A review of a decade of lessons from one of the world's largest MPAs: conservation gains and key challenges

October 2020

Graeme C. Hays, Heather J. Koldewey, Samantha Andrzejaczek, Martin J. Attrill, Shanta Barley, Daniel T. I. Bayley, Cassandra E. Benkwitt, Barbara Block, Robert J. Schallert, Aaron B. Carlisle, Pete Carr, Taylor K. Chapple, Claire Collins, Clara Diaz, Nicholas Dunn, Robert B. Dunbar, Dannielle S. Eager, Julian Engel, Clare B. Embling, Nicole Esteban, Francesco Ferretti, Nicola L. Foster, Robin Freeman, Matthew Gollock, Nicholas A. J. Graham, Joanna L. Harris, Catherine E. I. Head, Phil Hosegood, Kerry L. Howell, Nigel E. Hussey, David M. P. Jacoby, Rachel Jones, Sivajyodee Sannassy Pilly, Ines D. Lange, Tom B. Letessier, Emma Levy, Mathilde Lindhart, Jamie M. McDevitt-Irwin, Mark Meekan, Jessica J. Meeuwig, Fiorenza Micheli, Andrew O. M. Mogg, Jeanne A. Mortimer, David A. Mucciarone, Malcolm A. Nicoll, Ana Nuno, Chris T. Perry, Stephen G. Preston, Alex J. Rattray, Edward Robinson, Ronan C. Roche, Melissa Schiele, Emma V. Sheehan, Anne Sheppard, Charles Sheppard, Adrian L. Smith, Bradley Soule, Mark Spalding, Guy M. W. Stevens, Margaux Steyaert, Sarah Stiffel, Brett M. Taylor, David Tickler, Alice M. Trevail, Pablo Trueba, John Turner, Stephen Votier, Bry Wilson, Gareth J. Williams, Benjamin J. Williamson, Michael J. Williamson, Hannah Wood & David J. Curnick 

Abstract

“Given the recent trend towards establishing very large marine protected areas (MPAs) and the high potential of these to contribute to global conservation targets, we review outcomes of the last decade of marine conservation research in the British Indian Ocean Territory (BIOT), one of the largest MPAs in the world. The BIOT MPA consists of the atolls of the Chagos Archipelago, interspersed with and surrounded by deep oceanic waters. Islands around the atoll rims serve as nesting grounds for sea birds. Extensive and diverse shallow and mesophotic reef habitats provide essential habitat and feeding grounds for all marine life, and the absence of local human impacts may improve recovery after coral bleaching events. Census data have shown recent increases in the abundance of sea turtles, high numbers of nesting seabirds and high fish abundance, at least some of which is linked to the lack of recent harvesting. For example, across the archipelago the annual number of green turtle clutches (Chelonia mydas) is ~ 20,500 and increasing and the number of seabirds is ~ 1 million. Animal tracking studies have shown that some taxa breed and/or forage consistently within the MPA (e.g. some reef fishes, elasmobranchs and seabirds), suggesting the MPA has the potential to provide long-term protection. In contrast, post-nesting green turtles travel up to 4000 km to distant foraging sites, so the protected beaches in the Chagos Archipelago provide a nesting sanctuary for individuals that forage across an ocean basin and several geopolitical borders. Surveys using divers and underwater video systems show high habitat diversity and abundant marine life on all trophic levels. For example, coral cover can be as high as 40–50%. Ecological studies are shedding light on how remote ecosystems function, connect to each other and respond to climate-driven stressors compared to other locations that are more locally impacted. However, important threats to this MPA have been identified, particularly global heating events, and Illegal, Unreported and Unregulated (IUU) fishing activity, which considerably impact both reef and pelagic fishes.”

Author Affiliations

• Deakin University, Centre for Integrative Ecology

• Zoological Society of London

• Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter

• Hopkins Marine Station, Stanford University

• School of Biological and Marine Sciences, University of Plymouth

• Minderoo Foundation

• School of Biological Sciences, The University of Western Australia

• Centre for Biodiversity and Environment Research, University College London

• Lancaster Environment Centre, Lancaster University

• School of Marine Science and Policy, University of Delaware

• Institute of Zoology, Zoological Society of London

• Hatfield Marine Science Center, Oregon State University

• Department of Life Sciences, Imperial College London

• Earth System Science, Stanford University

• OceanMind Limited, Harwell Innovation Centre

• Department of Biosciences, Swansea University

• Department of Fish and Wildlife Conservation, College of Natural Resources and Environment

• The Manta Trust

• Department of Zoology, University of Oxford

• Department of Integrative Biology, University of Windsor

• School of Ocean Sciences, Bangor University

• Geography, College of Life and Environmental Sciences, University of Exeter

• School of Biological Sciences (M092), The University of Western Australia

• Civil and Environmental Engineering, Stanford University

• Australian Institute of Marine Science, Indian Ocean Marine Research Centre, The University of Western Australia

• Center for Ocean Solutions, Stanford University

• NERC National Facility for Scientific Diving, Scottish Association for Marine Science

• Tritonia Scientific Ltd

• Department of Biology, University of Florida

• P.O. Box 1443, Victoria, Mahé, Seychelles

• Interdisciplinary Centre of Social Sciences (CICS.NOVA), School of Social Sciences and Humanities (NOVA FCSH), NOVA University Lisbon

• School of Life Sciences, University of Warwick

• Conservation Science Group, Department of Zoology, University of Cambridge

• Environment and Sustainability Institute, University of Exeter

• Environmental Research Institute, University of the Highlands and Islands

• Department of Geography, King’s College London

Funded by

• Bertarelli Foundation

• Darwin Foundation

• TeachGreen

• Garfield Weston Foundation

• Overseas Territories Environment Programme

• Darwin Initiative

• Selfridges & Co.

• JSF Pollitzer Charitable Trust

• The Rufford Foundation

• Ernest Kleinwort Charitable Trust

• Chagos Conservation Trust