An international team led by scientists from the United States and New Zealand have observed, for the first time, the bizarre deep-sea communities living around methane seeps off New Zealand's east coast.
'This is the first time cold seeps have been viewed and sampled in the southwest Pacific, and will greatly contribute to our knowledge of these intriguing ecosystems,' says Dr Amy Baco-Taylor, from the Woods Hole Oceanographic Institution (WHOI) in Massachusetts, who co-led the voyage with Dr Ashley Rowden from New Zealand's National Institute of Water & Atmospheric Research (NIWA).
The 21-member expedition led by scientists from WHOI, NIWA, the Scripps Institution of Oceanography, and the University of Hawaii at Manoa (UH) has spent the last two weeks exploring cold water seeps and other 'chemosynthetic' ecosystems around New Zealand's east coast onboard NIWA's deepwater research vessel Tangaroa.
Cold seeps are areas of the seafloor where methane gas or hydrogen sulphide escapes from large stores deep below. Like hydrothermal vents, cold seeps support unique communities of animals living in symbiosis with microbes that can convert these energy-rich chemicals to living matter (a form of 'chemosynthesis') in the absence of sunlight.
New Zealand is one of the few places in the world where at least four types of chemosynthetic habitats occur in close proximity, allowing scientists to address key questions about the patterns of biological distribution that cannot be addressed elsewhere.
The team visited eight cold seep sites on the continental slope to the east of the North Island, lying at depths of 7501050 m.
'We discovered that one of these sites, "The Builder's Pencil", covers about 180 000 square metres (0.18 square kilometre), making it one of the largest seep sites in the world', says Dr Rowden.