Asia's dying species threaten man's future

Nirmal Ghosh, Straits Times 16 Nov 07

BANGKOK - ON HIS walks in the Himalayas and the hills of south India, wildlife scientist A.J.T. Johnsingh has noted that quietly, the golden mahseer population is dwindling.

This is no ordinary fish. At the top of the food chain, the golden mahseer is the tiger of the fish species in the mountain streams it inhabits.

But in recent years, its numbers have declined steeply, because of net and dynamite fishing, and the damming and polluting of the rivers it depends on.

Above the mahseer, and often in exactly the same habitat in India and Nepal, is another species which this year was suddenly found to be highly endangered - the gharial, or fish-eating crocodile.

Gharials compete directly with people for fish in the rivers they inhabit and, inevitably, lose. There are now only an estimated 200 breeding adults left in the wild.

Like the golden mahseer and gharial, dozens of species are dying across Asia, often unacknowledged because they are not cute, cuddly or charismatic.

Some, like the Sumatran rhino, may well be functionally extinct in the wild - meaning their populations are so low and so widely scattered that individuals no longer come across others of breeding age. The twilight of a species is usually slow, and as the final darkness falls, also very lonely.

Current documented rates of extinction of species are estimated to be roughly 100 times higher than typical rates in the fossil record, notes the United Nations Environment Programme's fourth Global Environmental Outlook (GEO4) report, just released.

Separately, the World Conservation Union (IUCN) in September released its annual updated Red List of endangered species.

The list is based on information from thousands of scientists in 147 countries who looked at available data on 41,000 species.

They concluded that more than 16,000 are in danger of becoming extinct - 188 more than listed last year.

Extinction is a part of evolution, but studies clearly show human activity is accelerating the process.

The figures are based on what we know. We are certainly losing species without ever knowing they existed somewhere in the food chain of which we are a part.

The GEO4 report identifies loss of biodiversity as a critical environmental challenge if we are to survive as a species ourselves.

The reason is every species lost is a brick yanked out of a wall. Sometimes, one brick dislodges others. The 'infrastructure' of life is affected, and mankind's food and medicine base narrows.

Asia is a critical frontline in this battle - which the GEO4 authors say has yet to be seriously joined in terms either of policy or its implementation.

Subsequent to the GEO4 report, Hong Kong's Ocean Park Conservation Foundation released findings of research which showed 79 species of freshwater turtles - a full 80 per cent of the turtle family in Asia - are endangered.

And at last month's meeting of the IUCN's Primate Specialist Group, Asia appeared as home - or what is left of it - to more endangered primates than any other continent.

Asia has 11 endangered primates, including the Sumatran orang utan, Siau Island tarsier and Hainan black-crested gibbon.

Vietnam alone has four of the 25 most endangered species worldwide. They include some of the most beautiful life forms on the planet, like the golden-headed langur - down from thousands of animals some two human generations ago to only 65 today.

In field research, Mr Ben Rawson - a primatologist with Conservation International in Hanoi - and his colleagues often find that populations thought to be doing fine are actually in dire straits.

There are small candles of hope - like the recent discovery of a population of the highly endangered primate, the grey-shanked douc.

But, generally speaking, 'the more we find out, the worse the situation seems to be', Mr Rawson says.

Sometimes, large patches of forest have no primates left because they have been hunted out; other times, small patches of forest have remnant populations with nowhere to go.

The drivers of this rapid and widespread loss of biodiversity, with entire species in the air, on land, in freshwater and in our seas and oceans dwindling and disappearing, are a complex mix which triggers a domino effect.

They include land use change from forest and open grassland and wetland to agriculture, industry and towns; the replacement of natural forest with low-diversity plantations; changing the geography and hydrology of river systems with dams and reservoirs; and simply direct exploitation of natural resources for food and commercial trade with little real accountability.

Says Dr Johnsingh, currently scientific adviser to the Worldwide Fund for Nature in India: 'When the population of a species goes below a certain level it (extinction) can happen very quickly.'

The answer is not just to legislate more protected areas - which especially in terms of the marine environment is grossly inadequate at less than 1 per cent of total marine area globally.

In the Vietnam example, which is by no means unique in Asia, protected areas remain underfunded and understaffed, and not highly effective at protecting biodiversity, says Mr Rawson.

Biodiversity is undervalued at the policy level, the GEO4 authors argue. 'The values of biodiversity are insufficiently recognised by political and market systems,' says the report.

'Losses of biodiversity, such as the erosion of genetic variability in a population, are often slow or gradual, and are often not seen or fully recognised until it is too late.'