Ecologists at the Kruger National Park are puzzled over the recent spate of crocodile deaths, the park's management said on Wednesday.

Veterinary surgeons, scientists, researchers, rangers and managers met in Skukuza in the Kruger National Park on Tuesday to discuss the discovery of at least 30 crocodile carcasses in the Olifants River area last Thursday.

"We don't have the answers as to why these crocodiles are dying," said the Kruger National Park's Head of Department for Scientific Services, Danie Pienaar.

A carcass was first spotted by trail rangers. It had distinctive yellow-orange hardened fat in its tail.

During an aerial survey over the entire length of the Olifants River, 30 crocodile carcasses were discovered in various stages of decomposition, he said.

Tissue samples of the yellow-orange hardened fat were taken and sent by the Kruger National park to the University of Pretoria's Onderstepoort for further analysis.

Pienaar said: "It is believed at this stage that the yellow-orange fat is a condition known as Pansteatitis which is usually associated with the consumption of rotten or rancid fish.

"We are not sure, what caused this condition in the Olifants Gorge as there were no recent fish kills reported," he said.

The problem was being investigated and nothing had been ruled out as its cause.

"Although a clear cause/effect relationship cannot be found, it is clear that the Olifants River system is strained beyond it capacity to deal with this level of stress."

Pienaar said the Olifants River was the most polluted river in the park and the system had experienced further strain from the Massingir Dam that has pushed back into the Olifants Gorge, causing sediments to be deposited.

Sapa