Dolphin squeezed out of existence by activity on river

ON Wednesday, August 8, there was a sad story on RTÉ Radio’s News at One. It was the announcement that the Yangtze River dolphin was extinct.

They are, or were, freshwater dolphins of a pale, off-white colour up to about 2.5m in length with a long, duck-like beak. They were also called baiji. They lived in a 1,700km-long stretch of the Yangtze upstream from Shanghai. They ate large fish, particularly catfish.

Although most dolphin species live in the sea, there are some other river dolphins in the world, such as species in the Amazon, the Ganges and the Indus in Pakistan. They are all more or less endangered.

A thorough survey of the Yangtze was carried out between 1997 and 1999. It found just 13 individual dolphins. The last confirmed sighting was in 2002, though there have been unconfirmed sightings since. There was a rather ineffectual effort to breed them in captivity. The last captive animal, a male called Qi-Qi, died, also in 2002.

Recently a multi-national survey team under the direction of Dr Samuel Turvey, a conservation biologist from the Zoological Society of London, came to the conclusion that they were extinct.

The Yangtze River dolphin is the first large vertebrate to become extinct in recent times and the first whale or dolphin species to have been exterminated as a result of human activity. So it was a significant news item and RTÉ were quite correct to include it in their bulletins.

The news should make us all stop and think about the threats to biodiversity on the planet and the effect the human species is having on nature.

THE dolphin was not hunted to extinction. It just had the misfortune to live in the wrong river. The Yangtze valley holds between 10 and 12% of the total human population of the planet. It has a number of hydro-electric dams, extremely heavy boat traffic and it is also intensively fished.

Essentially the dolphin was squeezed out of existence by the sheer number of people sharing its river. The last survivors were probably hungry and bewildered and their bodies scarred from being hit by propellers.

And unfortunately stories like this are not confined to places on the other side of the world. There is accumulating evidence that human activity in Ireland is having a serious impact on wildlife.

There are stories of emaciated seals and declining numbers of sea birds around our coasts as a result of commercial over-fishing. Changes in farming methods have led to the extinction of the corn bunting and the near extinction of the corncrake in this country.

For the past 30 years I have spent quite a lot of time cruising by boat around our inland waterways. One of the odd phenomena I have noticed is a dramatic rise in the number of sea birds on our larger inland lakes.

Lough Ree, for example, has acquired in recent years a colony of cormorants that is several hundred strong. It also has breeding colonies of black-headed gulls, herring gulls, lesser black-backed gulls and arctic terns.

It only occurred to me quite recently that this has probably happened because there are far more fish in the lake than there are in the sea.

Biodiversity is not just an ethical matter, it’s also a practical one. We need the rest of nature. If we continue to reduce it we will also perish in the end. The obituary of the Yangtze River dolphin should be an alarm call.

* dick.warner@examiner.ie

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