Odisha’s coastal ecosystems under increasing threat
Over three billion people in the world depend on marine and coastal biodiversity for their livelihoods. Oceans contain nearly 2 lakh identified species, but actual numbers may lie in the millions. Oceans absorb about 30 per cent of carbon dioxide produced by humans, buffering the impacts of global warming. However approximately 40 per cent of the oceans are heavily affected by human activities, including acidification, pollution and loss of coastal habitats.
The United Nations has proclaimed June 8 as the World Oceans Day to raise awareness of the plight of the oceans and the marine ecosystems they contain. This year’s theme is “Together we have the power to protect the ocean”.
The oceans — their temperature, chemistry, and life — drive global systems that make the Earth habitable for humankind. Our rainwater, drinking water, weather, climate, coastlines, much of our food, and even the oxygen in the air we breathe, are all ultimately provided and regulated by the sea. Oceans and seas have been vital conduits for trade and transportation.
However, oceans and coastal regions are coming under rising environmental pressures. The oceans have become 26 per cent more acidic since the start of the Industrial Revolution and continue to acidify at an unprecedented rate, threatening marine ecosystems, aquaculture and the societies that rely on them. As ocean acidity increases, its capacity to absorb carbo dioxide from the atmosphere decreases. This decreases the ocean's role in moderating climate change.
Our continued burning of fossil fuels is increasing the levels of carbon dioxide in the atmosphere. Most of the carbon dioxide released into the atmosphere ultimately ends up in oceans. The increasing amount of carbon dioxide in oceans is causing ocean acidification. For millions of years, oceans have maintained a relatively stable acidity level. It's within this steady environment that the rich and varied web of life in seas has arisen and flourished. But research shows that this ancient balance is being undone by a rapid drop in surface pH that could have devastating global consequences.
Ocean acidification may adversely impact some plankton species, and their loss would ripple through food webs to impact larger animals like fish. Corals are also very susceptible to the impacts of ocean acidification. Ocean acidification will affect ocean ecosystems and therefore food supplies, lead to the death of coral reefs and thus expose coasts to greater storm surge and wave action. Ocean acidification has the potential to cause widespread changes in marine ecosystems which may eventually disrupt the ocean goods and services we depend on.
Biologists are now coming to realise that the rising acid levels in the ocean can affect many other forms of sea life as well. If nothing is done to help curb ocean acidification, its negative impacts may be felt on global economy. Besides, many ocean pollutants are released into the environment from coastlines. Nitrogen-rich fertilisers applied by farmers inland, for example, end up in local streams, rivers and oceans.
Researchers are just beginning to study the effects of ocean acidification on marine ecosystems. But all signs indicate that unless humans are able to control and eventually eliminate fossil fuel emissions, ocean organisms will find themselves under increasing pressure to adapt to their habitats’ changing chemistry or perish.
The Global Ocean Observing System (GOOS) monitoring initiatives has improved the capability to assess oceanographic conditions, making it possible to detect changes on high temporal and spatial resolution and assess the effectiveness of policies adopted. To coordinate international efforts to document the status and progress of ocean acidification in open-ocean and coastal environments and to understand its drivers and impacts on marine ecosystems, it will be necessary to develop a coordinated multidisciplinary multinational approach for observations.
India has a coastline of 7,500 km and 2,000 km wide exclusive economic zone. The coastline supports almost 30 per cent of its human population. The Bay of Bengal and the Arabian Sea are rich fishing grounds. Various types of pollution cause degradation of the natural quality of the coastal environments. The causes of coastal pollution are population growth, urbanisation and industrialisation. The polluting sources mainly are domestic waste, industrial effluents and agricultural runoff.
Successful management of the seacoast depends on scientific exploration and exploitation of the living and nonliving resources in coastal waters. To conserve resources by controlling their depletion and regulate development activities, the Government of India has enacted the Environmental (Protection) Act 1986. The Coastal Regulation Zone (CRZ) Notification 1991 was issued under Sections-3(i) and 3(ii) (v) of the Environment (Protection) Act. Under this notification, the coastal stretches from High Tide line to 500m towards land and from High Tide line to low Tide line towards sea are identified as Coastal Regulation Zone.
The Union Ministry of Environment and Forests has issued a draft notification, the Coastal Zone Management (CZM) Notification 2007, under the Environmental (Protection) Act 1986. The objective of the notification is protection and sustainable development of the coastal stretches and marine environment through sustainable coastal zone management practices based on sound, scientific principles taking into account the vulnerability of the coast to natural hazards, sustainable livelihood for local communities and conservation of the ecologically and culturally significant coastal resources.
Odisha has a coastline of 480 km. Uses of the coastline are generally considered under four categories: resource exploitation (including fisheries, forestry); infrastructure (including transportation, ports, harbours); tourism and recreation; and conservation and protection of biodiversity. The coastal ecosystems are now highly disturbed and very much threatened, encountering problems like pollution, siltation, erosion, flooding, storm surges, uncontrolled coastal developments and other activities due to ever-expanding human settlements.
The major issues are coastal pollution, encroachment of coastal lands and overexploitation of coastal resources. Coastal pollution is gradually emerging as an important issue in the State. Domestic wastes and industrial wastes, fertilisers and pesticide residues reach coastal and marine waters through rivers, creeks, bays, etc.
There is a need for assessment and periodic monitoring of coastal and marine environment including changes in land use (coastal zone), ambient air quality and water quality (coastal and marine waters). The Government of India has constituted the National Coastal Zone Management Authority, which has the responsibility for taking measures for protecting and improving the quality of the coastal environment and preventing, abating and controlling environmental pollution in coastal areas. At the State level, an Odisha Coastal Zone Management Authority has been constituted, the primary responsibility of which is to take adequate measures for protecting and improving the quality of the coastal environment. The Odisha State Pollution Control Board acts as the regulating authority for implementation of the Coastal Zone Notification.
Despite the huge challenges facing the world’s ocean, we can achieve a healthy ocean by our collective effort. Awareness is highly needed to protect the marine ecosystem.
(Dr Mayarani Praharaj woks in the Department of Architecture, College of Engineering and Technology, Bhubaneswar)