TYPES OF CORAL REEFS 1. Coral Atoll2. Fringing Reef3. Barrier Reef

CORAL ATOLLIsolated ring shaped reef rising out of deep

water.

FRINGING REEFA shallow water feature found close to and

parallel to the shore. Buchanan (1974) maybe 0.5 to 2.5 km in

width.

BARRIER REEFParallel to the coast but separated from it by

a lagoon ( a shallow body of water separated from the sea by a narrow strip of land).

THREATS TO CORAL REEFSLand –based threats Marine activities Worldwide threats

LAND BASED THREATSHuman activity on land in coastal regions has altered the near shore environment, threatening the reef.

Around islands such as Barbados, Jamaica, and Tobago reefs have been damaged by:

1. Too much fresh water : Coral polyps ( soft parts) need saline conditions. They do not grow where

rivers bring fresh water into the sea (Estuary). One such place in Jamaica is Agualta Vale- St.Mary.

Human activities increase the flow of fresh water after heavy rain, For example : when forest are

cleared or land is used for urban development .

2. Too much sediments: Corals need sunlight and clear water. They may be smothered when mud and

other sediment is washed into the sea, for example because of quarrying , construction of buildings or

soil erosion.

MARINE ACTIVITIES Coral reefs can also be threatened by large and small-

scale marine activities, such as:

Fishing: A well-managed fishing industry need not hurt the marine environment. However,

damage may be caused by anchors by over-fishing , or badly placed or discarded fish traps and

nets. A few fishers have used bleach or explosives, which cause serious and lasting damage to

the reef.

Oil spills: Oil and other chemicals can cause permanent damage. Small and mid-scale spills have

occurred many times in the caribbean. A large tanker may be 450 metres long and carries up to

500, 000 tonnes of oil, enough to pollute an entire coastline.

WORLDWIDE THREATS

Coral reefs are also threatened by worldwide changes, which cannot be

controlled within the

region. Higher sea temperatures caused by global warming may bring

‘bleaching’ of reefs.

Increased levels of carbon dioxide in sea water may slow coral growth , and

may also make

seawater slightly acidic.

PRESERVATION OF CORAL REEFS 1. Coastal management2. Pollution control

COASTAL MANAGEMENTPartly because of the threat of beach erosion, the Barbados government set

up a Coastal Zone

Management Unit in 1983. Its work includes:

Studying the action of waves , tides, and long shore drift, and how these

may affect the coastline;

Monitoring water quality, and the state of the offshore coral reefs;

Advising on shoreline protection and management.

POLLUTION CONTROLA wide range of measures is needed to help prevent further damage to the fringing reef and allow growing coral to recover. As an important part of its strategy, the government of

BarbadosBuilt a sewerage system on the south coast, which was completed in 2004. pipes were laidbeneath the road to collect waste water from houses and business places. A treatment plant removes all solid waste material for safe disposal on land, and a pipeline takes the liquid

waste 1,100 metres out to sea, where it is discharged in water which is 30-40 metres deep ,

beyond the fringing reef. From this point, the waste is rapidly dispersed by marine currents, and

washed out to sea.

The sewerage system reduced several problems:1. Fresh water is discharged away from the shore. Near shore areas remain saline,

allowing coral growth . 2. Sediment is not discharged into the sea.3. Most organic material and some chemicals are removed at the treatment plant. Other

chemicals are discharged in deep water, away from the growing coral.