New Delhi: As the world observes Earth Day Thursday (tomorrow), there is not much to cheer for the coastal communities whose primary source of livelihood -- mangroves is under threat due to unchecked anthropological pressures and natural calamities.
The International Union for Conservation of Nature (IUCN), a network of several conservation groups, has set alarm bells ringing by warning that more than one in six mangrove species worldwide are in danger of extinction due to coastal development and other factors, including climate change, logging and agriculture.
Mangroves are salt-tolerant plants of tropical and subtropical inter tidal regions of the world and are extremely delicate and fragile. They host several commercially important species of fish and crustaceans in countries like India and Phillipines providing source of livelihood to the coastal communities.
In its first-ever global assessment on the conservation status of mangroves for the IUCN Red List of Threatened Species released recently, the organisation has also enlisted Sonneratia griffithii, a species of Mangrove found in India and southeast Asia as Critically Endangered, the highest probability of extinction measurement.
The same is the fate of Bruguiera hainesii which grows only in a few fragmented locations in Indonesia, Malaysia, Thailand, Myanmar, Singapore and Papua New Guinea. Eleven out of 70 mangrove species (16 per cent) which were assessed will be placed on the IUCN Red List.
The Atlantic and Pacific coasts of Central America, where as many as 40 percent of mangrove species are considered threatened, are particularly affected, says the study.
In India and Southeast Asia, 80 percent of all mangrove area has been lost over the past 60 years, says the study which estimates that there are fewer than 250 mature trees of the species remaining.
A recent State of Forest Report 2005 shows an extent of 4,445 sq. km. mangrove areas in India, accounting for about 5 per cent of the world`s mangrove forests which are salt-tolerant eco-system.
A state-wise distribution of mangroves out of the total area is 57 percent of the mangroves are found on the East Coast, 23 percent on the west coast and the remaining 20 percent on the Bay Islands (Andaman and Nicobar). Compared to 2003 assessment, there has been a marginal decrease in mangrove cover of the country mainly because of the tsunami that hit Andaman and Nicobar Islands in December 2004.
Gujarat has shown an increase in mangrove cover mainly because of plantations and protection measures.
"The loss of mangroves, will have devastating economic and environmental consequences," says Greg Stone, Senior Vice President of Marine Programmes at Conservation International.
"These ecosystems are not only a vital component in efforts to fight climate change, but they also protect some of the world`s most vulnerable people from extreme weather and provide them with a source of food and income."
The study which appeared in the scientific journal PLoS ONE was carried out by the Global Marine Species Assessment Unit (GMSA), which is part of the Biodiversity Assessment Unit, a joint initiative of IUCN and Conservation International, together with the world`s leading mangrove experts.
"The potential loss of these species is a symptom of widespread destruction and exploitation of mangrove forests," said Beth Polidoro, Research Associate of the GMSA at Old Dominion University and principal author of the study.
"Mangroves form one of the most important tropical habitats that support many species, and their loss can affect marine and terrestrial biodiversity much more widely."
The results of the mangrove species assessment will be placed on the IUCN Red List of Threatened Species in June 2010. The GMSA is largely enabled by the generous support of the New Hampshire Charitable Foundation and Tom Haas.