Saving our scallops: Arran reserve reveals marine protection works

An article by Bryce Stewart, University of York and Leigh Howarth, of our School of Ocean Sciences on The Conversation.

Last summer, on the Isle of Arran, off the west coast of Scotland, we watched an excited young lad walking down to the water’s edge, fishing rod in hand. Sadly, his chances of catching anything were slim to remote.

Once plentiful stocks of cod, haddock and plaice have almost completely collapsed in the Firth of Clyde, the area of sea in which Arran sits, following a century of poor fisheries management.

Nowadays more than 99% of the commercial fisheries landings there are not for fish, but for shellfish such as prawns and scallops, which don’t take a bait.

Motivated by this dramatic change in their local marine environment, two Arran residents, Howard Wood and Don McNeish, formed the Community of Arran Seabed Trust back in 1995. They quickly seized on the idea of using marine reserves – areas of sea where fishing and other extractive uses are restricted – as a way to bring back the marine life they had previously enjoyed as scuba divers.

Reserves had been used to great success in New Zealand and the Philippines, where the benefits appeared to have spilled over to the areas open to fishing. However marine reserves were non-existent in the UK at the time.

Finally, after over a decade of campaigning and building community and scientific support they got their reserve in Lamlash Bay in October 2008. It was small (only 2.67 km2 in area) but significant, being the first and still the only fully protected marine reserve in Scotland.

We’ve looked at the Arran reserve in our research. Our findings, published this year in the journals Marine Biology and Marine Environmental Research indicate marine life is starting to flourish once again.

Complex seabed habitats formed by seaweeds and other plant-like creatures are recovering. These in turn act as a magnet for juvenile scallops, cod and other tasty species.

Adult scallops are benefiting too, growing in size and reproductive capacity. High levels of breeding within the reserve are likely to be seeding surrounding fishing grounds.

Marine protection is growing

Marine reserves, such as that on Arran, are the most protected form of Marine Protected Area (MPA). Due to their perceived benefits for both conservation and fisheries, the use of MPAs has grown spectacularly over the past two decades. They now cover 2.8% of the world’s oceans, and the 2010 Convention on Biological Diversity set an ambitious target for this to grow to at least 10% by 2020. Both the UK and Scottish governments are rolling out further MPAs.

There are strong arguments for the conservation value of MPAs. Clearly, if you protect ecosystems from activities which damage them, you expect benefits. Indeed, global analyses consistently find greater biodiversity and species size and abundance inside MPAs.

Certain habitats such as coral reefs and seagrass are highly sensitive to any kind of human disturbance, and protecting these areas should be a no-brainer given their ecological importance. Atlantic cod, for instance, rely on seagrass for shelter while they’re still growing.

However, the added restrictions these MPAs might put on fisheries has been met with strong resistance. In response to this lobbying pressure, it appears likely that UK governments will allow fishing to continue in the majority of the MPAs.

While low impact fisheries such as creeling and line fishing may be compatible with the conservation features in some MPAs, in many cases the most damaging types of fishing such as scallop dredging will be allowed to continue.

There are also no plans for any further highly protected MPAs, such as the one at Arran, to be established. Surely this is a wasted opportunity. Perhaps if the fishing industry could be convinced such MPAs would actually benefit fisheries, they would be met with less resistance.

Proving that highly protected MPAs benefit fisheries is difficult, but recent advances in genetics have conclusively demonstrated that disproportionately high amounts of young fish can be exported from marine reserves to neighbouring fishing grounds on tropical coral reefs.

Some scientists claim there is little evidence for them working in the cool temperate seas around the UK. But the Arran marine reserve story adds to the benefits that MPAs have provided to scallops around the Isle of Man and in Lyme Bay, and to lobsters around Lundy Island. Furthermore, recent modelling of the English Channel marine ecosystem concluded that highly protected MPAs were the best bet for both fisheries and conservation.

Crucially, the key to the success of the few MPAs in the UK to date has not just been getting the science right, but involving and getting support from the local community and fishing industries. Zoning arrangements divvying up the Clyde between fishermen and fish replenishment areas have just been proposed. This surely has to be the way forward.

Read the original article.

Publication date: 15 April 2015