Rich cold-water coral reef in the Whittard Canyon area by the Isis ROV

Scientists have unveiled the first-ever set of maps detailing where vulnerable deep-sea habitats, including cold water coral reefs and sponge fields, are likely to be found in the North East Atlantic.

The Bristish team used complex modelling techniques to chart a surface area more than three times the size of the UK’s terrestrial boundaries. Importantly, the maps let researchers determine the proportion of coral reefs and sponge beds that would be covered by the proposed network of Marine Protected Areas (MPAs). The maps show that if all of the current proposed Marine Protected Areas are put in place, 30% of the UK’s deep sea coral reefs will be protected – but just 3% of the sponge fields.

At the World Summit on Sustainable Development in 2002 world leaders committed themselves to creating representative networks of MPAs by 2012.

Dr Kerry Howell, project lead and member of the Plymouth University Marine Institute, says the maps are important evidence with which to present to present to policy-makers. She said: “Many people think of the deep-sea as the last great wilderness on earth, but we are increasingly relying on it for food from fishing, energy from oil and gas, and now we are even mining it for precious metals like gold, copper and zinc.

Dr Howell continued: “We have better maps of the surface of Mars than some parts of our deep-sea – but this marks the dawning of a new era in deep-sea mapping, and our first steps into understanding the deep-sea realm as never before.”

Cold-water coral reefs, like their shallow water relatives, provide a source of food and shelter to many species – but unlike them, do not require light in order to grow. The UK has extensive cold-water coral reefs in its waters, and all but one are found in the deep-sea, below 200m in depth.

Deep-sea sponge fields are similarly important in the role they play in the ecosystem. They live on soft, sandy or muddy sediments at a depth of around 1,300m, in total darkness, extreme cold and under crushing pressures. Individual sponges are about the size of a tennis ball, but they live at such densities that they form a unique habitat.

Rebecca Ross, a researcher at Plymouth University who produced the maps, said “Although the mathematical process is complicated, the principle of the technique is quite straightforward: we know the conditions that we find a reef under, so we can use mathematical models to find other places that have the right combinations of conditions for reefs to grow.

“The use of predictive modelling is an important step forward in deep-sea exploration because the deep-sea is so vast and so expensive to visit that we cannot possibly hope to survey it all.”

The study is published in the scientific journal Diversity and Distributions.

What are Marine Protected Areas?

Marine protected areas describes a wide range of marine areas which have some level of restriction to protect living, non-living, cultural, and/or historic resources. The UK has signed up to international agreements such as the Convention on Biological Diversity and the OSPAR Convention, that aim to establish an ‘ecologically coherent network of Marine Protected Areas (MPAs)’ by 2012.

Further Reading

Ross, R. E. and Howell, K. L. (2012), Use of predictive habitat modelling to assess the distribution and extent of the current protection of ‘listed’ deep-sea habitats. Diversity and Distributions. doi: 10.1111/ddi.12010
So what is a representative network of MPAs?, WWF
University of Plymouth