Impact of sea level rise on the 10 insular biodiversity hotspots

• Published in: Global ecology and biogeography Vol. 23; no. 2; pp. 203 - 212
• Main Authors: Bellard, Céline, Leclerc, Camille, Courchamp, Franck
• Format: Journal Article
• Language: English
• Published: Oxford Blackwell Publishing Ltd 01.02.2014; John Wiley & Sons Ltd; Blackwell; Wiley Subscription Services, Inc
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Biodiversity; Biodiversity conservation; Biodiversity hotspots; Biological and medical sciences; Climate change; Climatology. Bioclimatology. Climate change; Earth, ocean, space; Ecosystems; Endemic species; endemic-area relationship; Exact sciences and technology; External geophysics; Fundamental and applied biological sciences. Psychology; General aspects; Global warming; Habitat loss; islands; Mammals; Marine; Meteorology; Reptiles; Reptiles & amphibians; Sea level; Sea level rise; Species extinction; Synecology; PSE, New Zealand; ISW, Indian Ocean, Madagascar; ISEW, Pacific, New Caledonia; ISW, Indian Ocean; ASW, Caribbean Sea; ISEW, Philippines; INW, Japan; Biodiversity hotspots; Endemic species; Hot spot; Biogeography; Ecology; Biodiversity; Sea level; Island; sea level rise; Dynamical climatology; Climate change; islands; endemic―area relationship
• ISSN: 1466-822X; 1466-8238; 1466-822X
• DOI: 10.1111/geb.12093

Aim Despite considerable attention to climate change, no global assessment of the consequences of sea level rise is available for insular ecosystems. Yet, over 180,000 islands world-wide contain 20% of the world's biodiversity. We investigated the consequences of sea level rise for the 10 insular biodiversity hotspots world-wide and their endemic species. This assessment is crucial to identify areas with the highest risk of inundation and the number of endemic species at risk of potential extinction. Location Ten insular biodiversity hotspots including the Caribbean islands, the Japanese islands, the Philippines, the East Melanesian islands, Polynesia-Micronesia, Sundaland, Wallacea, New Caledonia, New Zealand and Madagascar and the Indian Ocean islands (i.e. 4447 islands). Methods We investigated four scenarios of projected sea level rise (1, 2, 3 and 6 m) on these islands. For each scenario, we assessed the number of islands that would be entirely and partially submerged by overlying precise digital elevation model and island data. We estimated the number of endemic species for each taxon (i.e. plants, birds, reptiles, mammals, amphibians and fishes) potentially affected by insular habitat submersion using the endemic–area relationship. Results Between 6 and 19% of the 4447 islands would be entirely submerged under considered scenarios (1–6 m of sea level rise). Three hotspots displayed the most significant loss of insular habitat: the Caribbean islands, the Philippines and Sundaland, representing a potential threat for 300 endemic species. Main conclusions With the current estimates of global sea level rise of at least 1 m by 2100, large parts of ecosystems of low-lying islands are at high risk of becoming submerged, leading to significant habitat loss world-wide. Therefore, the threat posed by sea level rise requires specific policies that prioritize insular biota on islands at risk as a result of near future sea level rise.