Coral reefs, mangroves forests, and seagrass beds support an incredible diversity and abundance of ocean life including fishes, invertebrates, mammals, and seabirds. These in turn support lucrative fishing and tourism industries for the countries whose waters contain them. These three types of marine habitats exist in very specific environmental conditions in shallow, warm, tropical and subtropical oceans. They are crucial to sustaining coastal marine ecosystems, yet they are susceptible to human-caused disturbances such as physical damage, pollutants, and climate change.
Moreover, the value of these ecosystems extends beyond fisheries to supporting the longevity of coastal communities. Coral reefs, mangroves, and seagrasses are natural buffers for waves that would otherwise erode the shoreline. They protect coasts from extreme events like storm surges and tidal waves. In addition, mangroves and seagrasses provide extra protection by binding sediment and stabilizing the shoreline. All three ecosystems serve as filters for suspended particles and pollutants, maintaining good water quality necessary for the other organisms living there.
Right: Coastal pollution surrounding a port in neighboring Djibouti. Photo credit: Jerome Michelet.
Coral reefs are built by colonies of small invertebrate polyps (tentacled animals related to sea anemones and jellyfish) that secrete a limestone skeleton giving reefs their structures. It takes from decades to centuries to build a coral reef, and they are fragile and difficult to repair once damaged. Unfortunately, coral reefs face myriad threats from humans. One major threat is overfishing, which disrupts the balance of the ecosystem, leading to decreased biodiversity and environmental health. Destructive fishing practices such as bottom trawling or dynamite fishing damage or destroy the physical reef structure and degrade the integrity of habitat. Corals are also sensitive to changes in water quality. Pollution and sedimentation from activities on land affect the coral polyps and the animals living on the reef. Additionally, acidification of the ocean as a result of climate change can slow the growth of corals, making it more difficult for the reef to recover from damage.
Mangroves are salt-tolerant trees or shrubs that grow partially submerged in sheltered coastal areas. Mangrove forests create a canopy used by birds and terrestrial animals, similar to a conventional forest. Their uniqueness and value for the coastal ecosystem, however, comes from their extensive root systems below the water. Mangrove roots create habitat for marine animals, especially juvenile fishes and invertebrates like crabs that can avoid large predators among the complicated root systems. Though their benefits are clear, they are susceptible to many of the same threats from humans as coral reefs, and therefore should be similarly protected.
Seagrasses are flowering plants that grow entirely submerged in warm, shallow ocean water. They can form vast meadows that provide refuge and foraging areas for many commercially important fishes. They also cycle nutrients that sustain life in the shallow seas and other parts of the ocean. Seagrasses depend on a delicate water chemical balance and sunlight penetration through the water, and they are therefore at risk from human activities that affect water chemistry or clarity. Mitigation measures such as sewage and water treatment and runoff prevention are especially important for preserving seagrasses.
Because these ecosystems are so sensitive, coastal development and the industries that support it, especially in large population centers, will need to proceed with these resources in mind to avoid inundating the area with pollutants. Damaging these ecosystems would undermine coastal livelihoods and potentially cause conflicts between fishing communities and developers, local, regional, and federal governments, and citizens in other coastal industries.
The Somali marine environment supports a few areas of coral reefs, mangroves, and seagrasses that hold opportunities for coastal communities, as long as they are treated with care. The fisheries these ecosystems support are an important component of the local economy. Maintaining and protecting these ecosystems could have major economic benefits for Somalis. If managed well and fished sustainably, Somali marine habitats could support the local fishing sector well into the future.
Data Attribution and License Information
Data visualization by Paige Roberts. Reproduced with style modification from World Resources Institute, Reefs at Risk Revisited, 2011. http://www.wri.org/reefs.
This work is licensed under a Creative Commons Attribution 4.0 International License (CC-BY-4.0) by World Resources Institute. For more information and for data downloads see www.wri.org/reefs.
Mangrove Forests and Seagrass Beds
Giri C, Ochieng E, Tieszen LL, Zhu Z, Singh A, Loveland T, Masek J, Duke N (2011). Status and distribution of mangrove forests of the world using earth observation satellite data (version 1.3, updated by UNEP-WCMC). Global Ecology and Biogeography 20: 154-159. doi: 10.1111/j.1466-8238.2010.00584.x . Data URL: http://data.unep-wcmc.org/datasets/4
UNEP-WCMC, Short FT (2016). Global distribution of seagrasses (version 4.0). Fourth update to the data layer used in Green and Short (2003). Cambridge (UK): UNEP World Conservation Monitoring Centre. URL: http://data.unep-wcmc.org/datasets/7
For licensing information see UNEP-WCMC General Data License https://www.unep-wcmc.org/policies/general-data-license-excluding-wdpa#data_policy.
Burke, Laura, Kathleen Reytar, Mark Spalding, and Allison Perry. Reefs at Risk Revisite. Washington, D.C.: World Resources Institute, 2011. http://www.wri.org/sites/default/files/pdf/reefs_at_risk_revisited.pdf
United Nations Environment. “Seagrass.” Biodiversity A-Z. Accessed August 8, 2017. http://biodiversitya-z.org/content/seagrass
United Nations Environment. “Mangrove.” Biodiversity A-Z. Accessed August 8, 2017. http://biodiversitya-z.org/content/mangrove--2