as a stranding hotspot, with events seasonally associated with strong upwelling, likely related to the seasonal foraging activities of whale sharks in the region. Although natural events were identified as the main factors contributing to whale shark strandings, anthropogenic activities may also play an important role and require further investigation.
Transoceanic dispersal and connectivity of a white shark (Carcharodon carcharias) between southern Africa and Southeast Asia Dylan T. Irion, Oliver J. D. Jewell, Alison V. Towner, Fahmi, G. Christopher Fischer, et al. Wildlife Research, 2025 Population connectivity shapes dispersal, genetic structure, and responses to climate change. Understanding these patterns is vital for identifying threats and improving species management strategies. In May 2024, a fisher from Indonesia with a satellite tag in their possession contacted local conservationists from non-profit organisation Project Hiu. The Project Hiu staff contacted Wildlife Computers with the serial number and successfully located the tag owner. Remarkably, the tag was identified as having been attached to a 390 cm total-length (TL) subadult female white shark (Carcharodon carcharias) in May 2012 in South Africa. Through subsequent investigations, including email correspondence and interviews with the fishers, we have determined that in November 2016, a 473 cm TL female shark (misidentified at the time as a longfin mako shark, Isurus paucus) was captured in longline gear off the coast of Indonesia, Southeast Asia. This remarkable sequence of events marks the first documented movement and connectivity of a white shark between South Africa and Southeast Asia (Indonesia). Over the 4.5 years at liberty, the shark grew in length an estimated 83 cm (18.4 cm per year), supporting previous findings on growth rates for the species. This record of events highlighted both the potential for misidentification and trade of threatened and protected shark species and the increasing benefits of close collaboration with local fishers. This newly discovered link expands our understanding of their wide-ranging connectivity among remote regions, advances our knowledge of their biology and behavior, and underscores the importance of ongoing international research and conservation efforts to protect these apex predators and their habitats.
Ecology, conservation, and future perspective of walking sharks (Hemiscyllium spp.) in Indonesia Fahmi, Y. Putra, S. Oktaviyani, Y. Jutan, A. S. Haris, et al. Pacific Conservation Biology, 2025 Context Walking sharks (Hemiscyllium spp.), native to the Indo–Pacific region, are small, benthic elasmobranchs that exhibit unique fin-assisted locomotion to ‘walk’ along the ocean floor using their fins. Although those species are not primary fishery targets, they face significant threats from fishing, habitat degradation, and exploitation for the international aquarium trade. Conservation efforts have advanced, notably with the full legal protection of all Hemiscyllium species under Indonesia’s Ministerial Decree in 2023. Methods This review examines the ecology, fishery utilisation, and conservation status of Hemiscyllium species, focusing on Hemiscyllium freycineti and Hemiscyllium halmahera in Indonesia. Information were provided from literature reviews, government regulations and policies, interviews, and field observations. Key results Raising public awareness on the protection status of walking sharks are needed in several locations where exploitation is taking place. The development of walking shark tourism can be one of the non-extractive utilisation efforts that may gain economic benefits for local communities. In addition, captive breeding development program can be a solution for population restoration and fulfilling the need for marine ornamental fish industry. Conclusion Efforts to protect walking sharks must encompass comprehensive management strategies that involve local communities, government regulations, and international cooperation. The expansion of Marine Protected Areas (MPAs), habitat restoration, and developing captive breeding programs in Indonesia are essential to the sustainability of the walking shark populations. Implications This paper advocates for integrated conservation strategies, including habitat rehabilitation, adaptive fisheries management, and community-based ecotourism, to ensure the long-term viability of walking shark populations in Indonesia.
Beyond Bycatch: a Socio-Ecological Assessment of Mobulid Rays Fisheries in Banyuwangi Muhammad Salim, Luky Adrianto, Mohammad Kamal, Firmansyah Tawang, Hasan Rizal, et al. Bio Web of Conferences, 2025 Mobulids rays play a crucial role in the pelagic marine ecosystem as filter feeders, regulating nutrient flow. However, they are often caught as bycatch in gillnet fishing gear due to occupying the same niche as other pelagic fish. In Banyuwangi, these fish hold economic value, prompting this research to investigate their bycatch status. Data collection involved daily landing records, direct observations, and interviews with 45 fishers, 4 collectors, and local government representatives over a year (April 2023–March 2024). Results showed mobulid rays accounted for 23.98% of total gillnet fishers’ biomass. Social-Ecological Network Analysis (SENA) indicated mobulid rays, fishers, gillnets, and collectors had high degree values, highlighting their importance. The strongest connection was between fishers and fishing activities, as shown by the highest betweenness value. Generalized Linear Models (GLM) analysis revealed a significant correlation (0.7664) between mobulid ray prices and bycatch. Additionally, bycatch increased when target fish availability declined, indicated by a negative coefficient. This study emphasizes the ecological and economic significance of mobulid rays in Banyuwangi’s fisheries.
Staying Close to Home: Horizontal Movements of Satellite-Tracked Reef Manta Rays Mobula alfredi (Krefft, 1868) in the World’s Largest Manta Sanctuary Edy Setyawan, Abraham B. Sianipar, Ronald Mambrasar, Muhamad Izuan, Abdy W. Hasan, et al. Fishes, 2025 Indonesia is home to significant populations of globally vulnerable reef manta rays (Mobula alfredi) in at least four key regions: Berau, Nusa Penida, Komodo, and Raja Ampat. Despite detailed population studies in each of these regions, little is known about their horizontal movement patterns. Our study used satellite telemetry to investigate reef manta rays’ habitat use and home ranges. A total of 33 manta rays were tagged with SPLASH10F-321A satellite tags across the four regions: Berau (n = 5), Nusa Penida (n = 8), Komodo (n = 6), and Raja Ampat (n = 14), yielding usable data from 25 tags. The rays were tracked for 7 to 118 days (mean ± SD = 50 ± 30) from July 2014 to July 2022. The results showed localized movements, strong residency near tagging sites, and high site fidelity as evidenced by area-restricted search (ARS) behaviors and frequent revisitations. Most manta rays showed restricted home ranges in each region, with no connectivity between regions. Across 25 individuals, the home range (95% utilization distributions) varied significantly, ranging from 19 to 48,294 km2 (mean ± SD = 4667 ± 10,354). These findings offer important insights into the spatial movement patterns of reef manta rays in Indonesia, allowing the formulation of more effective management strategies.
Johnius javaensis, a new species of croaker (Acanthuriformes, Sciaenidae) from the southern coast of Java, Indonesia Bai-an Lin, John J. Pogonoski, Fahmi, Kunto Wibowo, Ning Labbish Chao, et al. Zookeys, 2025 In this study, we describe a newly recognized croaker (Sciaenidae), Johnius javaensis sp. nov. based on five specimens (87–121 mm in standard length) from the southern coast of Java, Indonesia. Specifically, taxonomic reassessment of sciaenids collected from fish markets on the islands of Java, Bali, and Lombok of Indonesia has revealed that specimens previously identified as Johnius heterolepis represent this new species. Johnius javaensis sp. nov. is characterized by five vesicular mental barbels on the chin, 30–32 dorsal-fin rays, seven or eight scale rows below the lateral line; 11 or 12 lower gill rakers, 11 or 12 swim-bladder appendages, and ventral margin of the sagitta head expanded into a distinct convexity. Historically, four Johnius species ( J. amblycephalus , J. fuscolineatus , J. macropterus and J. mannarensis ) were reported to have one mental barbel on the chin. The new species is readily distinguished from all other 33 described Johnius species by possessing five vesicular mental barbels on the chin. A phylogenetic analysis of 21 Johnius species based on the 521-bp COI gene confirms that the new species is placed as a sister species of J. macropterus , based on an average of dissimilarity 8.16%.
