Climate shift could leave some marine species homeless

An international research team, led by Dr Mike Burrows from the Scottish Association for Marine Science, compared changing temperatures for both land and sea and from place to place over a 50 year period, from 1960 -- 2009.

The team used the data to project how quickly populations of both terrestrial and marine species would have had to relocate to keep up with the changing temperatures. They found that there was very little difference between movement rates in either environment.

Dr Burrows explains, 'When temperatures rise, plants and animals that need a cooler environment move to new regions. The land is warming about three times faster than the ocean so you might simply expect species to move three times faster on land, but that's not the case.

'If the land temperature becomes too hot for some species, they can move to higher ground where temperatures are generally cooler. That's not an option for many marine species which live at, or near, the surface of the ocean. When temperatures rise, species such as fish will be able to move into deeper water to find the cooler environments they prefer -- but other species, such as marine plants or slow-moving corals, will have to move further to find suitable habitats and could become trapped if there are no cooler places for them to go.'

Co-author Dr John Bruno, from the University of North Carolina, agrees that many marine creatures would have a hard time keeping up with climate change. He says, 'Being stuck in a warming environment can cause reductions in the growth, reproduction and survival of ecologically and economically important ocean life such as fish, corals and sea birds.'

The study also highlights the variation in ocean surface temperatures within a very small region, which also causes species movement. Spring-time temperatures in the seas around Scotland, for example, have arrived around 5 days per decade earlier on the east coast, whereas there has been almost no shift in spring temperature on the west coast.

Dr Burrows concludes, 'The areas where species would need to relocate the fastest to stay ahead of climate changes are important biodiversity hotspots, such as the coral triangle in South-eastern Asia. Our study may help conservationists to prepare for change and protect future coral habitats.'

The research was co-funded by the UK Natural Environment Research Council (NERC) and carried out as a part of the 'Towards Understanding Marine Biological Impacts of Climate Change' Working Group supported by the National Center for Ecological Analysis and Synthesis, a Center funded by the US National Science Foundation , the University of California, Santa Barbara, and the State of California.