Belize Barrier Reef
By Sue Wells, UNDP/GEF Coastal Zone Management Project, Belize
"The Most Remarkable Reef in the West Indies"
So Charles Darwin referred to the Belize Barrier Reef in 1842, in his
study of the origin and evolution of coral reefs. Since then
it has become renowned as the largest barrier reef in the Western Hemisphere. Nearly 260km long, it runs from the northern
border of the country, where it is only about 1km offshore, south to the Sapodilla Cayes which lie some 40km offshore.
Belize also has one of the most diverse reef ecosystems in the world,
with all the main types of reef represented: fringing reefs
along the mainland coast; the Barrier Reef itself which grows along the edge of the continental shelf, separated from the
mainland by the lagoon; and three offshore atolls (Lighthouse Reef, Turneffe Atoll and Glovers Reef). The presence of atolls is
unusual. Most atolls are found in the Pacific, where they form on the top of submerged volcanoes. Very few occur in the
Caribbean, and they differ in structure, the three in Belize for example lying on non-volcanic submarine ridges.
The Diversity of Coral Reefs
Of all wetlands, coral reefs are the most diverse, being home to more
species than any other marine ecosystem. Only tropical
rain forests rank higher on the biodiversity scale. This huge diversity is a result of careful partitioning of the reef by all its
inhabitants - some use the reef at different times of day (many reef species are nocturnal), others share it by eating different
food. Although reef diversity is much lower in the Caribbean than in the Indo-Pacific (a result of the geological history of the
region), over 1,000 species may nevertheless occur on a single reef. Belize has a particularly high species diversity for the
region, with about 65 coral species and over 300 fish species, compared with just over 70 coral species and about 520 fish
species in the Caribbean as a whole.
The colourful Queen Angel, one of the 300 fish species recorded at the reef. (Photo: James Beveridge)
Fish and invertebrates (notably molluscs, crustaceans, echinoderms and corals) predominate, but algae are also abundant. More species of fish are found on reefs than anywhere else in the sea, ranging from large sharks to tiny gobies. Most species on a reef are in fact never seen by divers and snorkellers as they are tiny, cryptic invertebrates that live in cracks and crevices and can be equated with the insects of the tropical rain forest. It is also likely that about 90% of all reef species, particularly the small invertebrates, are still undiscovered: SCUBA diving equipment was invented less than 50 years ago, and most reefs have only relatively recently become accessible to researchers. New species are being described all the time. For example, an entirely new biodiversity 'hotspot' has been discovered on the Belize Barrier Reef in the last two years in the semi-enclosed lagoons of the Pelican Cayes, a group of mangrove covered cayes. These have startlingly rich, colourful and unusual communities of sponges, corals, and other reef species encrusting the mangrove roots and lagoon sides; in one lagoon, over 40 species of seaquirts (a small, primitive, chordate) have been found.
Reefs also attract large animals such as turtles including the threatened
Hawksbill Turtle, Eretmochelys imbricata (IUCN Red
List, 1994), and seabirds such as the Red-footed Booby Sula sula and the Magnificent Frigatebird Fregata magnificens,
which come to feed on the smaller inhabitants or which depend on the closely associated seagrass beds and mangrove habitats.
Although all three wetland types can and do occur independently of each other, in many areas they form an integrated
ecological system. Mangroves thrive in calm, turbid, nutrient rich environments, protect reefs from terrestrial sediments and
provide shelter among their roots for many juvenile reef species. The seagrass beds stabilize sediments and also provide an
important food source for many reef animals. Coral reefs require clear nutrient poor waters, and play an important role in
protecting mangroves and seagrasses from erosion during storms and strong wave action. The Belize reef ecosystem illustrates
this well, the reef protecting and being linked with extensive areas of coastal wetlands, lagoons, seagrass beds and
mangrove-covered cayes and coastal areas.
Utilization of the Reef
In Belize, the coastal waters were used extensively for fishing by the
Mayans between 300 B.C. and 900 A.D. Since early this
century, the economic role of the reef has increased steadily with the growth of the coastal population. Initially, its importance
lay in the fishing industry, with a wide variety of species being harvested ranging from turtles, sharks and finfish, to sponges and
seaweeds. Today, lobster and conch are the principal fisheries products, and contribute most of the total value of exported
seafood, estimated at over US$10 million in 1995. There is also a domestic fishery for shallow reef fish and a commercial
fishery for groupers Epinephelus spp. and snappers Lutjanus spp. However, the main use of the Belize Barrier Reef is now
tourism, which is the country's largest source of foreign exchange generating an estimated US$75 million in 1994; hundreds of
divers visit the reef each year to experience its delights.
Threats to the Reef System
Belize may be one of the last countries in the world to have extensive
areas of almost pristine reef but it is also subject to the
many threats that are of global concern and which have already seriously degraded an estimated 10% of the earth's coral reefs
and currently threaten a much greater percentage. Greatest damage comes from sedimentation, agrochemical run-off, coastal
development, tourism and overfishing. Until recently, the main impacts on the Belize Barrier Reef were from natural events such
as hurricanes. However, pressures are mounting from a whole range of impacts including escalating residential and hotel
development on numerous cayes, the citrus and banana industries which are causing increasing fertilizer run-off, growing
numbers of shipping and recreational vessels in the reef-strewn shallow waters, and a steady increase in divers and snorkellers -
Hol Chan Marine Reserve alone now receives over 30,000 visitors a year.
Status of Belize Coral Reef
Coral reefs have not yet been used among the primary criteria for listing
wetland sites under the Ramsar Convention, although
the definition of a wetland allows for their inclusion. Of the 11 Contracting Parties to Ramsar in the Neotropics that have coral
reefs, only 3 have listed sites that include these habitats (the Grand Cul de Sac Marin in Guadeloupe, Klein Bonaire Island and
adjacent waters in the Netherlands Antilles, and North, Middle and East Caicos Islands in the Turks and Caicos) and in all
cases the main interest in these wetlands has been other habitats and waterfowl. Belize is finalising the process for joining
Ramsar and, in the first instance, will be nominating an inland wetland site. However, several parts of the Belize Barrier Reef
would qualify for nomination.
A system of marine and coastal protected areas is being set up as part
of the Coastal Zone Management Plan that is being
prepared for the country. So far there are three protected areas that include reefs: Half Moon Caye Natural Monument on
Lighthouse Reef, Hol Chan Marine Reserve on the Barrier Reef, and Glovers Reef Marine Reserve. A number of other areas
are likely to be designated as marine reserves or national parks soon, and many of these will be large areas incorporating a
range of wetland habitats including the central section of the Barrier Reef, extensive lagoon and saltmarsh areas as well as vast
expanses of estuaries, mangroves and fringing reefs.