Coral reefs are one of the most diverse, complex, and beautiful marine ecosystems. The rich biological diversity of the coral reef ecosystem not only includes coral and the commercially important species associated with the reef but also thousands of other plant and animal species. They have survived millions of years of natural disturbances, but today they are facing bigger threats from human activities.
Coral reefs are important assets to local and national economies as they provide fisheries for food, materials for medicines, and income from tourism and recreation. They are recreational area for million of peoples. The potential yield of fish from coral reef ecosystem is about 10 per cent of the total commercial ocean fish landing.
Millions of people depend on reefs for livelihood. Reefs also create sheltered lagoons and protect coastlines and mangroves against wave damage. Mangroves in turn protect reefs from sedimentation. Mangroves and sea grasses also play an important role in coastal protection and provide spawning and nursery areas for reef and offshore fishes.
What are coral reefs? Corals are tiny, fragile organisms sometime called coral polyps. These colonial animals produce reef building calcium carbonate (limestone). Also they leave behind skeleton after they die.
The polyp uses calcium carbonate to build itself a hard, cup-shaped skeleton. This limestone skeleton protects the soft, delicate body of the polyp. Thousands of corals grouped together are referred to as coral colonies. Reefs are massive structures made of limestone that is deposited by corals. Over time, coral reefs, as the underwater habitats are called, grow and extend over wide areas of shallow seas.
Coral reef ecosystems in Pakistan waters are at risk as reefs are experiencing local as well as international pollution stress. Some important sources of stress include nutrient enrichment from sewage and agriculture, over fishing, and stress from high sedimentation caused by deforestation, agriculture, vessel traffic, shoreline developments, trampling by careless divers and coastal runoff.
These dangers have made environmental conditions unfavorable for coral growth. There are a few isolated patches of coral growth but the high sedimentation and very murky conditions limit their growth. Isolated patches of living coral colonies are also found between Hub River out fall and Churna Island. Live corals also have been recorded at several locations along the coast.
Pollution appears to be the main problems for reefs in Pakistan’s coastal waters. Moreover, local fishermen collect corals for selling. Destructive fishing methods contribute to the degradation of the environment of coral reefs.
The species may adapt to some gradual natural changes raise in temperature but they cannot survive threats by human activities. Which is why there is risk of extinction.
We should develop capacity to locate and identify possible reef areas. The development of area where coral are found should be carried keeping protection of this unique ecosystem in mind.