( ochemical studies of the continental ma...)Extraordinary life found around deep-sea gas seeps

'The nearest known cold seep communities that have been biologically described are off Chile and Japan. The seeps off New Zealand are also remarkable in the sheer extent of their chemosynthetic communities,' says Dr Baco-Taylor.

The team pinpointed potential seep sites using sophisticated sonar to map seafloor topography and substrate and to detect plumes of methane-enriched water. The scientists then lowered a towed video and still camera system over each site to identify seep organisms and the extent of the seafloor they covered.

With the live video feed, the scientists observed 30?0 cm long tube worms emerging from beneath limestone boulders and slabs lying at the core of the seeps. Around the rocks were patches of blackened sediment and pockets of white bacterial mats. Most sites also had extensive shell beds consisting of live and dead shells of various types of clams and mussels. These were fringed with stands of another type of deep-sea tube worm that is also gutless and relies on symbiotic bacteria for its nutrition. Corals and, at two of the sites, numerous sponges, were also observed.

'We've collected samples of the animals living around the seeps for formal identification, but the distance to previously studied cold seeps implies that there are several species new to science among these new collections,' says Dr Rowden.

The team has also collected samples of the sediment and water surrounding the seeps for chemical analysis and used sonar to study the geological structures lying beneath them.

The discovery of so many sites suggests that cold seeps are very abundant along New Zealand's eastern continental margin. However
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Source:Census of Marine Life