New scallop dredge designs have potential to reduce environmental impact

Seafish, the authority on seafood, has just announced the results of the scallop dredge competition, launched in September last year to encourage new and innovative designs for a dredge that was commercially efficient, but also reduced environmental impact on the seabed. The competition was sponsored by members of the UK Scallop Group, reports www.megafishnet.com with reference to Seafish.

Entries were encouraged from the fishing industry in collaboration with engineering and technology businesses, Universities, colleges and other organisations. The selected designs were to be tested onboard the RV Prince Madog, the Bangor University research vessel, during summer 2010.

Three designs met the selection criteria and made it through to the sea trials stage, but of these three, one manufacturer failed to have the full scale prototype gear ready in time for the trials. As a result two designs were tested by scientists and technologists from Seafish and the School of Ocean Sciences at Bangor University, onboard the RV Prince Madog.

The first was an N-Viro dredge (spring tine frame), presented by Richard Gidney of Deeside Marine Kirkcudbright. This new toothed scallop frame design utilises individually sprung tines, instead of the traditional sprung tooth bar which moves as one. It also has an innovative ‘rolla' belly, instead of chain mail, incorporating rollers mounted on axels, joined by links, to form the belly.

The second was an alternative belly design dredge, presented by Stewart Adam of Oban Scallop Gear Ltd. This design uses tough conveyor belt material to replace the metal chain bellies thereby reducing the weight of the bag.

The performance of both new designs was compared with that of the standard Newhaven dredge and the results analysed against the criteria set out in the competition rules.

"There was no outright winner," said Mike Kaiser, Professor of Marine Conservation and Ecology at Bangor University and a Seafish Board member, who chaired the judging panel. "After looking at the results carefully we unanimously agreed that although each design had its own merits, with design features worthy of further investigation, an award could not be made as the two experimental designs did not offer significant improvements in terms of the environmental effect of the gear, when compared to the standard Newhaven dredge presently in use throughout the industry.

"But on the positive side there were indications that some aspects of the technology developed by the participants had the potential to reduce the environmental impacts of scallop dredging. In particular there were indications of a reduction in the quantity of stones retained in the experimental designs when compared to the standard dredges," said Mike.

Mark Greet, Chairman of the Scallop Association said, "This is only one of a number of initiatives being undertaken by the scallop industry to change, develop and improve its environmental credentials. The UK Scallop Group is representative of the industry as a whole and it is hoped that through continued collaboration with manufactures, engineers, scientists and gear technologists that the innovations made so far can be developed further and other ideas investigated."

A full report on the sea trials will be available shortly. For further information on the trials contact Bill Lart at w_lart@seafish.co.uk or Mike Humphrey at m_humphrey@seafish.co.uk