Reefs at Risk in the Caribbean

Many people in coastal communities throughout Latin America and the Caribbean depend on the natural resources provided by reefs for their livelihoods. Ensuring proper management of the reefs is vital for the economic and environmental health of the region, but there is a lack of quality information about the relationship between human activities and coral reef condition across the region. The Reefs at Risk in the Caribbean project was a response to this information need. The primary goal of the project was to raise awareness and improve management of coral reefs across the region through improving the knowledge base on the status of and threats to coral reefs. In collaboration with partner institutions across the region, we implemented an analysis to link human activities with reef condition. A major component of the project involved modeling (estimating) threat to coral reefs from human activities.

Key findings from this report include:

• Nearly two-thirds of coral reefs in the Caribbean are threatened by human activities. Integrating threat levels from all sources considered in this analysis (coastal development, watershed-based sediment and pollution, marine based threats, and overfishing), the Reefs at Risk Threat Index identified about one-tenth of Caribbean coral reefs at very high levels of threat, one-third at high threat, one fifth at medium threat, and one-third at low threat.
• An estimated one-third of Caribbean coral reefs are threatened by coastal development. This includes sewage discharge, urban runoff, construction, and tourist development.
• Sediment and pollution from inland sources threaten about one-third of Caribbean coral reefs. Analysis of more than 3,000 watersheds across the region identified 20 percent of coral reefs at high threat and about 15 percent at medium threat from damage caused by increased sediment and pollution from agricultural lands and other land modification.
• Marine-based threats to coral reefs are widespread across the Caribbean. Our indicator of marine-based damage and pollution identified about 15 percent of Caribbean reefs as threatened by discharge of wastewater from cruise ships, tankers and yachts, leaks or spills from oil infrastructure, and damage from ship groundings and anchors.
• Overfishing threatens over 60 percent of Caribbean coral reefs. Fishing above sustainable levels affects coral reefs by altering the ecological balance of the reef. The removal of herbivorous fish, which consume algae, facilitates algal overgrowth of corals. Declines in coral cover and increases in algal cover have been observed across the region. This analysis identified about one-third of Caribbean reefs at high threat from overfishing pressure and about 30 percent at medium threat.
• Diseases and rising sea temperatures threaten to damage coral reefs across the Caribbean region. Diseases have caused profound changes in Caribbean coral reefs in the past 30 years, with very few areas unscathed by disease, even reefs far removed from human influence. In addition, coral bleaching episodes-the most direct evidence of stress from global climate change on Caribbean marine biodiversity-are on the rise.
• Ineffective management of protected areas further threatens Caribbean coral reefs. With the growth of tourism, fisheries, and other development in coral reef areas, marine protected areas (MPAs) are an important tool for safeguarding coral reefs. At present, over 285 MPAs have been declared across the Caribbean, but the level of protection afforded by MPAs varies considerably. The Reefs at Risk Project found only 6 percent of MPAs to be rated as effectively managed and 13 percent as having partially effective management.
• The coastal communities and national economies of the Caribbean region are poised to sustain substantial economic losses if current trends in coral reef degradation continue. Coral reefs provide valuable goods and services to support local and national economies, and degradation of coral reefs can lead to significant economic losses, particularly in the coastal areas of developing countries, through loss of fishing livelihoods, malnutrition due to lack of protein, loss of tourism revenues, and increased coastal erosion. Analyses carried out by the Reefs at Risk project indicate that Caribbean coral reefs provide goods and services with an annual net economic value in 2000 estimated at between US$3.1 billion and US$4.6 billion from fisheries, dive tourism, and shoreline protection services.

Reefs at Risk Caribbean on CD

The CD version of this report includes:

• Over 30 spatial data sets reflecting physical, environmental and socioeconomic variables for the Wider Caribbean;
• user-friendly map viewing software (ESRI ArcReader);
• Detailed country profiles for 35 Caribbean countries and territories
• Full technical notes on the threat modeling method;
• Technical notes on data sources and methods for the economic valuation;
• Complete set of maps in high and low resolution JPEG format.

To order a copy of the CD, contact reefsatrisk@wri.org.

Downloadable GIS Data Sets

Both download options provide estimates of threat to coral reefs for the four individual threats (coastal development, marine-based threats, overfishing, and sediment and pollution from upland sources), in addition to integrated threat – the Reefs at Risk threat index.

• Vector Data Sets (ZIP archive, 20.7 Mb) including data on coral reef locations, estimated threat to coral reefs from human activities, watersheds boundaries, and marine protected areas, all in ESRI ArcView shapefile format in Geographic projection.

  This option five polygon data sets reflecting estimated threats from human activities; five point data sets reflecting coral reef locations by these estimated threats; a polygon data set of watershed boundaries (with associated erosion estimates); a point data set reflecting river mouths and estimated relative sediment delivery; a polygon data set reflecting country boundaries; a line data set reflecting the coastline; and a point data set reflecting cruise ship ports of call. The zip file also includes an ArcView project file (rrcar_vec.apr) which requires ESRI’s ArcView software.

• GRID Data Sets (ZIP archive, 32.7 Mb) including data on coral reef locations, estimated threat to coral reefs from human activities, relative erosion rates across the landscape, and bathymetry, all in ESRI ArcView GRID format in Lambert Equal-Area Azimuthal projection.

  This option five GRID data sets reflecting estimated threat to coral reefs from human activities; five GRID data sets reflecting coral reef locations classified by estimated threat; a GRID data set reflecting estimated relative erosion rates across the landscape; and a GRID reflecting Bathymetry. All GRIDs are in Lambert Equal-Area Azimuthal projection.

  In addition, the zip file includes several vector shapefiles in Geographic projection – polygon watershed boundaries (with associated erosion estimates), polygon country boundaries, and a point data set reflecting river mouths and estimated relative sediment delivery. The zip file also includes an ArcView project file (rrcar_gr.apr) which requires ESRI’s ArcView software and Spatial Analyst 2.0 extension.

Online GIS

Reefs at Risk in the Caribbean data are available through two online GIS services:

• ReefBase. Reefs at Risk results from the global (1998), Southeast Asia (2002) and Caribbean (2004) analyses are available from ReefBase’s online GIS. This site displays Reefs at Risk threat analysis results along with a range of other reef-related data sets and satellite images.

• Caribbean Reefs at Risk. A web site focused on threats to Caribbean coral reefs has been developed through a partnership of the World Resources Institute (WRI), The University of the West Indies Caribbean Coastal Data Center (UWI-CDC), International Coral Reef Action Network (ICRAN), United Nations Environment Programme, Caribbean Environment Programme (UNEP-CEP), and the United States Geological Survey - National Biological Information Infrastructure (NBII). The site provides base data on the Caribbean basin, watersheds, and land-based threats to coral reefs, highlighting the results of the Reefs at Risk in the Caribbean analysis. The site provides mapping using online GIS, as well as data for download accompanied by metadata.