Spreading for 250 km along the entire length of the Belize, the country’s reef complex is the largest continuous reef system in the western Atlantic, extending from the northern end of Ambergis Cay to the Sapodilla Cays in the south. The barrier reef system encloses approximately 6,000 sq km of lagoon and includes over 1,000 cays.  The lagoon is 20 to 40 km wide and only a few meters deep in the north, deepening to 50 m towards the south. Throughout the reef lagoon there are numerous patch reefs. Reef growth along the Belize mainland is limited by fluctuation in salinity, high turbidity, and nutrients. Some fringing reefs occur in the very south between Placencia and Punta Ycacos, but have low species richness. 
Three atolls lie east of the barrier reef, separated by deep water: Turneffe Islands, Lighthouse Reef, and Glover’s Reef. Wave exposure plays a key role in shaping reef communities and development, both between atolls and within the atolls (on windward versus leeward reefs). In addition, a major influence on the barrier reef structure is the wave energy after attenuation by the atolls. 
The Reefs at Risk analysis rated 63 percent of Belize’s reefs as being threatened by human activities. Sediment and pollution from land-based sources were identified as a threat to about half of Belize’s reefs. Two major sources of nutrients entering Belize’s coastal waters are the run-off of fertilizers and the discharge of domestic sewage.  Land conversion and agricultural activities are estimated to reach reefs predominantly in the southern half of the country, which is impacted by the plumes of large Guatemalan and Honduran rivers. Large amounts of fertilizers are used on banana plantations located in the central and southern parts of Belize near rivers in areas of high rainfall. Citrus plantations in the coastal plains to the south also require the use of fertilizers. In the north, sugar cane is the predominant crop.
Overfishing was rated as a threat to over 35 percent of reefs. There is some evidence of overfishing by small-scale local fishermen and industrial fishing fleets, and many industrial fishers have been fishing outside the main fishing seasons.  Stocks of many commercially important local reef fish are faced with increasing fishing pressures.  Of the commercially important coral reef fish exploited, snapper and grouper comprise the bulk of the catch. Fish are captured by hook and line seasonally at traditional spawning banks scattered throughout the reef complex.
Coastal development was rated as a threat to 11 percent of reefs, especially around the larger cayes and tourist centers such as Amergis Caye and San Pedro Town, which are rapidly growing as a result of tourist-based economic activity.  Also, marine-based activities threaten an estimated 8 percent of reefs, particularly around the port facilities of Belize City and the cruise ship anchorage at Goff’s Caye.
Tourism, including the cruise-ship industry, is focused primarily on coastal centers and is rapidly becoming the major economic force.  Direct damage to corals has been reported from areas with intensive boat and diving activity, including anchor damage, boat groundings, and direct impacts from divers.  A high proportion of visitors to Belize make use of the marine resources. For example, in 2002, out of 186,097 visitors to the country, 46,404 visited the Hol Chan Marine Reserve. 
The frequency and intensity of natural disturbances having an impact on Belize’s reefs have increased in recent years, with several reefs affected by repeated and/or coinciding events.  Widespread bleaching took place for the first time off Belize in September 1995, when bleaching occurred throughout the Caribbean.  In the autumn of 1998, the reefs were again disturbed by a mass bleaching event, with some individual colonies bleaching more than 90 percent, over large geographic areas.  The same year Hurricane Mitch, a Category 5 storm, impacted much of the coast  when reefs experienced battering waves for several days.  Bleaching caused catastrophic coral loss in Belize’s lagoonal reefs,  while the hurricane caused widespread coral destruction in fore reefs and outer atoll reefs.  Then, Hurricane Keith followed in 2000 and Iris in 2001. These storms had different paths, intensities, and impacts  but they both reduced coral cover at a number of locations. Disease is also a problem. Beginning in the late 1980s, white-band disease nearly eliminated Acropora cervicornis from reefs in the central shelf lagoon of Belize. 
Considerable effort has been directed towards developing a system of marine protected areas.  The legal and institutional policy framework for managing coral reefs is in place, and MPA management is a mix of both government (either the fisheries department or the forest department) and NGOs.  The Belize Coastal Zone Management Authority and Institute is a model of integrated coastal management for the region, and the country’s system of 13 MPAs is well established, with almost all under active management.  Unfortunately, availability of long-term funding for enforcement and monitoring of the extensive MPA system is questionable. There is considerable reliance on international support. 
A. R. Harborne et al., “Belize” in Seas at the Millennium: An Environmental Evaluation. Vol 1 Regional Chapters: Europe, The Americas and West Africa. C.R.C. Sheppard, ed. (Oxford, UK: Elsevier Press, 2000), p. 598
 M. Spalding et al., World Atlas of Coral Reefs (Berkeley, California: University of California Press and UNEP World Conservation Monitoring Center, 2001), p. 117
 M.D. McField, “The Influence of Disturbances and Management on Coral Reef Community Structures in Belize.” Ph.D. thesis., University of South Florida, 2001, p. 9
 J. Gibson & J. Carter, “The reefs of Belize,” in Latin American Coral Reefs. J. Cort