Coral reefs facing threat from pollution, dredging and blast fishing

A swelling population, land use change, unscientific waste disposal, mining of corals, coastal erosion, and unregulated construction are exerting pressure on the Lakshadweep islands, one of the most sensitive and fragile coastal environments in the country.

A study on the state of the environment of the island group, conducted by the Kerala State Council for Science, Technology and Environment (KSCSTE), has found that the coral reefs face the greatest threat from pollution, dredging of navigational channels, coral mining, and destructive practices like blast fishing. The final report of the study warns that sea-level rise triggered by global warming could also be indirectly impacting on the archipelago comprising reefs, lagoons, beaches, and sand dunes.

The project team coordinated by Kamalakshan Kokkal, Joint Director, KSCSTE, involved 28 scientists from various research institutes. Dr. Kokkal told The Hindu that the survey funded by the Ministry of Environment and Forests, had utilised data up to the year 2011 to assess the state of the environment.

The study notes that the population density in the inhabited islands is over 2,000 persons a square km, much above the national average of 324. Amini has the highest density of 2,839 persons a sq km. Most of the 10 inhabited islands are urbanised or showing signs of urbanisation. The increase in population was pushing settlements further shoreward, forcing changes in land-use pattern along the coast. The scientists have called for an awareness campaign on population control.

The limited ground water resources in the islands are already strained by over exploitation. Salinity intrusion caused by rising sea level could aggravate the situation, the study warns. Pointing out that Lakshadweep was located along the main route for oil tankers plying between the Middle East and Southeast Asia, it notes that oil spillage and discharge of waste oil and untreated waste into the sea could pose a potential threat to the rich marine biodiversity of the region.

The report has called for strict enforcement of the Coastal Regulation Zone norms to protect the islands. It recommends the creation of a biosphere area and the establishment of marine parks for sustainable management of biodiversity. The project team stresses the need to adopt eco-friendly coastal protection measures such as beach nourishment, submerged breakwaters and artificial reefs. It moots the installation of desalination plants, sewage treatment facilities and solar power units on all islands. The report also proposes a coral monitoring programme and strict curbs on capture of ornamental fish.

The presence of 103 types of corals, 469 species of molluscs, 138 species of plants, 114 varieties of sea weeds, 90 species of sponges, and six types of sea grasses were recorded from the islands. Over 695 species of fish, including 300 varieties of ornamental fish, were documented.

The rapid growth of predators such as the crown-of-thorns starfish (Acanthaster planci) has been identified as a major threat to corals. Cyclones, storms, and tidal waves were also taking a heavy toll on the corals and associated fauna, the report says.

The project team highlights the need to create a comprehensive database on biodiversity of the islands and come up with a climate change adaptation and management strategy.