Evaluation of Catch Performance and Environmental Impact of Technical Gear Modifications for a More Sustainable Scallop Dredging Fishery

ABSTRACT The scallop fishing sector is central to UK fisheries. Traditional dredging with Newhaven dredges poses ecological risks, creating pressure to adopt more sustainable practices. This study assessed the catch and environmental outcomes of modified scallop dredge designs aimed at reducing environmental impact without compromising catch efficiency. Four gear designs were tested: (1) N‐Viro dredge with conventional belly bag, (2) N‐Viro dredge with skid belly bag, (3) Newhaven dredge with skid belly bag, compared to the (4) standard Newhaven dredge with conventional belly bag. Results showed that the N‐Viro dredge alone did not increase catches of market‐sized king scallops ( Pecten maximus ); however, pairing it with a skid belly bag improved catches by 14%–19%. The N‐Viro dredge reduced undersized scallop catch by 42% and stones by 67%, with further reductions when combined with a skid belly bag. Bycatch levels remained unchanged. Fuel consumption fell by 30% with N‐Viro dredges, equating to annual CO 2 reductions of 164,571 kg CO 2 ‐e/year for vessels over 15 m and 37,235 kg CO 2 ‐e/year for vessels under 15 m, alongside annual fuel cost savings of £46,250 and £10,465, respectively. Seabed impact assessment indicated that skid belly bags reduced gear footprint by 55%, with the lowest impact from the N‐Viro dredge with skid belly bag. These findings demonstrate that combining N‐Viro dredges with skid belly bags can substantially cut environmental impacts and emissions while maintaining catch efficiency, offering a promising pathway towards more sustainable scallop dredging in UK waters.