Nature gurus slam alien crayfish investment idea

Environmentalists have slammed Economic Development MEC Lynne Brown's announcement that the province will invest R500 000 in developing a hatchery for alien freshwater crayfish.

They say the marron crayfish, which can climb over fences, walk across land and live for several days out of water, pose a risk to the natural environment should they become established in the wild.

No risk assessment or environmental impact assessment (EIA) has been done for the proposed hatchery. The first the environmental authorities knew about the venture was when Brown announced it in her budget speech last week.

Marron crayfish, Cherax tenuimanus, have been declared a noxious species in Victoria, Australia.

Irene de Moor, a research associate at the SA Institute of Aquatic Biodiversity in Grahamstown, did an assessment for the department of agriculture in 1999 on the potential environmental impacts of four alien freshwater crayfish, including marron. She recommended that none of the species be allowed to be imported into the country.

However, many years prior to the study, several provincial nature conservation departments had already granted permits for marron to be imported and bred in the country.

De Moor said although marron posed the least environmental threat of the four species, it was "clear that environmental damage has outweighed economic benefits accruing from the importation of this species". Further importation should not be allowed, she said.

Roger Bills, a freshwater fish specialist from the same institute, said the fact that marron had not yet established themselves in the wild did not mean they would not do so eventually.

He believed existing marron operations should be shut down.

"The problem with any alien species is that it takes a very long time to see the impacts they have on the indigenous environment. It may be 20 or 30 years before they establish themselves properly, and another 20 years before one can see the environmental changes they cause. By that time it will be too late to do anything about it," Bills said.

He added: "Once they are established in the river systems, you will never get rid of them. I don't understand why the nature conservation authorities even consider allowing alien species introductions."

Kas Hamman, director of biodiversity for CapeNature, said his organisation would not allow the new hatchery to be developed without a full EIA and risk assessment being done.

James Visser, the proponent of the hatchery, says marron is quite safe. He has farmed them here for the past 14 years, with permits from nature conservation. At the time there was no requirement to do an EIA.

He said there had been several instances of marron getting out of dams, but they had never established themselves in the wild as they were "predated on 100 percent".

"The necessary requirements were met for the permit conditions. I am running a hatchery at the moment, so there is really no difference," Visser said.

Instead of involving a big company in developing the new hatchery, he had chosen to see the marron industry grow in the small sector.