Water probed after hundreds of Kruger crocs die

The perplexing deaths of hundreds of crocodiles in the Kruger National Park may have stumped South Africa's leading scientists, but Danie Pienaar believes it has also created awareness about this predator's vital role in ecosystems.

"It's mostly children who get really excited about these big crocodiles because they're magnificent and old like dinosaurs," said Pienaar, the head of scientific services at Kruger Park.

"And we should get really excited about them. They're not these horrible beasts lurking around trying to eat you. They play an important role in the system, and if you're happy to lose things like big crocodiles, what else are you willing to sacrifice?"

One of the goals of the newly launched Consortium for the Restoration of the Olifants Catchment (Croc), a gathering of about 40 of SA's top researchers, scientists, conservationists and wildlife pathologists, is to raise the profile of crocodiles, said Pienaar.

Croc will focus on unravelling the mystery behind the deaths of more than 160 crocodiles - the real figure is believed to be double this - in the Olifants Gorge since May this year as well as saving the Olifants river system, one of SA's hardest-working - and most polluted - systems.

"We've now got to put together specialist groups [within Croc] that will be looking at different issues in more detail around water quality, crocodiles and the fish. People who work on the Olifants have been saying for a long time that there's a big problem coming with the Olifants. By the time the crocodiles are dying, things have gone way too far. We want to look at the bigger environmental problem, which we believe is growing in all our rivers, around water quality."

Led by SANParks, Croc includes experts from the Water Research Commission, the universities of North West and Pretoria, as well as the Department of Water Affairs and Forestry.

It also hopes to draw in expertise from the neighbouring Limpopo National Park in Mozambique. Post-mortem results show the crocodiles died of pansteatitis, or body fat hardening, which leads to starvation.

There is also concern over rural communities in SA and Mozambique who source untreated water from the river. "Around Mozambique's Massinger Dam [where the wall was recently raised] people eat the fish and drink water from the dam, but if the [Olifants] river keeps deteriorating, we could start seeing problems in humans as well. We've seen cholera outbreaks in Zimbabwe and now South Africa."

Dr Peter Ashton, an aquatic ecologist at the Council for Scientific and Industrial Research, and a member of Croc, said the Olifants had been "used and abused" for the past 50 years.

He believes acidic mine pollution from abandoned and closed coal mines on the escarpment, raw and treated sewage pumped into the river system from surrounding municipalities, as well as contamination from agricultural chemicals and domestic effluent could all be placing the Olifants system under extreme stress.

"All these could be adding up. You start to see sensitive organisms disappearing and the character of the river changing. We're putting all our heads together now to see how this catchment is being worked, where the problems are and how these are impacting the river. The river is functioning as a kidney in the landscape."

Croc represents the largest grouping of aquatic specialists. "We can't just leave it up to the authorities," he said, because staff are lacking.

Ashton hopes to see the same action on other hard-working rivers in SA. "They are all heavily utilised. We need to look carefully at how they supply water, and transport and dispose of treated effluents."