The Lyme Bay experimental potting study

Abstract

It was some time in the early 1990s that people began to speak about the need to protect ‘England’s coral garden’ - the reefs of Lyme Bay. Newspapers carried images of the rich habitats for fish, shellfish and rare species of coral and sea fans revealed below the waves. Local fishermen, conservationists, divers and anglers, among others, found themselves part of a rising chorus of concern about evidence of damage caused to the reef habitat by trawls and scallop dredges. Eventually the many local and national expressions of concern prevailed and the government chose finally to close 60 square miles of the bay to mobile fishing gears in 2008. I was privileged to be involved in a minor way in documenting that dramatic first chapter of the story, a milestone in nature conservation and the management of inshore fisheries in Britain, in my former role as environment editor of the Daily Telegraph. What I will call the second chapter of the story, documented here, began shortly after the formation of our new charity, the Blue Marine Foundation, in 2011 when we at BLUE came to Lyme Bay to hear how things were going in what had become, in effect, Britain’s largest multi-use marine national park. Though by then there was evidence that the reef habitats were recovering, all was not going as well as expected for the environment or for the static-gear fishermen still entitled to fish there. Despite the original Statutory Instrument and the subsequent designation of some 90 square miles as an EU Special Area of Conservation the place didn’t yet appear to be being managed to the satisfaction of either fishermen or conservationists. The prohibition of dredging and bottom-trawling had the unexpected effect of making the reefs a magnet for a concentration of static gear - pots and nets – because the static gear no longer got towed away by the mobile gear, so the closed area was a safe place to leave it to work. Was there an impact from this over-concentration of fishing gear upon some local fishermen’s landings? Some said their landings had halved in recent times. We were concerned that, as this was happening, there might also be an impact upon the corals, sea fans and other benthic life that was supposed to have been protected by the closure to mobile gears. This report confirms that our suspicions were correct: that unregulated, high levels of sustained potting effort could impact some of the reef’s distinctive marine life. The study also tested the assertion, from fishermen in the four ports, that their small-boat methods were sustainable but those of larger boats from outside the area were not. These results provide evidence that the current way of life for small-boat pot fishermen operating in the Lyme Bay and Torbay Special Area of Conservation (SAC) is consistent with its objectives. A maintenance of the status quo should ensure long term sustainability of this fishery. Back in 2012, BLUE and the fishermen agreed to set up a Consultative Committee and to try to achieve three ‘wins’ for fishing and conservation: 1) A win for the fishermen to provide them and their heirs with a sustainable living; 2) A win for conservation in the protection of the Lyme Bay ecosystem and its stocks of seafood; 3) A win for the communities around the bay. But how were we to measure success? Particularly in achieving the crucial second aim, on which everything else depended? We wanted to guarantee the fishermen from the four local ports what they wanted, a right of access to the resource as long as it could be proved that what they were doing was sustainable. Nobody could tell us, however, what density of potting that was and what level would impact not only the target species of lobster and crab but damage the reefs and their corals. Luckily, Dr Bob Watson who was then chief scientist at Defra was persuaded that this was precisely the kind of information that would be valuable as Britain developed its network of marine protected areas, most of which would continue to be fished. So, the potting study began – with a secondary aim of seeing if there were any ’spillover’ effects beneficial to fishing from the small 500m x 500m areas where potting had been removed as control areas for the experiment (something it has not been possible to prove). The study has had its challenges: nobody anticipated all the pots and markers being washed away in the storms of the winter of 2013/14 with an impact on the seabed and data comparisons which necessitated a year’s extension to the project, but we are delighted that it has had some clear results. These show a ‘threshold’ at which fishing effort begins to be damaging to crustacean populations and the reef environment. We did not anticipate the other fascinating finding: that lower effort would result in a higher quality of catch. This completely vindicates the ‘high quality, low volume’ fishery the Lyme Bay Fisheries and Conservation Reserve has tried to encourage in its voluntary code of conduct. We did not anticipate such clear findings and we thank Adam Rees and all at the University of Plymouth for their analyses, and the funders at Defra for their commitment to the science. These results will enable the Lyme Bay Fisheries and Conservation Reserve Consultative Committee to manage the Lyme Bay and Torbay Special Area of Conservation (SAC) with confidence into the future. These results also provide invaluable advice for the managers of other marine protected areas, both around Britain’s coasts and elsewhere.