Cleaning up on crayfish

A cross-Border initiative has just over a year to find out whether farming crayfish in Ireland is commercially viable, writes…

A cross-Border initiative has just over a year to find out whether farming crayfish in Ireland is commercially viable, writes Dick Ahlstrom

Efforts are underway to farm the native white-clawed crayfish, work that may soon lead to the species appearing on a menu near you. A cross-Border initiative began in May to see if methods could be developed to farm Austropotamobius pallipes, a species common across Europe.

"We are looking at the white-clawed crayfish. This is the native crayfish and is the only crayfish species found in Ireland," says Martin Flanigan of the Cross-Border Aquaculture Initiative Team (Cbait), which manages the crayfish project.

Set up in 1999, Cbait is seeking to develop aquaculture in the six Northern Ireland counties and six Border region counties in the Republic. Given its role, it is familiar with most of the bodies and companies attempting to develop aquaculture activity.

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Flanigan was aware of a former trout farm in Dundrum, Co Down, seeking to develop a new project. He also knew of the Republic's first perch farm based in Arvagh, Co Cavan, which has the latest hatchery technology available to it. He brought the two farms together in a project to see if A pallipes could successfully be farmed.

"The object is to take the disused trout hatchery, fix it up and turn it into a dedicated crayfish hatchery," says Flanigan.

Those involved have given themselves about 14 months to see if the species can be farmed in sufficiently large numbers to be able to re-stock streams where it has disappeared.

White-clawed crayfish "are under pressure due to pollution, changed farming practices and different aspects of water usage", Flanigan says, although they are not under serious threat.

Any re-stocking may have to encompass a much wider region, he adds. "One of the big things in the UK and Europe is that imported crayfish have brought with them a fungal infection that is affecting native crayfish."

No crayfish have been imported to Ireland, which thus remains free of the infection, so clean stock grown here could be used for export.

Flanigan's group approached the East Border Region of the Cross-Border Economic Development programme to apply for funding from Interreg, an EU programme which supports European regions attempting to set up collaborative projects. Funds were used to redevelop the Co Down hatchery and begin growing supplies of A pallipes, and also for hiring a Czech expert in crayfish.

THINGS HAVE WORKED well so far, says Flanigan. Native brood stock and wild crayfish from the Coolebrook River in Co Fermanagh have been collected and introduced to the Co Down hatchery.

"They are very interesting creatures," Flanigan says. "The males are quite territorial and will readily cannibalise the juveniles."

Holding tanks were redeveloped to provide nooks and crannies for the adults, something that reduces territorial aggression. The juveniles were also protected so they wouldn't end up as another crayfish's dinner.

Male and female crayfish mate in October and the females then carry 60 to 80 eggs until they hatch the following June.

"We have got juveniles produced and are growing them up as fast as we can on phytoplankton," Flanigan says.

The females hide away during the winter months while the males are "barging around eating, and they are quite territorial. The next stage would be that, by June, we will have a pretty good idea of how to grow these crayfish."

Adult crayfish can live for five or six years and grow to be 10cm to 12cm long, big enough for several to provide a meal for those inclined to eat them. They are eaten in Sweden, Finland, Germany and Australia, to name a few places, but are not consumed in Ireland, Flanigan says.

Asked whether they have commercial potential, he responds: "We don't know. No one is really eating them in Ireland. The table market is something we are going to look into."

In the meantime, the goal is to develop the skills necessary for growing up stocks of juveniles and for breeding adults, as proof that crayfish be farmed commercially.

"We are trying to do a lot in 14 months," says Flanigan.