Coral Triangle Maps of the Month

The Coral Triangle Maps of the Month is a monthly email running from August 2012 to June 2013 that showcases various maps that highlight the diversity and uniqueness of the Coral Triangle region. The maps also show some of the pressing issues that are threatening this very important resource considered the epicenter of the world's marine biodiversity. The maps are generated by the Coral Triangle Atlas team at WorldFish.


   Click map to enlarge


Map 14: Seagrass Species Richness in the Coral Triangle

In Papua New Guinea (above) and throughout the Coral Triangle, seagrass beds are closely linked to coral reef species, and are a nursery for many reef fish. Here, clown fish live in a sea anemone located in a seagrass bed

Seagrasses are underwater plants that pollinate and flower beneath the world's oceans, and are present on the coasts of every continent except Antarctica.  Seagrass often occurs in vast meadows from the intertidal to 50 meters depth and provides nursery habitat, shelter, and food for a variety of commercial, recreational, and ecologically important species.  Additionally, seagrasses filter estuarine and coastal waters of nutrients, contaminants, and sediments.  In the tropics, seagrasses are linked to coral reefs and mangrove forests.  Existing at the interface of the land margin and the world's oceans, seagrasses are threatened by numerous anthropogenic impacts including global climate change.

The Coral Triangle is considered the center of biodiversity for seagrasses and is the region where, in evolutionary history, seagrasses returned to the oceans from their terrestrial origins 100 - 65 million years ago.  There are 15 species of seagrass found in the Coral Triangle, out of 72 species worldwide.  These include the largest tropical species which, unusually for seagrass, pollinates at the water's surface, and the smallest species, with tiny oval leaves that project slightly above the bottom and are often excavated by dugong for food.  There is also a small seagrass commonly found growing within mangrove prop root habitat that is considered Vulnerable by the IUCN Red List due to the widespread destruction of mangroves in the area of the Coral Triangle.   

Although seagrass meadows cover a relatively small portion of the ocean floor or around 1%, seagrasses constitute an important global carbon sink, accounting for about 15 per cent of total carbon storage in the oceans. Seagrass habitat is a nursery for young marine creatures including many reef fish, creating zones of very high biodiversity. The seagrass root mat adds stability to the coastal zone, and seagrass leaves lessen the impact of wave energy on the shoreline.  As dead seagrass breaks down, it becomes part of the marine food web, supporting fish, snails, shrimp, and beche de mer.  Throughout the Indo-Pacific, people harvest many seafood species from seagrass meadows, providing a major source of protein in the diet.              

Seagrass is the primary food of both dugongs and sea turtles.  Dugongs are endangered as are all sea turtle species. Seagrasses themselves in the Coral Triangle range from healthy to heavily impacted.  In remote areas with little human influence, seagrasses thrive but along developed coastlines and in areas of aquaculture, seagrasses are declining and many hundreds of hectares are lost each year.  Seagrasses are one of the fastest declining marine habitats worldwide and the resource must be conserved and protected within the Coral Triangle to maintain ocean health and productivity.  - Fred Short,

Do you need more maps on the Coral Triangle?  


Follow this link to download a high-resolution version of this map from the CT Atlas website
To see more maps, view the CT Atlas Map Gallery online
To generate your own map, check out the CT Atlas interactive map  

Follow these links to see other maps in this series:

Map 01: The Eleven Ecoregions of the Coral Triangle

Map 02: Marine Protected Areas in the Coral Triangle

Map 03: Marine Protected Areas in Indonesia

Map 04: Marine Protected Areas in Malaysia

Map 05: Marine Protected Areas in Papua New Guinea

Map 06: Marine Protected Areas in the Philippines

Map 07: Marine Protected Areas in the Solomon Islands

Map 08: Marine Protected Areas in Timor-Leste

Map 09: Reefs at Risk in the Coral Triangle

Map 10: Concentration of Coral Species in the Coral Triangle

Map 11: Threatened Fish Species in the Coral Triangle

Map 12: Reef Fish Biodiversity in the Coral Triangle
Map 13: Mangrove Species Richness in the Coral Triangle



Click to Join Our Mailing List


About the Coral Triangle Atlas

The Coral Triangle Atlas is an online Geographical Information System (GIS) database providing scientists, governments and NGOs with a view of spatial data at the regional scale. This project will improve the efficiency of conservation planning in the region by giving researchers and managers access to biophysical and socioeconomic information in spatially explicit while encouraging them to share their data to complete the gaps, therefore reducing duplicate data collection efforts and providing the most complete and most current data available.

By contributing data to the CT Atlas, NGO partners, governments and managers are helping to strengthen the effectiveness of conservation activities in the Coral Triangle through improved information flow and access to the region's best datasets.

The CT Atlas is supported by USAID's US CTI Support Program through the Coral Triangle Support Partnership. It also works to inform the Coral Triangle Initiative on Coral Reefs, Fisheries ad Food Security - a multilateral partnership formed in 2007 by the six Coral Triangle countries to address the urgent threats facing the Coral Triangle.

For more information about the CT Atlas and to contribute data, contact: Annick Cros at or ReefBase at You can also participate in discussions or submit questions to the CT Atlas forum