AIR CURTAIN BID TO STOP JELLYFISH ATTACKS

A £68,155 experimental bid to curb the threat of jellyfish to fish on salmon farms has won backing from Western Isles Enterprise in the aftermath of heavy losses to jellyfish attacks over the summer.

The scheme involves using a curtain of air bubbles streaming up from the seabed around the salmon cages to deflect the tidal shoals of jellyfish away. It has been put forward by Western Isles Seafood Company, based in Marybank, Stornoway, which is a subsidiary of the Norwegian producer Fjord Seafood ASA.

The farming of fish like salmon in sea cages leaves them exposed to losses from attacks by jellyfish and algal blooms. Scottish Executive figures say that four million fish, worth around £32 million, were lost over the last two years. In August 2002, WISCO alone lost 625 tonnes of salmon, worth £1.8 million, at two Lewis sites after jellyfish attacks.

WISCO employs about 50 people farming Atlantic salmon from four sites on the Western Isles and one in Ross-shire. It also has contracts with two contract growing companies in Skye and Lewis as well as producing smolts on the Western Isles.

Now the company hopes the air curtain scheme will work and remove the unpredictable risk which its production plans face from blooms and jellyfish. Preliminary work is intended to be completed by February with full-scale tests underway by April/May on one of the firm's sites. If the results are favourable, the defensive shields of air will be put in place before the summer/autumn when the chance of attacks is at its highest.

The total cost of the project is £68,155 with WIE putting in £44,000. Two years ago, WIE backed an earlier research and development project by WISCO to investigate the use of a type of fish called Goldsinny Wrasse to act as a biological control against sealice infestation on salmon farms. This was successful and the system is now in use on two sites.

WISCO's technical manager Mr Regis Philippe said that at present there was no reliable system of defence against jellyfish attack. The huge shoals drift with the tide and envelop the salmon in the cages, killing by poison or suffocation.

Taytech Ltd, the firm involved in devising the equipment, has been testing out the best combinations of equipment and these will be taken out to the test site in early 2003. Stirling Aquaculture and Environmental Services of the Institute of Aquaculture, Stirling University, will provide an independent assessment of the project through a 12-month monitoring programme.
 
Mr Donnie Macaulay, WIE's chief executive, said the enterprise company was deeply committed to supporting the development of innovative and successful ways of dealing with problems facing industries based on the Islands. "In a highly competitive global market, the Islands have to be in the forefront of developments to maintain their market share," he said.