CARIBBEAN CORAL REEFS

The Caribbean coral reef system is the first marine ecosystem in the world to collapse. Other coral reefs and ecosystems across the world will also collapse unless we act now.

"a complete collapse of coral reefs in the Caribbean, including the Belizean Barrier reef, is the first record of the collapse of an entire regional marine ecosystem" IUCN, 2012.

Artificial coral reefs provide huge economic returns for minimal investment, provide employment and skill training for local communities, and can conserve endangered corals see Artificial coral reefs 

The Belizean Barrier Reef is the second largest barrier coral reef in the world. Its value for tourism and the challenge of its conservation places Belize in a position to become a leader in coral reef protection and management.

  Fish on Ambergris Key  Turtle on Ambergris Key. Image Peter Janzen.
 Tarpon are still very common on Ambergris Key     Diver on Ambergis Key.  

Above: Ambergris Key, Belize, is a very popular tourist, fishing, and diving location. Images by Peter Janzen.

  • Besides their exceptional beauty and high biodiversity, coral reefs are valuable for many reasons.  
  • Coral reefs boost tourism dollars to local communities and support fish stocks. 
  • Coral reefs also build the keys, and protect coastal development from waves, tsunami's, and hurricane surges. 
  • Coral reefs provide nesting sites for turtles and birds

Below: The keys low height above sea level, closeness to the reef, and often sandy soil make them particularly threatened by hurricanes. Images by Peter Janzen.

 Tourist pier Ambergris Key. Image Pater Jenzen. Development on Ambergris Key. Image Peter Janzen. 

Although the major tourist resorts retain their traditional Caribbean lifestyle they also support an increasing number of western style homes and businesses. This puts stress on the keys fragile ecosystem that besides reef also includes seagrass and mangroves.

Our collaborator ACES works to protect the American crocodile on Ambergris Cay and offers visitors the opportunity to join with them in their release or rescue program.

   
 Bird

 

The cays behind the reef provide nesting habitat to a wide variety of sea and land birds. 

These birds make important contributions to the health of the reef by concentrating nutrients in mangrove forests. Mangroves prevent erosion, provide habitat for juvenile fish and many other species, and improve water quality through increasing nutrients and cleaning silt from water.

On Ambergris Cay dozens of frigate birds come around the jetty when fish are cleaned. They have wingspan's of 7 foot (2.3 meters) and make spectacular dives close to the pier to the delight of tourists. The cleaning of fish also attracts very large stingrays that glide over the seagrass.

 

Frigate birds on Ambergris Key. Image Peter Jenzen.

EXTENSIVE LOSS OF CORAL

There has been an extensive loss of coral in the Caribbean over the last 40 years. For example, the coral cover of the Belizean barrier reef is only one tenth of its original cover, and less than 5-7% compared with 50-70% in the 1970's. Similar loss of coral to that on the Belizean barrier reef is apparent throughout the Caribbean.

http://planetsave.com/2012/09/08/caribbean-coral-reefs-are-mostly-dead-iucn-says/?goback=.gde_1087937_member_161095141

 

Dead coral web Coral regrowth 
Dead and broken coral on the Belizean barrier reef. Image Peter Janzen. Coral regrowth on Belizean barrier reef. Image Peter Janzen.


The loss of coral is also occurring in the Indian Ocean and with the Australian Great Barrier Reef. In the Indian Ocean some 500 to 1000 year old corals have died due to warmer water and increasing ocean acidification.

This crisis has resulted in the International Union for Conservation of Nature (IUCN) declaring "a complete collapse of coral reefs in the Caribbean - the first record of the collapse of a regional marine ecosystem".

    Coral reef landscape. Image Peter Janzen.
The coral reefs of Belize and the Caribbean are central to tourism, incuding diving and fishing. We should identify the causes of their loss and then prevent them. Images Peter Janzen.

 CAUSES OF CORAL LOSS

Sea Urchins in the 1970's - Beginning the decline in coral cover was massive mortality among sea urchins in the 1970s, possibly caused by human introduced disease. Sea urchins eat algae and other plants on the bare parts of the reef. Less sea urchins meant a lot more algae and other plants, and these stop new coral covering the bare patches.

Hurricane damage 1998- 2000 - The reefs were still fairly intact until 1995-1997 where the older fishermen describe the abundant coral. Hurricane Mitch in October 1998, and two years later tropical storm Chantal and hurricane Keith damaged the reef so much that it has never recovered. The damage was direct physical destruction combined with very high silt loads. Now where there was clean sand the bottom is silty and sometimes putrid, through the hurricanes and subsequent river siltation and local development.

Over fishing - The loss of grazer species such as parrotfish or surgeon fish allow algae to out compete coral for anchorage on the reef.

Warmer water - Predicted ocean temperature increases from global warming cause coral to bleach and die and may massive loss of coral reefs over the next few decades. Coral bleaching occurs when plants (algae) that live inside coral leave because of warm water. The corals go white and eventually die. Coastal fishing villages like Sarteneja will be particularly vulnerable to climate warming because of the loss of marine resources and rising ocean levels.

Acidifying oceanic waters - The atmospheric increase in carbon dioxide (CO2) levels has resulted in increased acidity of oceanic waters.

Pollution - Corals are very sensitive to water pollution from chemicals or silt. To protect the Australian Great Barrier Reef many harmful chemicals used for sugar or banana production have been restricted or banned. Tourist facilities need to make sure that no pollutants enter the ocean.

Warmer water and other factors combined - Temperature-induced mass coral bleaching started when atmospheric CO2 levels exceeded 320 ppm. When CO2 levels reached 340 ppm, sporadic but highly destructive mass bleaching occurred in most reefs world-wide. At today’s level of 387 ppm, allowing a lag-time of 10 years for sea temperatures to respond, most reefs world-wide are committed to an irreversible decline.

Mass bleaching will in future become annual - If CO2 levels reach 450 ppm (due to occur by 2030–2040 at the current rates), reefs will be in rapid and terminal decline world-wide from multiple factors including mass bleaching, ocean acidification, and other environmental impacts. If CO2 levels reach 600 ppm reefs will be eroding geological structures.

Ocean level rises - Even small rises in ocean levels can effect coastal communities. Higher ocean levels combined with loss of coral will mean greater wave action, tidal and storm flows, and flooding during high tides.

The future - The major threat to reefs are increasing atmospheric CO2 levels that promote global warming and ocean acidification. The negative effects of both can be slowed by reduction in the use of fossil fuels, deforestation, and burning. see Forest carbon storage and Soot and global warming

  • Marine protected areas can reduce the pressure of over fishing. 
  • Grazing fish make bare areas for the coral to grow, and the taking of these fish is banned in Belize and many other countries. 
  • As marine environments change, and fishing catches decrease, local communities can develop sustainable lifestyles through developing alternative economic activities. These include activities such as Agriculture, Tourism, Development, Niche Products, and Artificial Coral Reefs.