Coral reefs in Sri Lanka and elsewhere in the tropical world are under severe stress due to a variety of different factors. Many reefs have been lost as a result of man-made (anthropogenic) threats as well as natural causes. Rigorous efforts are needed to prevent any further damage to those fragile ecosystems.
Man-made pressures placed upon reefs.
· Over-fishing and destructive fishing practices
Over-fishing happens due to the increase in costal populations who depend on the fishery resources, as large numbers of people compete for limited resources. Certain technologically advanced fishing methods also contribute to over-fishing fisherman have easier and faster access to fishing grounds and hence marine resources are depleted faster than they can be replenished.
There are number of methods specifically designed for reef fisheries which are now illegal as they are harmful to the reef and result in over-fishing, which could lead to the ultimate collapse of the fisheries industry. Such methods are known as unsustainable (short-term methods that destroy important habits and resources).
WHAT ARE THE COMMONLY USED DESRUCTIVE FISHING METHODS?
· The use of small mesh sized nests
By the sue of this method, in additional to large fish, younger fish(juveniles) are also caught. This hampers the reproduction cycle of many species. The fish population takes longer to recover from the impacts of fishing, as the younger fish are removed before they have a chance to grow into adults and breed.
· The use of bottom set nests
This method is used to capture marine species dwelling within the reefs(e.g. lobsters, crabs). Corals are invariably damaged when the bottom set nets are hauled in with its catch. In addition, ornamental fish collectors use moxy nets to catch live fish, which also damages the reefs. A moxy net is similar to a cast net. A diver places the net over a patch of coral and chases the fish out of the coral by disturbing the coral under the net with a crow bar.
· Blast/Dynamite fishing
· Cyanide fishing
· Coastal Development and Pollution
· Tourism
Ø Construction and shoreline development related to tourism
Ø Boat and anchor damages
Ø Trampling by snorkelers, divers and bathers
· Aquarium Trade
· Demand for marine curios
· Coral Mining
