The UK’s commercial fishing industry is currently experiencing a number of serious challenges.
However, a study by the University of Plymouth has found that managing the density of crab and lobster pots at an optimum level increases the quality of catch, benefits the marine environment and makes the industry more sustainable in the long term.
Published in Scientific Reports, a journal published by the Nature group, the findings are the result of an extensive and unprecedented four-year field study conducted in partnership with local fishermen off the coast of southern England.
Over a sustained period, researchers exposed sections of the seabed to differing densities of pot fishing and monitored any impacts using a combination of underwater videos and catch analysis.
They found that in areas of higher pot density, fishermen caught 19% less brown crab and 35% less European lobster, and their catches of brown crab were on average 35 grams per individual (7%) lighter.
The effect on marine species was also significant with two ecologically important reef species, Ross coral (Pentapora foliacea) and Neptune’s Heart sea squirt (Phallusia mammillata), 83% and 74% less abundant respectively where pot density was higher.
Researchers say the study provides evidence of a pot fishing intensity 'threshold’ and highlights that commercial pot fisheries are likely to be compatible with marine conservation when managed correctly at low, sustainable levels.
The study was carried out by academics from the University’s School of Biological and Marine Sciences, with funding from Defra and the Blue Marine Foundation and working with the Lyme Bay Consultative Committee.
It builds on an interim report published by Defra in 2019, and research published in October 2020 which used previously unseen footage to show the environmental impacts of pot fishing.
