Restricting the amount of inshore potting for crab and lobster within marine protected areas (MPAs) can generate a “win-win” for both fishermen and the marine environment, according to the first major study exploring the issue.
The study showed that crab caught in areas of low potting levels were of greater average weight, meaning that there was a potential incentive for fishermen to fish less.
However, in areas consistently exposed to medium and high levels of potting, the crab weighed less than those caught in areas with low potting and unfished control areas.
The experiment in Lyme Bay was conducted by the University of Plymouth, and funded by Defra and the Blue Marine Foundation. It found that in areas of low potting intensity the industry was operating in a way that had little impact on seabed species or economically-important shellfish.
The only species to show any potentially adverse effect from low potting levels, compared with no fishing, was Ross coral, though this is highly sensitive and one of the species hit hardest during the 2013/14 winter storms
The extent to which different forms of fishing are compatible with MPAs has long been a subject of debate. In Lyme Bay, the banning of dredging and trawling in what became at the time the largest MPA in the UK led to a significant recovery of seabed life and fish and shellfish stocks, but the question remained just how much fishing with pots – a significant practice around the UK coast – could undermine that recovery.
The new report also talks about the amount of pots being used by fishermen under a voluntary code is having little impact on the marine environment, but if commercial intensity were to increase above a measurable “threshold” then reef species that have started to return following the ban on trawling could be negatively affected.