Limpets on the move as sea temperatures warm up

Marine species, such as the common tortoiseshell limpet, the acorn barnacle and the toothed topshell, are moving home in the wake of rising sea temperatures because of climate change, according to a four-year study.

The MarClim Project, which mapped the distribution of 57 species at more than 400 locations across the UK, found many marine species are responding to climate change by migrating to cooler parts of the coast - and they seem to be moving more quickly and further than their terrestrial counterparts.

Nova Mieszkowska from the Marine Biological Association said the study to investigate the effects of climate change on marine biodiversity compared data from the 1950s with new studies of the same sites.

"We usually hear about climate change in terms of air temperatures increasing and its effects on land. But, although we know much less about it, climate change also happens at sea," Dr Mieszkowska said.

Larissa Naylor, a Senior Scientist at the Environment Agency, said the coastline of the British Isles was rich in habitats, such as rock pools and mud flats, and was home to a variety of creatures - creatures that were important indicators of marine health and essential elements of the food chain.

"One way of testing the response of marine biodiversity to climate change is to track the range and abundance of these creatures, like limpets, snails, barnacles and seaweed, on the shore between high and low tide," Dr Naylor said.

"We've seen many of these species moving from the areas they are normally found - mainly due to rising sea surface temperatures. The creatures are moving to find more suitable homes in new locations as warmer waters have allowed some species to extend their range northwards. It also shows marine species can more readily extend their distribution ranges in order to survive the unavoidable impacts of climate change, when compared with terrestrial counterparts."

Overall, the project found since the mid 1980s, the southern, warm water species have been moving north into the colder North Atlantic and North Sea and east in the English Channel, and northern species are retracting from their southern distribution limits.

The key movers include:

the purple acorn barnacle, which has extended its distribution range 170kms east from the Isle of Wight to Kent
the largest seashore snail, the toothed topshell, which has increased its range 45kms east along southern England from Lyme Regis to east of Weymouth
another southern snail, the purple topshell, which has spread 85km further along the coast of north Scotland over the last 20 years
a northern brown seaweed known as dabberlocks, which has disappeared from much of south west England, while a southern brown seaweed called Bifurcaria bifurcata has extended 150kms from Devon to Portland Bill in Dorset
the common tortoiseshell limpet, which has retracted from much of the Irish Sea, including the Isle of Man, and has only been seen in north Scotland in recent years.
Dr Mieszkowska said the next research programme, IndiRock, would build on these findings and focus on the effects of climate change on marine communities and ecosystems as a whole, not just individual species. The links between changes in intertidal ecosystems and those offshore, such as plankton and fish, would also be investigated.

"IndiRock will also track invasive species around the British coastline and survey the French coast of the English Channel to ascertain what warm water species have the potential to invade from the continent, and where and when it could occur," she said.

The MarClim project's findings support a Government report card published last month that highlighted the impact of climate change on the marine environment.

The MarClim project was led by the Marine Biological Association. It was funded as a partnership under the umbrella of the UK Climate Impacts Programme (UKCIP) by the Environment Agency, English Nature, Defra, Scottish Natural Heritage, Scottish Exec, Joint Nature Conservation Committee, Countryside Council for Wales, Crown Estate, States of Jersey and WWF. The Plymouth Marine Laboratory, University of Plymouth, Scottish Association for Marine Science and University College Cork were research partners.

IndiRock will be carried out by a team of researchers led by Prof S.J. Hawkins and Dr N. Mieszkowska at the Marine Biological Association and Dr M.T. Burrows at the Scottish Association for Marine Science. Funding is currently being secured for IndiRock and specific details are still to be finalised with sponsors.