"<h2>Reef-Dependent Population</h2>In the Western Indian Ocean (WIO) region, 48 million people benefit from coral reefs, including 21.5 million people who are likely highly dependent on reefs for their food or livelihood.(Estimated using WorldPop and World Vector Shoreline. People within 30 km of reefs and 10 km of the coast were considered \"highly dependent,\" while those within 100 km of reefs \"benefit.\")&nbsp;"

"<h2>Tourism</h2>Coral reef-associated tourist expenditure in the WIO region is valued at $830 million annually. This includes on-reef recreation (snorkeling, diving, recreational fishing, glass-bottom boat tours, etc.) as well as reef-adjacent benefits (such as white, sandy beaches and sheltered waters)."

Value

Vulnerability

Infrastructure

Habitat

Value and Importance of Coral Reefs

"About 6% of the world's coral reefs are in the WIO region. Different sources offer different figures for the total area of reef cover: Source &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Area (km²)&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Global Share <a href=\"https://data.unep-wcmc.org/datasets/1\" rel=\"noopener noreferrer\" target=\"_blank\">Global Distribution of</a>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;9,576&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;6.4%<a href=\"https://data.unep-wcmc.org/datasets/1\" rel=\"noopener noreferrer\" target=\"_blank\">Coral Reefs (UNEP-WCMC)</a>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<a href=\"https://gcrmn.net/products/reports/\" rel=\"noopener noreferrer\" target=\"_blank\">Global Coral Reef Monitoring</a>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;15,180&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;5.8%<a href=\"https://gcrmn.net/products/reports/\\\" rel=\"noopener noreferrer\" target=\"_blank\">Network (GCRMN) Report</a>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 40.5 percent of WIO coral reefs are located within marine protected areas; 2 percent in “Fully or Highly Protected” areas."

"<h2>Mangroves</h2>The WIO region possesses about 5.3% of the world's mapped mangroves. Between 1996 and 2016, the region lost roughly 4% of its mangrove area (a net loss of 300 km²). This net change included both 421 km² of loss and 121 km² of gain. As of 2016, the region had 7,253 km² of mangrove forest."

Ecosystems

Protected Areas

Coral Reefs, Mangroves, and Protection

"<h2>Local Threats</h2>Local activities and pollution threaten 75% of reefs in the WIO region, with overfishing being the most pervasive threat. Coastal development, land-based sources of pollution are also important threats in many locations."

"<h2>Coral Bleaching Conditions</h2>In the WIO there were major bleaching events in 1998 and 2016. Projections suggest that most coral reefs will experience severe coral bleaching conditions at least twice per decade by the 2030s, and annually by the 2040s."

"<h2>Ocean Acidification</h2>By the 2040s, most reefs in the WIO region will be situated in conditions considered marginal for coral growth, based on ocean acidity and the availability of aragonite. By the 2070s, almost all reefs will be in areas rated poor."

Habitats

Local Threats

Global Threats

Local and Global Threats to Coral Reefs

"<h2>Live Hard Coral Cover</h2>Live Hard Coral Cover. This time-series clearly illustrates the impacts of the two major bleaching events on coral cover in the region (1998 and 2016), each characterized by downward trajectories following bleaching. Promisingly, however, it also demonstrates the capacity for reefs to recover after bleaching, if there is enough time between major disturbances. The <a href=\"https://gcrmn.net/resource/status-coral-reef-western-indian-ocean-2017/\" rel=\"noopener noreferrer\" target=\"_blank\" style=\"color: rgb(0, 0, 0);\">2017 GCRMN Regional Report for the WIO</a> included some data which was not available for this global GCRMN analysis. The regional report suggests that live coral cover in the 1980’s and 1990’s was as high 40%, and that the reefs have not fully recovered to conditions prior to the 1998 bleaching event. There has also been a clear change in coral community structure, with <a href=\"https://gcrmn.net/resource/status-coral-reef-western-indian-ocean-2017/\" rel=\"noopener noreferrer\" target=\"_blank\" style=\"color: rgb(0, 0, 0);\">loss of susceptible coral species and loss of diversity</a>, though some acclimation and/or adaptation of corals to warming may have occurred following multiple bleaching events."

"<h2>Algae Cover</h2>The trend in algae cover over the last 27 years is less clear than that of hard coral cover, largely due to fewer available data and inconsistencies in monitoring. Overall, algae have remained stable at ~27%, with small increases in the late 1990s and 2000s, corresponding to declines in coral cover."

"Modeled cover of live hard coral cover (left) and algae (right) for the South Asia region. The solid line represents the predicted marginal mean and ribbons represent 80% (lighter shade) and 95% (darker shade) credible intervals. Grey areas of the temporal series represent times for which no observed data were available."

"<h1>Summary</h1> The WIO region includes about 6 percent of the world’s coral reefs, of which 40 percent are in MPAs (a relatively high percentage), though only 2 percent are in fully or highly protected areas. Reefs in many parts of the region have shown reasonable recovery in the period between the major bleaching events of 1998 and 2016. This provides some hope that with adequate measures to minimize local threats reefs in climatically favorable areas may have a chance to keep up with warming conditions. But the increasing frequency and intensity of heat stress and intensification of local pressures may overwhelm such capacities for adaptation unless strong actions are taken to reduce all threats. Increasing the extent of fully and highly protected areas could help reduce local threats For more detail on the WIO region and its subregions see the GCRMN global report <a href=\"https://gcrmn.net/2020-report/\" rel=\"noopener noreferrer\" target=\"_blank\" style=\"color: rgb(0, 0, 0);\">Status of Coral Reefs of the World: 2020</a>, and the <a href=\"https://gcrmn.net/resource/status-coral-reef-western-indian-ocean-2017/\" rel=\"noopener noreferrer\" target=\"_blank\" style=\"color: rgb(0, 0, 0);\">GCRMN 2017 regional report for the Western Indian Ocean</a>."

The Western Indian Ocean region includes sovereign states along the African mainland (Somalia, Kenya, Tanzania, Mozambique, South Africa), island states (Mauritius, Madagascar, Comoros, Seychelles), and overseas territories (Reunion, France). 

Coral Reefs: Western Indian Ocean

Importance, status and outlook for coral reefs in the Western Indian Ocean (WIO) region

Resource Watch

Coral Reefs: Western Indian Ocean

Importance, status and outlook for coral reefs in the Western Indian Ocean (WIO) region

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