Protecting India’s Coastal Bio-Shields

As an estimate, anthropogenic CO2 as well as atmospheric CO2, both have been increased with an annual growth of 2.053+-0.43 ppm per year. It can be stabilized by creating new carbon sinks. Coastal Ecosystems such as mangroves, coral reefs, sand dunes, sea-grass, salt marsh etc., are also very efficient carbon sinks and have a major role in sequestering atmospheric carbon dioxide. They help in offsetting:

  • Anthropogenic CO2 emission on a large scale &
  • Atmospheric CO2 on comparatively low scale.

Globally a 20% increase in mangroves area may create approximate 6669000 tones sink for CO2 per year. Similarly a 20% increase in sea-grass area may create approximate 82400 tonnes sink for CO2 per year. Indian mangroves are able to sequester about 1.5 metric tons of carbon per hectare per year. It has been observed that sea grasses together with salt marshes and mangroves are able to capture up to 70% of the organic carbon in the marine realm.

Mangroves & other coastal ecosystem are the excellent habitat of wide variety of marine flora, fauna and carbon. They can sequester carbon at very high rate and can store carbon for 100 to 1000 of years approx. Therefore, Coastal Ecosystem are also referred as ‘BLUE CARBON’. Although they comprises only 0.2% of the ocean surface, but can exhibits 50% of the ocean’s capacity.

The coastal ecosystems of India comprise more than 6000 km2 mangrove areas. Mangroves provide more than 10 percent of the essential dissolved organic carbon. Despite of its lots of benefits, they were vastly degraded in last 40-50 years with a rate of approx. 25% and this indicates significant loss of stored carbon. The reason behind that was, they were viewed as economically infeasible & mosquito infested wasteland, in past. Therefore, they were continuously vanished for development of industries and fulfilling the demand of fuel by the local communities.

Mangroves mainly attract the attention of most of the countries aftermath of the 2004 Indian Ocean tsunami. The December 2004 tsunami hits the Indian coastal communities & coastal resources very badly. This arise the need of improved, long term & maintained coastal ecosystem.

A thick layer of mangrove would help in slowing down the destructive wave action of natural disaster such as tsunami and thus protecting coastal communities & resources from the damaged caused by tsunami.

According to a study (2011) by the National Centre for Sustainable Coastal Management (NCSCM), almost 40% of the Indian coast is subject to coastal erosion. Coastal Ecosystem (Sea grasses, salt Marshes, Mangroves and Wetland) are the habitat of continuous sequestration and storing of carbon in soil. Thus, it offers coastal protection through wave attenuation and erosion prevention. Mangroves, beaches and coral reefs helps in controlling
coastal erosion, shoreline change and also serve as a natural defense against coastal hazards such as storm surges, cyclones and tsunamis.