Ireland boasts one of the last sanctuaries for bluefin tuna, but US marine scientists have warned that it could be wiped out by the activities of foreign vessels.
A 40 metre Spanish purse seiner was targeting shoals of the migratory fish inside the six-mile limit off south Donegal last week, according to the scientists who were participating with Bord Iascaigh Mhara (BIM) in a research programme on the fish.
Mr Andre Boustany, marine biologist at Stanford University's tuna research and conservation centre, said that at one point the purse seiner, Nuevo Elorz, steamed very aggressively towards the vessel he was working on.
It is believed the purse seiner may have Japanese business links. A Naval Service spokesman said the vessel had been picked up by satellite and was en route south to Spain at the weekend.
Both the Stanford University scientists and deep sea anglers have called on the Government to impose a 200-mile sanctuary for the fish in these waters. Bluefin tuna are one of the most expensive fish in the world when caught fresh, with premium prices paid on the Tokyo market.
Known to record "bursts" of 50 knots, the fish have never been harvested commercially off this coast. In the past two years, they have become "friendly bounty" for a developing "sport" fishery in Donegal and Connemara.
The new "sport" fishery has been attracting big game anglers into the west and north-west - wealthy customers who normally fly to Kenya, the Azores and Cape Verde islands to catch marlin and yellowfin tuna. The activity is based on catch and release - no fish are kept, under the voluntary code of the Irish Game Fish Association.
Mr Adrian Molloy of the Naomh Cartha, who has been one of the pioneers of the activity, says it has extended the tourist season in south Donegal and he is able to fill some 300 extra bednights in the Kilcar area alone.
Several sea angling vessels in Connemara are also involved in the autumn fishery, which has been supported by a BIM diversification programme.
The Stanford University scientists have been working with the sea anglers on a tagging programme for the fish, to assess the state of the stocks.
The Stanford University team refer to a 1998 socio-economic study of the sport fishery for bluefin off the north Carolina coast in the US, which found that the activity was worth some $6 million annually to the local economy.
It also extended the tourist season to a year-round activity. Ireland could build up a similar base if a proper management policy was introduced, which ensured that there was no commercial fishing for the species, they state.
Mr Adrian Molloy, a former commercial fisherman, said Spain could not claim traditional rights to the fishery here. "We have made huge mistakes with our resources in the past, and this is an opportunity to take a developing fishery and manage it properly," he said.
