Australia’s highly endemic deep-water coral communities are under a current and accelerating threat of being squeezed out of existence, between seamount summits typically deeper than 1000 m. and carbonate levels that are falling and pushing the saturation horizon towards the surface. This horizon, below which the reef-forming corals apparently cannot grow (Guinotte et al., Front. Ecol. Env. Sci., 2006), has already shoaled by 50-130 m in the last 200 years due to industrial CO2 emissions (Thresher, et al., ms). Under-saturated water is likely already encroaching on the reef, which recent surveys found is just below the current saturation horizon (Thresher, et al., ms), and not above it, as expected. There is real risk that the reef is already stressed and may even be dying. The problem will only get worse. Under a “business-as-usual” scenario, even the tops of the seamounts will be under-saturated in the next 50-100 years. With nowhere to go, Australia’s cold-water reefs could “simply disappear” (Poloczanka, el al., Ann. Rev. Oceanog. Mar. Biol., 2007).
There are presently no adaptation strategies for dealing with this threat, nor even any research on strategies, even though it challenges the key objectives of the SE Commonwealth Marine Reserve Network, and the survival of deep-sea reefs globally. This project, developed in consultation with DEWHA, will evaluate the magnitude of the threat to Australia’s key reef-forming species, and identify and test management options for adapting to it. It addresses NARP priorities for determining ecosystem vulnerability and the feasibility of intervention and adaptation strategies.