Deep Blue - oases in the ocean

Eyeless spider crabs, worms with no digestive tracts or shellfish which live in close partnership with bacteria: some very strange creatures thrive around black smokers, mud volcanoes or cold water coral reefs. Dr. Michael Klages of the Alfred Wegener Institute (AWI) describes the deep-sea oases as explosions of life in a tiny area. But how do such “hot-spot” ecosystems function and what resources are hidden within them? In the EU project HERMES (Hotspot Ecosystems Research on the Margins of European Seas), biologists, geologists, physicists, oceanographers and geochemists are investigating how highly specialised communities of living organisms develop without access to warmth, light or sometimes even oxygen, and succeed in defiance of the hostile environment. HERMES is one of the most extensive programmes of European marine research, funded with 15.5 million euros and with around 50 participating institutes in 15 countries.

Under this programme, Klages, a biologist and his colleagues are studying communities of living organisms on continental slopes and so-called cold seeps, where mineral-rich water seeps from underground sources along the continental slopes. Within the framework of the International Polar Year 2007/2008, the scientists travelled on the research icebreaker Polarstern to the cold water coral reefs in the icy seas of Norway. Four young school pupils were able to join them in their research for three weeks. They were present for the first launch of the mini-submarine JAGO and the underwater vehicle QUEST, two pieces of high-tech equipment which can reach depths of 400 metres or even 4,000 metres – one manned, the other remote controlled.

As well as research and educational work, the Helmholtz scientists have taken on the task of the data management of HERMES. All data and analyses come together here, including the data from the long-term deep-sea observatory Hausgarten, off Spitzbergen. Scientists in the observatory, located in the Fram Strait between the North Atlantic and the Arctic Ocean, have been observing developments along Europe’s northern continental shelf since 1999. The network of sensors at depths between 1,000 and 5,500 metres continually measures salinity, temperature and currents and take regular sediment samples. A video camera photographs and films particular stretches of the sea bed at regular intervals. The researchers state that they are just beginning to understand the ecosystems there.

It has, however, already been established that hotspot communities are especially sensitive to local disturbances and to global climate change. The progressive warming of the northern ocean, for example, is changing life along Norway’s continental shelf. Underwater photos show that where ten years ago, many large fauna species such as shellfish, prawns or sea anemones lived, the number of some of these species has been reduced by half. Life around the gas leaks or mineral springs is also being affected by the rise in global temperatures.

No one knows how long this life in the deep can survive. Its end may be closer than we think – the loss of a valuable resource. “There is a gigantic gene pool down there. Some bacteria even survive in high concentrations of heavy metals which flow from the earth’s interior into the seawater. Those genes could be extremely useful to mankind.” For example, some of these micro-organisms might help provide environmentally-friendly purification of waste water contaminated by heavy metals. “There may be many other habitats like this anywhere in the oceans, whose existence no-one yet suspects. HERMES helps us to understand in order to protect – so we don’t destroy the underwater oases before they have been discovered and their secrets revealed”.