Mass deaths of Caspian seals still a mystery

ALMATY, Kazakhstan, May 29, 2000 (Reuters) -- Seals have stopped dying en masse off the shores of Kazakhstan's Caspian Sea but the exact cause of an epidemic that killed thousands remains a mystery, the Kazakh natural resources ministry said on Monday.

"Studies conducted by Russian specialists at the Fisheries Institute in Astrakhan showed that the pathological processes observed in the Caspian seals was cumulative polytoxosis," the ministry said in a statement.

This could indicate an overdose of toxins from water, reeds or fish, either consumed over a period of time or in one large sudden dose, veterinarians say.

The final cause of death can be identified only after results are obtained from analyses being conducted by Kazakh laboratories, the ministry said, adding that sulphur found in the seals' bodies had also been sent for analysis.

Specialists have been mystified in recent weeks by the death of thousands of Caspian seals, which often crawled from the sea to die, leaving a trail of carcasses off Kazakhstan's western shores.

More than 3,600 seals have perished over the past two weeks, but fewer of the animals are dying now, the ministry said. About 420,000 seals are estimated to live in the Caspian Sea.

Experts had earlier said samples taken from dead seals indicated either pasteurolossis -- caused by the micro-organism responsible for plague -- or mammal distemper. The latest suggested diagnosis has, like these earlier ones, yet to be confirmed.

The government has said the deaths are not due to drilling projects in the oil-rich Caspian. It said in the statement that almost 20 million tenge ($140,000) had been allocated for conservation projects in the region.