In hot water — coastal and marine biodiversity

    Prakash Nelliyat
    Balakrishna Pisupati
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The ongoing, major event in Hyderabad, where 193 countries which are parties to the Convention of Biological Diversity (CBD), are in session — for the Eleventh Meeting of the Conference of Parties (COP 11) to the Convention — has come at an appropriate time when countries and people around the world are revisiting sustainable development frameworks and agendas. India is leading the global discussions on biodiversity and development between now and the next COP meeting, that is expected to be held in 2014.

All the recent international events on environment/biodiversity place a special emphasis on “coastal and marine” issues, primarily due to their significance to humanity and the threat to marine biodiversity. The ocean covers 71% of the surface area of the globe and constitutes over 90% of the habitable space. It contains the blue whale (the largest animal ever to have lived on earth) as well as microorganisms. Coastlines supporting fragile ecosystems include mangroves, coral reefs, seagrass and seaweeds.

Mangrove forests host a unique variety of fish and crabs, birds, monkeys, deer and even tigers. Coral reefs are known as the “rainforests of the sea.” Even though coral reefs occupy only 0.1% of the sea, one-third of all known marine species live on them. Seagrasses support different aquatic lives including marine turtles and juvenile prawns. About 1km{+2}of seagrasses absorbs approximately the same carbon-dioxide (CO{-2}) as 50km{+2}of tropical forests! Seaweeds are important marine living resources with a lot of commercial value. From time immemorial people have lived on the coasts and fishing. At present 41% of the world’s population lives within 100 km of the coast. Human dependence on the marine and coastal ecosystems is significant.

•Life in the sea produces a third of the oxygen that we breathe.

•The ocean absorbs approximately 30% of CO{-2}that has been emitted by human activities since the ‘Industrial Revolution’; this has helped in limiting the overall extent of global warming substantially.

•Fisheries directly employ almost 200 million people and provide over 15% of the dietary intake of animal protein.

•Marine bio-products are raw materials for manufacturing industries such as paints, fertilizers, skin lotions, toothpastes and medicines.

•The divergent chemical deposits in the marine environment are an asset, and might even yield new anti-cancer drugs.

•The shore provides for marine transportation, recreation, tourism and salt production.

•Mangroves can protect the coastal aquifers from seawater intrusion and safeguard the coastal communities from natural calamities like cyclones and tsunami.

•Coastal wetlands play an important role in water quality regulation by capturing and filtering sediments and organic waste transits from inland.

India has a coastline of about 7,500 km, of which about 5,400 km belongs to peninsular India and the remaining to the Andaman, Nicobar and Lakshadweep Islands. With less than 0.25% of the world’s coastline, India accommodates 63 million people, approximately 11% of the global population, living in low elevation coastal areas.


Even though humanity has benefited from the marine and coastal ecosystems, our activities (on land and ocean) have made critical impacts on their quality and renewability. Large-scale burning of fossil fuels is causing the ocean to become warmer and more acidic. The average sea surface temperature has increased by 0.4 degree Centigrade since the 1950s, which is a threat to the marine ecosystems, and ‘coral bleaching’ is a symptom. Since 1880, the sea level has risen by an average of 22 cm.

Dam construction and diversion of the flow of rivers have intercepted the transport of the much needed freshwater, sediments and nutrients to the coast, leading to disequilibrium in the ecosystems. Coastal urbanisation has squeezed sandy beaches and marsh lands. Toxic pollutants and non-biodegradable wastes such as plastic disposals adversely affect the reproduction, growth and behaviour of marine wildlife. Non-native species released from aquaria and ships’ ballast water discharge also assault the ecosystems and outcompete the native species. Even the noise generated by shipping and industrial activity can prevent species like whales from communicating with each other across miles of the ocean.

Over-hunting has reduced the stock of many species. The great auk and the sea mink have become extinct, and species such as the great whales have been hunted to a fraction of their original population. Today, more than four million fishing vessels, including industrial trawlers, are engaged in fishing to the tune of 140 million tonnes/year. It has been estimated that up to 13% of global fisheries have ‘collapsed.’ The commercial fisheries make vulnerable many deep sea species, retarding their reproduction and growth rates. Once the main fish stock has been depleted, it will take decades and potentially centuries to recover. Further 30-35% of critical marine habitats such as seagrasses, mangroves and coral reefs have been destroyed, primarily due to anthropogenic interventions.

Management strategies

When the population and developmental activities increase, the pressure on the coastal ecosystems also increases. It is important to utilise the services of the marine and coastal ecosystems for the overall development of the economy in a sustainable manner. The following proposals are made:

•For sustainable extraction of coastal resources (which are renewable), adequate knowledge of the bio-physiological functions of the ecosystems and their regeneration capacity at the regional level is required.

•Coastal and marine ecosystem/products are ‘public goods’ with an ‘open access’ character. Hence, they may experience ‘free-rider’ problems as well as ‘tragedy.’ However, biodiversity is an asset and the ‘right’ of future generations too. In this regard, strict enforcement of the law and ‘Coastal Zone Management’ policies are required.

•There is great scope for promoting and recovering coastal and marine biodiversity through the establishment of “Marine Protected Areas/Reserves.” At present, only a small area has been set aside as a reserve in marine and coastal waters (1%) compared to land (13%). However, the CBD has targeted to increase it to 10% by 2020.

• ‘Economic Instruments’ also need to be placed in coastal management. Pollution tax, user charges, fees, etc., may act as disincentives to resource degradation and depletion. Besides, incentive mechanisms such as payment for preserving ecosystems should be introduced.

•Land-based activities, which have an adverse impact on coastal and marine ecosystems, should be controlled immediately.

•Coastal biodiversity conservation must be a participatory process, with the support of various stakeholders including the general public.

(Dr. Prakash Nelliyat (Economist) and Dr. Balakrishna Pisupati (Chairman) belong to the National Biodiversity Authority, Chennai. email: uk; The views expressed in this article are personal and do not reflect those of the NBA)




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