(Story dated: Tuesday, February 17, 2004)

Concerns have been raised over increasing numbers of non-native fish in Orkney.

Two species of fish, previously unknown to Orkney, have become established in the County. Stoneloach have been present in the Durkadale Burn in the north Mainland for the past 15 to 20 years.

But minnow appear to have arrived in the same watercourse within the last two or three years.

The movement of any species of plant or animal, including fish, to areas where they would not normally be found, is of major concern to Scottish Natural Heritage (SNH) due to potential adverse impact on native wildlife.

Area officer for SNH in Orkney, Julia Partridge, said: "While there are no legal restrictions on the movement of either Minnow or Stoneloach, it is commonly considered bad ecological practice. As with most non-native introductions, it is almost impossible to quantify exactly what the impacts will be once these fish have been translocated to other watercourses. It is extremely likely that both species, but particularly minnows, will compete with salmonids for food or space.

"Orkney has an internationally renowned brown trout and sea trout fishery, and it is therefore important that people are aware of the potential impacts associated with importing fish species which are not native to the area. This raises the whole issue of species inadvertently being introduced to areas where they would not normally be found. Before releasing any species at all into the wild, we would always urge people to check carefully whether it already occurs naturally in the area."

Sandy Kerr, member of SNH's North Areas Board and of the Orkney Trout Fishing Association, said: "We know that both minnows and stoneloach are now established in the Durkadale Burn, but we are uncertain as to whether they may be present in other waterbodies within the county. We would be interested to hear from anyone who has seen either species elsewhere in Orkney, so that we can build up a picture of how far these fish have spread."