Perfect storm

24 June 2015

Source: Nature Climate Change

It is often assumed that deep-sea ecosystems are shielded from the effects of climate change at the surface. On the contrary, such ecosystems are likely to be particularly sensitive to changing oceanic conditions. For one thing, many are energetically dependent on organically rich particles, which are produced in surface waters before sinking to the sea floor as 'marine snow'.

Furthermore, because many deep ecosystems have experienced relatively constant conditions for millennia, even small perturbations of the physical and chemical environment could destabilize them. Many of the species supported by these ecosystems have long life spans and generation times, meaning that their capacity to adapt quickly enough to keep pace with environmental change may be limited. So what, if anything, can be done to protect them?

This was the topic of a meeting of stakeholders held in Hobart, Tasmania, the outcomes of which are discussed by Ronald Thresher and colleagues in this issue (page 635). The focus of the workshop was the deep-sea coral communities of the Huon Commonwealth Marine Reserve, off southeast Australia. These reef systems were established before the peak of the last Ice Age, and now have protected status.

However, ocean acidification is likely to reduce the ability of taxa such as reef-building corals to calcify their skeletons. Without management intervention, these cold-water reef systems may well be seriously degraded or even lost within decades, a dire situation indeed.

For more, go to: http://www.nature.com/nclimate/journal/v5/n7/full/nclimate2713.html