Jesse E. M. Cochran, Ryan Charles, Andrew J. Temple, Peter M. Kyne, Emiliano García‐Rodríguez, Adriana González‐Pestana, Amanda Batlle‐Morera, Théophile L. Mouton, Asia O. Armstrong, Christoph A. Rohner, Darren J. Coker, Royale S. Hardenstine, Alexander Kattan, Ashlie J. McIvor, Viktor Nunes Peinemann, Kaitlyn A. O'Toole, Lea Palm, Eloise B Richardson, Kalli Valappil Akhilesh, Haleh Ali Abedi, Reem K. Almealla, Dareen Almojil, Samantha Andrzejaczek, Arzucan Askin, Avik A. Banerjee, Hamid Reza Bargahi, Alissa Barnes, Svetlana Barteneva‐Vitry, S Behzadi, Aymeric Bein, RH Bennett, Filippo Bocchi, Ginevra Boldrocchi, Gill Braulik, Camrin D. Braun, Eleanor Brighton, Frances K. P. Budd, Robert Bullock, C. Cánovas-Pérez, Aaron B. Carlisle, Michelle Carpenter, Taylor K. Chapple, Isabel Chaúca, Geremy Cliff, Estelle Crochelet, Nakia Cullain, David J. Curnick, Ryan Daly, Leigh De Necker, Stella Diamant, Giulia F. A. Donati, David A. Ebert, Ehab Eid, Igbal S. Elhassa, Chantel Elston, Bernadine I. Everett, Mahmoud M. S. Farrag, Nico Fassbender, S.T. Fennessy, Stela M. C. Fernando, Brittany Finucci, Anna L. Flam, Peter Gausmann, Arnault R. G. Gauthier, Giri Bhavan Sreekanth, Trisha Gupta, Meral Hafeez, Badru Hagy, Jessica L. A. Haines, Joanna L. Harris, Jessica Harvey‐Carroll, Tessa N. Hempson, Simon Hilbourne, Hua Hsun Hsu, Nor D. Ibrahim, David M. P. Jacoby, Sébastien Jaquemet, Idrees Babu K K, Divya Karnad, Boaz Kaunda‐Arara, Shoba Joe Kizhakudan, Alison A. Kock, Anna Koester, Bigeyo Kuboja, Baraka L. Kuguru, James S. E. Lea, Omar Abdulkadir Mahadalle, Hashim Manjebrayakath, Christophe Mason‐Parker, Daniel Mateos‐Molina, Muktha Menon, Alec B. M. Moore, Johann Mourier, Taryn S. Murra, Ajay DAYARAM Nakhawa, Nadeem Nazurally, Lauren E. Nelso, John Nevill, Jennifer Olbers, Raquel Lubambo Ostrovski
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 2 ; ~10% of total regional surface area) were identified within the WIO from surface waters to ~2000 m depth. These ISRAs contain over one‐third ( n = 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.