Click on the map below to explore a story from Reefs at Risk Revisited, about threats to reefs and efforts to protect them.
Zaki’s Reef, in the Red Sea off the coast of Egypt, is adjacent to a desert with one of the highest evaporation rates in the world, where conditions result in extremely high salinities and fluctuations in water temperature. Zaki’s Reef is particularly threatened by local pressures from overfishing, shipping, and coastal development. After a major oil spill and a bleaching event in 2005, there was a marked decrease in the health of the reef. However, data from 2008 point to signs of recovery, including a decline in coral disease and an increase in new coral growth. The continued existence of reefs in this region demonstrates that certain corals can survive under extreme conditions, and suggests that reef ecosystems may be capable of rebounding and adapting to new stressors.
Coral reefs in the Persian Gulf have evolved to survive some of the highest temperatures and salinities on Earth. However, they are threatened by massive coastal and offshore development, which has caused a serious decline in associated habitats, species, and overall ecosystem function in the region. The key to stemming the decline from overdevelopment lies in greater regional-level coordination and a longer-term, holistic outlook for the gulf as an ecosystem. These approaches will help to ensure both the ecological and economic sustainability of the gulf into the future.
Tanzania, on Africa’s east coast, is home to an extensive network of coral reefs that support major fishing and tourism industries. However, Tanzania is also the only country in Africa where dynamite fishing still occurs on a large scale. This devastating form of fishing first appeared in the 1960s, and by the mid-1990s had become a serious problem. A high-profile national campaign in the late 1990s nearly eradicated blast fishing between 1997 and 2003; however, inadequate prosecution and minimal penalties levied against dynamiters have allowed this illegal practice to re-emerge and expand. Increased pressure, both domestically and internationally, is needed to create the political will necessary to once again halt this short-sighted and unsustainable practice.
The vast reef systems of the Chagos Archipelago are the most geographically isolated in the Indian Ocean and are far from most human influence, other than a large military base in the south. Chagos lost about 80 percent of its shallow and soft corals following severe bleaching in 1998.90 Since then, and despite further bleaching in 2003 and 2005, there has been a remarkable recovery, highlighting the potential resilience of reefs to climate change where other human stresses are reduced or absent.
Pulau Seribu is a group of 105 islands surrounded by diverse coral reef ecosystems off Jakarta, Indonesia. While proximity to Jakarta brings economic benefits to the islands, it also exposes the marine habitat to intensive human activities including blast and cyanide fishing, trawling, solid waste, and sediment. In 2002, the local government, community members, and NGOs started developing management measures to assist reef recovery, with encouraging results. Surveys carried out by the Indonesian Coral Reef Foundation (TERANGI) in 2007 showed increased coral cover in many areas. In addition, ornamental fish species that had previously disappeared due to overharvesting were observed on the reef. These management measures, implemented over the last nine years, encourage optimism for threatened reefs worldwide.
Many larger reef fish such as groupers and snappers travel long distances to spawn in dense aggregations. Fishers often target such gatherings, rapidly decimating the population and simultaneously reducing the natural restocking of the reefs with new fish larvae. Preventing fishing on these spawning aggregations is a considerable challenge, but in Wakatobi National Park a growing awareness of declining fish populations has helped to fuel community-led initiatives, in collaboration with park authorities, to close fishing on what some locals have termed “fish banks.” These measures have reversed the decline in the number of spawning groupers and snappers, with the expectation that recovery of entire populations will follow.
Culion Island, in the southwestern Philippines, is surrounded by diverse reefs. In coastal villages, rapid growth in population, heavy dependence on coastal resources, and destructive fishing practices have resulted in the near collapse of reef habitat and fisheries. To address these concerns, PATH Foundation Philippines started the Integrated Population and Coastal Resource Management (IPOPCORM) initiative to empower communities to implement family planning activities simultaneously with community-led coastal conservation and alternative livelihood strategies. This approach has led to increased community well-being, greater food security, and an improvement in the health of Culion’s reefs.
Australia’s Great Barrier Reef is the world’s largest coral reef ecosystem and is almost completely contained within a marine protected area. Despite recognition that it is one of the world’s best-managed reefs, its long-term outlook is poor due to the anticipated impacts of climate change (that is, warming and acidifying seas). As in other areas, climate-related threats can be compounded by local threats originating outside the park, including coastal development, mining, and agricultural runoff, which cause poor-quality water to drain into the marine park. In response, national and state governments have developed a coastal water quality protection plan, and the Great Barrier Reef Marine Park Authority has launched the Reef Guardian program to build resilience into the reef ecosystem in the face of climate change.
The Republic of Palau, in the western Pacific Ocean, is surrounded by more than 525 sq km of coral reefs. Construction of the recently completed 85-km “Compact Road” around Palau’s largest island, Babeldaob, led to widespread clearing of forests and mangroves, causing soils to erode into rivers and coastal waterways, damaging coral reefs, seagrass beds, and freshwater resources. To better understand the impact of the changing landscape on the marine environment, the Palau International Coral Reef Center (PICRC) conducted a study that revealed that the degradation of reefs was a direct result of land-based sediments. After PICRC presented these findings to local communities, the governing body of Palau’s Airai State instituted a ban on the clearing of mangroves. Communities, local governments, and NGOs also joined together to form the Babeldaob Watershed Alliance, a forum for developing land management plans and establishing collective conservation goals.
The United States recently proposed plans to expand military operations on the U.S. territory of Guam with the construction of new bases, an airfield, a deep-water port, and facilities to support 80,000 new residents (a 45 percent increase over the current population). Dredging the port alone will require removing 300,000 square meters of coral reef. In February 2010, the U.S. Environmental Protection Agency rated the plans as “Environmentally Unsatisfactory” and suggested revisions to upgrade existing wastewater treatment systems and lessen the proposed port’s impact on the reef. At the time of publication, construction had not started pending resolution of these issues.
Located off the island of New Britain, Papua New Guinea, the rich marine habitat of Kimbe Bay supports local economic and cultural life. However, Kimbe Bay’s reefs are particularly threatened by land pollution, overfishing, and bleaching. In response, local communities and government agencies are working together with The Nature Conservancy to design and implement one of the first marine protected area (MPA) networks that incorporates both socioeconomic considerations and the principles of coral reef resilience to climate change, such as biological connectivity (to promote the exchange of larvae between reefs). The lessons learned from this pilot MPA will help to give coral reefs and associated ecosystems around the world a better chance to survive climate change.
Prony Bay in southern New Caledonia, located 1,200 km east of Australia, is renowned for its exceptional reef communities. In 2005, the nickel mining corporation Vale Inco NC agreed to fund the transplantation of corals to compensate for reef habitat lost during the construction of its port. After three years, 80 percent of the individual coral transplants were still alive and in good health. Fish have also colonized the restored site and the surrounding reef community appears to be denser and more diverse. The Prony Bay example shows how with adequate resources and favorable conditions, such transplantation may offer a successful last resort to save an otherwise certain loss of reef habitat.
The Namena Marine Reserve surrounds the 1.6 km long island of Namenalala and one of Fiji’s most pristine reef ecosystems, the Namena Barrier Reef. In the mid-1980s, community members noticed drastic declines in fish populations on the reef due to intensive commercial fishing. As a result, local chiefs and community leaders led a movement against commercial fishing that ultimately resulted in the establishment of a locally managed marine area (LMMA) network. Managing the LMMA emphasizes an ecosystem-based management approach while also protecting traditional fishing practices and creating tourism revenue to support a scholarship fund for local children. The reefs are recovering, providing an invaluable lesson in how community action combined with management knowledge can provide multiple benefits.
Rose Atoll is a National Wildlife Refuge located in the South Pacific within the U.S. territory of American Samoa. In 1993, a 275-ton fishing vessel ran aground on Rose Atoll’s shallow reef. Subsequent monitoring revealed that the disintegration and corrosion of the ship was releasing dissolved iron into surrounding waters, stimulating growth of cyano-bacteria (blue-green algae) on the reefs. In response, the U.S. government removed the remaining debris, but at a substantial cost. The reefs are now recovering rapidly. This success was due largely to Rose Atoll’s status as an actively managed protected area, in combination with sufficient funds, effort, and expertise to monitor the damage and recovery. In 2009 the U.S. established Rose Atoll as a Marine National Monument in January 2009, thus banning commercial fishing within 50 nautical miles (90 km) of the atoll.
The Line Islands, a chain of a dozen atolls and coral islands in the central Pacific Ocean, are home to some of the most remote and pristine coral reefs on Earth. The uninhabited atolls of Millennium and Kingman provide a glimpse of coral reefs before human impacts, including incredible coral formations and an abundance of predators like sharks and groupers. The populated atolls of Tabuaeran and Kiritimati and the island of Teraina, on the other hand, show a decline in reef health due to overfishing and pollution. Recent studies of the atolls reveal a strong association between increasing human population and ecosystem decline. They show how human influence is the most paramount determinant of reef health, and add valuable evidence to the growing understanding of how minimizing human impacts on reefs may increase their resilience to global climate change.
Caño Island Biological Reserve and Cocos Island are both located off the Pacific coast of Costa Rica. Two severe El Niño–Southern Oscillation (ENSO) warming events in the 1980’s and 1990’s caused widespread coral bleaching and mass mortality on the reefs, compounded by other natural disturbances, such as phytoplankton blooms. Scientists predicted that the recovery of live coral cover would take decades, and that the recovery of the reefs’ framework would take centuries. But today, both reefs are recovering much faster than expected. Working in their favor, both areas are protected and no-take zones. Cocos Island, which has a much lower human influence than Caño Island, has seen an even higher rate of recovery. This suggests that protecting reefs from localized human threats can make reefs more resilient in the face of climate change.
The Mesoamerican Reef—the largest continuous reef in the Western Hemisphere—is threatened by overfishing, coastal development, agricultural runoff, and warming seas. In 1998, a mass coral bleaching event caused significant coral mortality on the reef. However, some coral species in areas where the reef and surrounding waters were relatively free of sediment were able to recover and grow normally within two to three years, while corals living with excessive local human pressures were not able to fully recover even eight years after the event. This pattern suggests that reducing local threats will also help corals to be more resilient in the face of rising sea temperatures.
Southeast Florida’s extensive reefs lie close to three major sea ports and the damage from large boat groundings and dragging anchor cables can be considerable. In 2008, the U.S. Coast Guard relocated the Port Everglades anchorage , and since then no groundings have occurred in the vicinity. Building upon this success, resource management organizations are now working to address the Port of Miami anchorage area, which is located directly over a reef, Working with a variety of stakeholders has provided government management agencies with extra “eyes and ears” on the reefs as well as additional expertise and insight, allowing for a level of management and monitoring which would not otherwise be possible with limited agency resources.
La Caleta National Marine Park, located on the southern coast of the Dominican Republic draws numerous divers every year. However, for years the social and economic drivers of overfishing and pollution were not addressed, leading to the deterioration of the La Caleta reef. In response, Reef Check Dominican Republic has launched an initiative to help La Caleta’s residents participate in park management, while also promoting sustainable alternatives to fishing through dive tourism. These measures have already led to an increase in fish abundance and live coral cover in the Park, which is anticipated to attract more tourists. Empowering local communities represents a new model for Dominicans to sustainably manage, and benefit from, their coastal ecosystems.
Tobago’s Buccoo Reef, located inside the Buccoo Reef Marine Park (BRMP) at the island’s southwest tip, is integral to Tobago’s tourism-driven economy and also protects the coastline from erosion and storm damage. However, tourism and residential development, combined with limited enforcement of park regulations, have resulted in the deterioration of Buccoo Reef’s health. Enforcement of the park’s no-fishing regulations, financed through collection of park entrance fees, would improve conditions on the reef. Treating sewage, re-routing wastewater outfalls, and improving watershed management would all significantly improve water quality. While these management policies would involve additional short-term costs, the longer-term economic and ecological benefits would far outweigh the initial investments.
Brazil’s Abrolhos Bank contains some of the largest and richest coral reefs in the South Atlantic. In the last 20 years, the area’s coastline has experienced increased tourism, urbanization, and large-scale agriculture, leading to discharge of untreated waste and contamination of the region’s reefs. As a result, the prevalence of coral disease has dramatically escalated off the Brazilian coastline in recent years. Furthermore, studies have linked the global proliferation of coral diseases to elevated seawater temperature, suggesting that climate change will lead to even greater incidences of disease in Brazil in the future. If the area’s corals continue to die off at the current rate, Brazil’s reefs will suffer a massive coral cover decline in the next 50 years.
Recent news reports from Texas to Jamaica to the Bahamas have documented the rapid spread of the lionfish—an invasive marine species. Lionfish have quickly become established across the waters of the southeastern U.S. and the Caribbean. New sightings abound—earlier this month lionfish reached the Flower Garden Banks National Marine Sanctuary off the coasts of Texas and Louisiana. Because of their role in upsetting the ecological balance of coral reef ecosystems, the rapid growth in the populations of these fish poses a grave threat to the region’s coral reefs. Consequently, the region’s fishing and tourism industries, which depend on coral reefs, may also be at risk. Governments across the region are trying to respond to the lionfish invasion by developing new campaigns and cooperation strategies that could pose important lessons for how to deal with invasive marine species in the future.