Only One Percent of Important Shark and Ray Areas in the Western Indian Ocean Are Fully Protected From Fishing Pressure

The Western Indian Ocean (WIO) is known for its high diversity of chondrichthyans (sharks, rays, and chimaeras). However, intense fishing pressure has led to severe population declines and local extinctions of several species. The Important Shark and Ray Area (ISRA) process is a collaborative, evidence-based approach used to identify critical habitat for chondrichthyans. We analysed ISRAs across the WIO to quantify the diversity of research methods used to identify them, evaluate spatial overlap with designated marine protected areas (MPAs), model the influence of several species- and jurisdiction-specific variables on ISRA delineation, and explore the importance of incorporating unpublished data into the delineation process. In total, 125 ISRAs (covering > 2.8 million km<sup>2</sup>; ~10% of total regional surface area) were identified within the WIO from surface waters to ~2000 m depth. These ISRAs contain over one-third (<i>n</i> = 104, 39%) of the 270 chondrichthyan species reported from the region, with 76% being threatened with extinction according to the IUCN Red List of Threatened Species. The underlying evidence supporting ISRA identification was primarily drawn from relatively inexpensive research methods, such as visual census (25%) or fish-market/landing site surveys (22.6%), as well as citizen science (9.5%). Incorporating unpublished records substantially increased the frequency of ISRA delineation, leading to expanded taxonomic and geographic coverage. Still, the full dataset was influenced by the same biases as the published record, tending to favour large-bodied, wide-ranging, and shallow-dwelling species. Only 7.1% of ISRAs are within designated MPAs, with just 1.2% in fully protected no-take areas. The highest no-take overlap occurs in the Seychelles and Chagos Archipelago. These findings highlight the shortfalls in spatial protection of chondrichthyan habitats, but also present a strategic opportunity for policy-makers and resource managers to improve current MPA coverage and meet their commitments under international agreements, such as the Global Biodiversity Framework.

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Journal
Ecology and Evolution
Published
2026-01-01
DOI
https://doi.org/10.1002/ece3.72690
Primary Topic
Ichthyology and Marine Biology
Type
article
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0.00

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article

Only One Percent of Important Shark and Ray Areas in the Western Indian Ocean Are Fully Protected From Fishing Pressure

Simon James Pittman, Alireza Rastgoo, Ornella C. Weideli, Lauren Peel et al.
Ecology and Evolution
Ichthyology and Marine Biology
article

Only One Percent of Important Shark and Ray Areas in the Western Indian Ocean Are Fully Protected From Fishing Pressure

Simon James Pittman, Alireza Rastgoo, Ornella C. Weideli, Lauren Peel, Ehab Eid, John Nevill, Robert Bullock, Nico Fassbender, Estelle Crochelet, RH Bennett, Emiliano García‐Rodríguez, Irthisham Zareer, Andrew Willson, Alissa Barnes, David van Beuningen, Livi Wilson, Stela M. C. Fernando, Darren J. Coker, Simon Hilbourne, C. Cánovas-Pérez, Isabel Chaúca, Divya Karnad, Lea Palm, Nadeem Nazurally, Hamid Reza Bargahi, Nakia Cullain, Christoph A. Rohner, Joanna L. Harris, Jennifer Olbers, Dareen Almojil, Jesse E. M. Cochran, Ginevra Boldrocchi, Tessa N. Hempson, Andrew J. Temple, Michael L. Berumen, Stephanie K. Venables, Guy M. W. Stevens, S Behzadi, Ashlie J. McIvor, Ajay DAYARAM Nakhawa, Lennart Vossgaetter, Anna L. Flam, Bradley J. Peterson, Kaitlyn M. Zerr, Trisha Gupta, Ryan Daly, Samantha Andrzejaczek, Bigeyo Kuboja, Michelle Carpenter, Jennifer V. Schmidt, Théophile L. Mouton, Alec B. M. Moore, Elspeth M. Strike, Joshua M. Rambahiniarison, Royale S. Hardenstine, Leigh De Necker, David P. Robinson, Hashim Manjebrayakath, Shikha Rahangdale, Camrin D. Braun, S.T. Fennessy, Adriana González‐Pestana, Bernadine I. Everett, Anna Koester, Badru Hagy, Brittney J. Scannell, Omar Abdulkadir Mahadalle, Raquel Lubambo Ostrovski, Eloise B Richardson, Aaron B. Carlisle, Nathan Perisic, Eleanor Brighton, Giri Bhavan Sreekanth, Isabel Silva, Stella Diamant, Rima Jabado, Haleh Ali Abedi, Taylor K. Chapple, Arzucan Askin, Filippo Bocchi, Svetlana Barteneva‐Vitry, Tamaryn J. Sawers, Muktha Menon, Shoba Joe Kizhakudan, Gill Braulik, David M. P. Jacoby, Igbal S. Elhassa, David A. Ebert, Meral Hafeez, Viktor Nunes Peinemann, Alexander Kattan, Aymeric Bein, Brittany Finucci, Simon J. Pierce, Ryan Charles, Idrees Babu K K, Melita A. Samoilys, Mohsen Rezaie‐Atagholipour, Arnault R. G. Gauthier, Julia L. Y. Spaet, Hua Hsun Hsu, Kalli Valappil Akhilesh, Reem K. Almealla, Sébastien Jaquemet, Frances K. P. Budd, Ivor D. Williams, Taryn S. Murra, Baraka L. Kuguru, Collin T. Williams, Daniel Mateos‐Molina, David J. Curnick, Luis Silva, Jessica Harvey‐Carroll, Alison A. Kock, Kaitlyn A. O'Toole, Peter M. Kyne, Lauren E. Nelso, Asia O. Armstrong, Peter Gausman, Jessica L. A. Haines, Geremy Cliff, Avik A. Banerjee, Nor D. Ibrahim, Giulia F. A. Donati, Christophe Mason‐Parker, Jadiyde Solonomenjanahary, James S. E. Lea, Chantel Elston, Boaz Kaunda‐Arara, Amanda Batlle‐Morera, Johann Mourier, Mahmoud M. S. Farrag
article en

Abstract

The Western Indian Ocean (WIO) is known for its high diversity of chondrichthyans (sharks, rays, and chimaeras). However, intense fishing pressure has led to severe population declines and local extinctions of several species. The Important Shark and Ray Area (ISRA) process is a collaborative, evidence-based approach used to identify critical habitat for chondrichthyans. We analysed ISRAs across the WIO to quantify the diversity of research methods used to identify them, evaluate spatial overlap with designated marine protected areas (MPAs), model the influence of several species- and jurisdiction-specific variables on ISRA delineation, and explore the importance of incorporating unpublished data into the delineation process. In total, 125 ISRAs (covering > 2.8 million km<sup>2</sup>; ~10% of total regional surface area) were identified within the WIO from surface waters to ~2000 m depth. These ISRAs contain over one-third (<i>n</i> = 104, 39%) of the 270 chondrichthyan species reported from the region, with 76% being threatened with extinction according to the IUCN Red List of Threatened Species. The underlying evidence supporting ISRA identification was primarily drawn from relatively inexpensive research methods, such as visual census (25%) or fish-market/landing site surveys (22.6%), as well as citizen science (9.5%). Incorporating unpublished records substantially increased the frequency of ISRA delineation, leading to expanded taxonomic and geographic coverage. Still, the full dataset was influenced by the same biases as the published record, tending to favour large-bodied, wide-ranging, and shallow-dwelling species. Only 7.1% of ISRAs are within designated MPAs, with just 1.2% in fully protected no-take areas. The highest no-take overlap occurs in the Seychelles and Chagos Archipelago. These findings highlight the shortfalls in spatial protection of chondrichthyan habitats, but also present a strategic opportunity for policy-makers and resource managers to improve current MPA coverage and meet their commitments under international agreements, such as the Global Biodiversity Framework.

Ecology and EvolutionVol. 16(1)
Andrews University (US), University of Insubria (IT), New York University Abu Dhabi (AE), Ministry of Economy (MK), Centre National de la Recherche Scientifique (FR), University of Tasmania (AU), Dalhousie University (CA), Oregon Department of Fish and Wildlife (US), WWF Colombia (CO), Zoological Society of London (GB), Wildlife Conservation Society (US), South African National Parks (ZA), National Sun Yat-sen University (TW), Ifremer (FR), University of Cape Town (ZA), Universität Hamburg (DE), Bangor University (GB), University of the Sunshine Coast (AU), The University of Western Australia (AU), University of Bremen (DE), Al-Azhar University (EG), Université de Montpellier (FR), Princeton University (US), Rhodes University (ZA), Hokkaido University (JP), University of Victoria (CA), University of Eldoret (KE), University of Exeter (GB), University of Cambridge (GB), University of Reunion Island (RE), Universidad Científica del Sur (PE), Council of Agriculture (TW), Pwani University (KE), Leibniz Centre for Tropical Marine Research (DE), Swiss Federal Institute for Forest, Snow and Landscape Research (CH), Dijlah University College (IQ), Somali National University (SO), University of Manchester (GB), Charles Darwin University (AU), University of Technology Bahrain (BH), Lúrio University (MZ), Ashoka University (IN), University of Oxford (GB), The Ocean Foundation (US), Centre Hospitalier Universitaire de La Réunion (RE), University of Hormozgan (IR), Marine Megafauna Foundation (US), Maldives National University (MV), Tanzania Fisheries Research Institute (TZ), Smithsonian Marine Station (US), Northwest Indian Fisheries Commission (US), Central Coastal Agricultural Research Institute (IN), The Dia Foundation for Research on Ageing Societies (JP), South African Association for Marine Biological Research (ZA), International Union for Conservation of Nature (United States) (US), International Union for Conservation of Nature (United Kingdom) (GB), Kootenay Association for Science & Technology (CA), Bayer (Australia) (AU), Naval Physical & Oceanographic Laboratory (IN), Saudi Heart Association (SA), Save Our Seas Foundation (CH), Akbaraly Foundation (MG), Development Fund (NO), French National Agency for Water and Aquatic Environments (FR), Mogadishu University (SO), Private University in the Principality of Liechtenstein (LI), Coastal Oceans Research and Development in the Indian Ocean (KE), ARC Centre of Excellence for Coral Reef Studies (AU), Shahab Danesh University (IR), Department of Fisheries (ZM), Ministère de l’Environnement et du Développement Durable (SN), University of Bahri (SD), Marine Biodiversity Exploitation and Conservation (FR), Danish Ministry of Food, Agriculture and Fisheries (DK), Wildlife Conservation Society India (IN), DMG (Germany) (DE), University of Seychelles (SC), Umkhuseli Innovation and Research Management (ZA), International Union for Conservation of Nature (CH), Al Nahdha Hospital (OM), Instituto de Investigação Agrária de Moçambique (MZ), Institut de Recherche pour le Développement (FR), Royal Society for the Conservation of Nature (JO), National Institute of Water and Atmospheric Research (NZ), Stony Brook University (US), Swiss Federal Institute of Aquatic Science and Technology (CH), Woods Hole Oceanographic Institution (US), Lancaster University (GB), University of Mauritius (MU), South African Institute for Aquatic Biodiversity (ZA), King Abdullah University of Science and Technology (SA), Island Conservation Society (SC), Universidad de Murcia (ES), Alps Electric (Japan) (JP), James Cook University (AU), University of Delaware (US), University of Gothenburg (SE), Los Angeles Mission College (US), University of Plymouth (GB), Central Marine Fisheries Research Institute (IN), Ruhr University Bochum (DE), Persian Gulf University (IR), University of KwaZulu-Natal (ZA), Moss Landing Marine Laboratories (US), Nelson Mandela University (ZA), Silliman University (PH)
Wildlife Conservation Society, National Sun Yat-sen University, Johns Hopkins University, National Institute of Water and Atmospheric Research, Oregon State University, New York University Abu Dhabi, San José State University, Iranian Fisheries Science Research Institute, Universidad Científica del Sur, York University, University of Exeter, University of St Andrews, University of Oxford, University of Tasmania, Indian Council of Agricultural Research, James Cook University, University of the Sunshine Coast, Charles Darwin University, Sun Yat-sen University, Dalhousie University, King Abdullah University of Science and Technology, Inyuvesi Yakwazulu-Natali, Università degli Studi dell'Insubria, Universität Hamburg, Göteborgs Universitet, University of Cape Town, Save Our Seas Foundation, Université de La Réunion, Central Marine Fisheries Research Institute, Al-Azhar University, Directorate for Biological Sciences, Centre of Excellence for Coral Reef Studies, Australian Research Council
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Ichthyology and Marine Biology
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