Tag Archives: cold water corals

Scientists unveil first maps of deep sea corals

deep sea coralsScientists 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

Deep-sea corals live thousands of years

Gerardia coral. Credit: OAR/National Undersea Research Program (NURP) Deep-sea corals are found on hard substrates on seamounts and continental margins worldwide at depths of 300 to around 3000 m. Deep-sea coral communities are hotspots of living things, both in terms of numbers and diversity of species. They provide critical habitat for fish and invertebrates.

According to research published this week in the Proceedings of the National Academy of Sciences, newly applied radiocarbon dating of the deep water corals Gerardia and Leiopathes species show that their growth rates are extremely low, and that individual colonies live for thousands of years. The longest-lived specimens were Leiopathes species (black corals) at 4265 years old.

The coral specimens were collected with submersibles off the coast of Hawaii. The authors measured the age of the corals’ proteinaceous skeleton and found that the corals grew much more slowly than previous dating techniques had shown.

The management and conservation of deep-sea coral communities is challenged by their commercial harvest for the jewellery trade and damage caused by deep-water fishing practices.

The scientists conclude that in light of the corals’ unusual longevity, we need to better understand their ecology and relationship with other bottom-dwelling creatures before forming a coherent international conservation strategy for these important deep-sea habitat-forming species.

Black Corals
Leiopathes black corals have a dark skeleton, after which they are named. The black skeleton forms irregularly branching, tree-like structures. Gorgonian-like, the skeleton is covered with polyps. Leiopathes corals are listed on Appendix II of the Convention on International Trade in Endangered Species (CITES), which means that they are not necessarily now threatened with extinction now but that may become so unless trade is closely controlled. Gerardia species are sometimes known as False Black Corals. Not all of these are deep sea: colonies are found in the Mediterranean between 50 and 80 m.

Journal References:
E. Brendan Roark, Thomas P. Guilderson, Robert B. Dunbar, Stewart J. Fallon, and David A. Mucciarone. Extreme longevity in proteinaceous deep-sea corals. PNAS 2009 : 0810875106v1-pnas.0810875106.

E. Brendan Roark, Thomas P. Guilderson, Robert B. Dunbar and B. Lynn Ingram. Radiocarbon-based ages and growth rates of
Hawaiian deep-sea corals. MARINE ECOLOGY PROGRESS SERIES, Vol. 327: 1–14, 2006
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Countries urged to protect coldwater corals

WWF-Canada have released a new study that identifies three coldwater coral “hotspots” off Newfoundland and Labrador and assesses the impact of fishing on these fragile organisms. The study provides the scientific basis for Canadian and European governments to protect sensitive coral habitat in the Northwest Atlantic.

Coldwater corals are long-lived animals that live along continental slopes, seamounts, and mid-ocean ridges. These corals are important parts of deep-sea ecosystems and provide habitat for other invertebrates and fishes. Coldwater corals can be damaged by fishing or other seafloor directed activities and may take centuries to grow back, if at all.
Copyright WWF-Canada
“Canada, Spain, Portugal and Russia are the countries that have the greatest potential to damage these globally important concentrations of corals,” said Dr. Robert Rangeley, Vice President, Atlantic, WWF-Canada. “Their fleets are among the largest operating off Newfoundland and fish in and around the areas identified as hotspots. This also means they have the greatest opportunity to protect them.”

“Our study mapped where corals are found, and identified areas where coral bycatch is highest for a variety of fisheries and gear types,” said lead author of the study Dr. Evan Edinger. “Our research demonstrates that no matter what type of fishing gear is used, bottom-contact fishing in coral habitat damages corals. Therefore, it is very important that any areas established to protect corals exclude all bottom directed fishing activities.” This research builds on a growing global movement to protect coldwater corals and seamounts. In 2006, the United Nations General Assembly called on fisheries management agencies like the Northwest Atlantic Fisheries Organization (NAFO) to implement vulnerable habitat protection measures by December 2008. In response, last year NAFO signalled their intent to protect seamount habitats.

The Report, Coldwater Corals off Newfoundland and Labrador: Distribution and Fisheries Impacts may be downloaded at: http://wwf.ca/coral

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