Category Archives: Atmospheric Science
ScienceDaily (May 12, 2009) — An international team of scientists has proposed a set of basic rules to help save the world’s imperiled coral reefs from ultimate destruction.
Their proposal is being unveiled at the World Ocean Conference 2009 in Manado, Indonesia, where leaders of six regional governments plus Australia and the United States are meeting to declare the largest-ever marine reserve in world history, the Coral Triangle Initiative.
“The catastrophic decline in the world’s coral reefs demands urgent management responses on two fronts,” say the researchers from the Australian Research Council’s Centre of Excellence for Coral Reef Studies (CoECRS), The Australian Museum, Woods Hole Oceanographic Institution, James Cook, Perpignan and the United Nations Universities and The Nature Conservancy.
These are the “…reduction of immediate direct threats such as climate change, over-fishing and water pollution, and actions to protect or enhance the resilience of reef ecosystems in the face of existing and unavoidable future threats,” they say.
The key to saving threatened coral ecosystems is to maintain the links (connectivity) between reefs allowing larvae to flow between them and re-stock depleted areas, the team led by Pew Fellow Dr Laurence McCook of Australia’s Great Barrier Reef Marine Park Authority (GBRMPA) argues.
“Ecological connectivity is critically important to the resilience of coral reefs and other ecosystems to which they are linked,” says Dr McCook. “The ability of reefs to recover after disturbances or resist new stresses depends critically on the supply of larvae available to reseed populations of key organisms, such as fish and corals. For reefs to survive and prosper they must in turn be linked with other healthy reefs.”
The researchers propose six ‘rules of thumb’ for keeping coral ecosystems viable, based on the results of research carried out in the Bohol Sea in the Philippines, the Great Barrier Reef in Australia, and Kimbe Bay in Papua New Guinea.
These rules are:
- allow margins of error in extent and nature of protection, as insurance against unforeseen threats;
- spread risks among areas;
- aim to create networks of protected areas which (a) protect all the main types of reef creatures, processes and connections, known and unknown; (b) achieve sufficient protection for each type of reef habitat type, and for the whole region; (c) achieve maximum protection for all reef processes (d) contain several examples of particular reef types to spread the risk;
- protect whole reefs where possible; place buffer zones around core areas.
- allow for reef species to spread over a range of distances, especially 20–30 km; and
- use a range of conservation approaches, including marine protected areas.
The rules are designed to operate in a range of situations, including where detailed scientific knowledge of local coral reefs and their species is sparse, the team says in a review article in the journal Coral Reefs.
Protecting reef connectivity and allowing reef species to freely recharge depleted areas is vital to ensuring that coral reefs remain resilient in the face of mounting human and climatic pressures. To ignore the protection of connectivity until sufficient scientific data was available on all reefs would mean allowing reefs to continue to degrade for many decades to come.
“The risks of inadequate management arising from ignoring connectivity are greater than those associated with any scientific uncertainty,” the researchers say.
The work was funded jointly by the World Bank Coral Reef Targeted Research program and the ARC Centre of Excellence for Coral Reef Studies.
“The Coral Triangle Initiative is one of the most important marine conservation measures ever undertaken anywhere in the world and the first to span several countries. It involves the six nations of Indonesia, the Philippines, Malaysia, Papua New Guinea, East Timor and the Solomon islands, and is as much about nation building and food security as it is about reef conservation” says Professor Terry Hughes, Director of the CoECRS, attending the Coral Triangle meeting today in Manado.
The ‘rules of thumb’ proposed in the research paper were an example of the sort of science being carried out across the region which will assist the Coral Triangle Initiative to achieve its goals, he said.
- L. J. McCook, G. R. Almany, M. L. Berumen, J. C. Day, A. L. Green, G. P. Jones, J. M. Leis, S. Planes, G. R. Russ, P. F. Sale and S. R. Thorrold. Management under uncertainty: guidelines for incorporating connectivity into the protection of coral reefs. Coral Reefs, (in press)
Ocean Acidification: Understanding How Mussels Have Adapted To Extremely Acidic Waters Near Underwater Volcanoes
ScienceDaily (May 1, 2009) — A student at Dalhousie University in Halifax, Nova Scotia is bringing understanding to the troubling problem of ocean acidification due to increasing atmospheric carbon dioxide.
As an undergraduate, Kim Davies worked with Dr. Verena Tunnicliffe, biology professor at the University Victoria, examining how mussels have adapted to extremely acidic waters near underwater volcanoes. The paper she co-authored will be published in the May issue of the journal Nature Geoscience.
Carbon dioxide (CO2) emitted to the atmosphere by human activities is being absorbed by the oceans, making them more acidic. Evidence indicates that emissions of carbon dioxide from human activities over the past two centuries have already led to a reduction in the average pH of surface seawater. Because acidification affects the process of calcification, the impact is severe on marine animals like corals, plankton and mollusks which have shells or plates.
So what happens to these animals over time? That’s what the researchers wanted to find out by examining vent mussels (Bathymodiolus brevior) living on the side of submarine volcanoes. The mussels, which have a calcium carbonate skeleton, are under constant stress, bathed by carbon dioxide bubbling out of the ground and from hydro-thermal vents deep beneath the surface.
And yet some of the mussels, gathered by remotely operated vehicles along the Mariano volcanic arc near Japan, were determined to be more than 40 years old and had physiologically adapted to living in their extreme environment.
The researchers discovered the mussels grew much slower than mussels in other areas and their shells were very thin. As well, the mussels’ shells were completely covered with protective protein coverings; any breach of that outer layer would quickly destroy the mussel by dissolving the underlying calcium carbonate.
“Their shells—you could see right through them,” says Ms. Davies, who did the lab analysis of samples gathered some 1,500 metres below the surface. “And yet, this species of mussels was able to adapt and build up a tolerance living close to these hydro-thermal vents as long as their protective covering was intact.”
She surmised mussels in other areas would be more vulnerable to ocean acidification because of crabs that scurry over them and wear away at their protective covering. Those predators were absent in the mussel beds near the hydro-thermal vents.
“It’s such a euphoric feeling to see that something I did as an undergrad is regarded as important science,” says Ms. Davies, a PhD student at Dalhousie whose research is now focused on the feeding ecology of the North Atlantic right whale. “Wow, it’s so great just to see your name in a high-level journal.”