Ecological treasures ... unlimited
Two recent surveys have uncovered globally significant new information from the Andaman and Nicobar Islands. PANKAJ SEKHSARIA writes.
Timber loading at Hut Bay (this picture was taken in 1988) ... now a ban on tree felling
FOR a field biologist of any kind, be it marine, herpetological, or botanical, the Andaman and Nicobar islands are the ecological equivalents of the well known "magician's hat". Put in a little effort, some resources and time and out comes a fascinating "rabbit". So much so that every time there is a field study or survey in the islands some new information becomes available. Two recent surveys in the islands, one regarding corals and another the Giant Leatherback Turtle prove just that. Coming in quick succession in the last few months, both the findings are being considered as being globally significant. In April 2001, an international team comprising Indian, British and Australian scientists conducted a 10-day remote sensing and rapid survey based study of the coral reefs of the Andaman islands. Thirteen sites were surveyed as part of this joint project of the Government of India (GOI) and the United Nations Development Program Global Environment Facility (UNDP-GEF). The surveys recorded 197 species of coral, of which, an astonishing 111 were new finds for the A&N. It is indicative of both: how little these islands have been studied and importantly, the actual richness of the diversity here. One species of coral was a new find for science and another one, found commonly during the dives, had earlier been reported only from the Philippines. The potential of what lies ahead is evident from the fact that this huge discovery came from only 10 days of work in13 Andaman sites. The Nicobars that are likely to spring many surprises in store were not looked at, at all.
It is being suggested that the total number of coral species in these islands should touch around 400. This would then compare to the richness of the coral triangle, the area of the greatest marine diversity on earth, comprising the Philippines, Indonesia and Papua New Guinea. The A&N lie just northwest of this coral triangle and at 400 species, would be supporting about 80 per cent of the diversity found in the coral triangle.
The study reported that the reefs in the Andamans were more diverse than expected and less impacted than had been feared by other scientists working within the Indian Ocean region. A surprising find was that the reefs were hardly affected by coral bleaching hat had devastated coral reef systems worldwide in 1998. Another threat, the possible infestation by the Crown-of-thorns starfish was also non-existent. The conclusions, as the authors point out, are extremely significant. Not only are the coral reefs here globally significant in terms of coral reef diversity, their extremely healthy status may prove the area to be an important stronghold for corals in the Indian Ocean region and provide a reliable source for natural seeding and rehabilitation of other impacted coral reefs here.
Good coral populations indicate a healthy marine system, which in turn is very critical for other species that inhabit the oceans, sea turtles for example. The other significant finding is regarding the nesting populations in the islands of the Giant Leatherback Turtle (Dermochelys coriacea), the largest marine reptile. Conducted by the Andaman and Nicobar Islands Team (ANET) the study is part of an of the ongoing GOI-UNDP Sea Turtle project in the country. The first authenticated report of the Giant Leatherback nesting in the islands was made as recently as 1978, when Satish Bhaskar of the Madras Crocodile Bank Trust (MCBT) conducted his turtle surveys here. MCBT and ANET continued with detailed and more intensive surveys at regular intervals, the latest of which was completed in 2001. Writing in the recent issue of the sea turtle conservation newsletter, Kachhapa, Harry Andrews of ANET and Kartik Shanker of the Wildlife Institute of India (WII), explain "that the total population (based on the latest surveys) of adult female Giant Leatherback turtles that use the beaches in these islands for nesting exceeds a 1,000 individuals". Only three other colonies in the world are reported to have more than 1,000 individuals, clearly indicating that this island group is very critical for the long-term survival of this species. The status of the Leatherback, has in fact been recently changed from endangered to critically endangered. The threats to the turtles in the A&N are manifold to say the least. A pertinent example is observations in Great Nicobar island, the most important of the Leatherback nesting sites in the A&N. During the 2000-01 nesting season, a staggering 40 per cent of the nesting Leatherbacks had boat propeller cuts on their flippers, necks and carapaces, thanks mostly to the heavy ship and boat traffic from South East Asia that transits just south of the Nicobars. Andrews further reports that between 1981 and 2000, at least 21 beaches (including five in Great Nicobar itself) that were regularly used by different species of sea turtles have been completely mined away for the booming construction industry in the islands. It has also been estimated that feral dogs predate nearly 70 per cent of the eggs and hatchlings of the sea turtles in these islands. Given this scenario, the chances of these and other species of turtles seem rather bleak.
The root of the issue ... The impact of sand mining erosion on the Hut Bay beach, little Andaman.
Some direction and hope, has in fact, come from an unexpected source. The Supreme Court recently passed landmark orders for the conservation and protection of these islands. As a consequence, tree felling in the islands has been completely stopped, sand mining from the beaches of the islands is to be reduced over a period of the next few years, forest encroachments are being removed and steps are being initiated to limit the immigration of people from mainland India. The importance of this can be ascertained from the fact that the population of the islands has increased nearly seven times from about 60,000 in 1960 to an estimated 400,000 today. The impact that this is having on the fragile environment can well be imagined. Though sand mining needs to be reduced much faster and far more drastically, the court order has initiated the first step in the right direction.
For the coral reefs too, there will be many benefits. An illustration of this is the 1989 study of the Indian National Trust for Art and Cultural Heritage (INTACH), titled "An investigation into the effects of siltation, logging, blasting and other human derived damage to the coral islands in the Andaman and Nicobar Islands". Of the various points chosen for the study along the coast of Little Andaman island, the maximum percentage of dead coral was found around the jetty at Hut Bay, the island's main town. The relative abundance of live coral here was reported to be only about 12 per cent. The reasons were clear. There was large scale logging and a huge timber yard in the vicinity. Soil erosion was high and the sea water was dark and muddy, preventing light penetration and affecting the growth of corals. Mud accumulation on the sea bed was found to be very high and silt accumulation was also seen on the corals themselves. Many such interesting and significant studies have never been considered by the bureaucrats and planners when the future of the islands is planned. That this knowledge should become part of the information base when decisions are taken is very important. The survival of the biological wealth of the islands and also of the human communities that live here will critically depend on that.
The rabbits too, will keep coming out!
The writer is a member of the environment action group Kalpavriksh. He is based in Pune and writes regularly on issues of livelihood, conservation and the environment.
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