JAPANESE SEAWEED: POTENTIAL DAMAGE (Hansard, 25 January 1979)

§ Baroness STEDMAN

Porphyra Tenera is an edible seaweed which, as far as is known, grows only in the Pacific. The Japanese seaweed which arrived on the South Coast of England at some time between 1971 and 1973 is Sargassum Muticum. Its greatest concentration is in the Solent, but isolated colonies have been found growing in places from the Yealm in the West to Brighton in the East. The DOE is investigating unconfirmed Press reports of an outbreak in Kent. Sargassum Muticum does not currently present a serious hazard to navigation or to fishing. It can, however, spoil amenity beaches and it can immobilise outboard motors and impede the passage of small sailing boats. Clearance is a local authority responsibility.

Since 1973 the Natural Environment Research Council and the Department have been sponsoring studies of the growth and spread of the weed and the possibility of biological or chemical control. Towards the end of 1976 it became apparent that no effective biological or chemical means of control was going to be found in the near future and mechanical clearance seemed to offer the best possible hope for containment. Accordingly a research development contract was let to Portsmouth Polytechnic. Up to now the Department have provided over 70 per cent. of the cost and local authorities have contributed the rest. For 1979 it is hoped that the local authorities will increase their contribution to 50 per cent. The contract has resulted in the design and construction of an effective trawl suitable for use from any standard inshore fishing boat; and a purpose-built craft of somewhat higher efficiency will be ready early this year. Research on cutting and suction devices is well advanced.