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 750–1050 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.
A few cold seep sites were previously known along the New Zealand coast from geological and biogeochemical studies of the continental margin. But this is the first time the biodiversity of the animal communities living at these sites has been observed directly and thoroughly documented, providing the first discovery of cold seep communities in the entire southwest Pacific.
'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 30–40 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, this expedition also revealed the extent to which these communities may face serious threats from human activities. At all of the seep sites, there was evidence of fishing damage in the form of trawl marks, lost fishing gear, and extensive areas of deep-sea coral rubble.
Dr. Fiona Proffitt | EurekAlert!
Species may appear deceptively resilient to climate change
24.11.2017 | University of California - Davis
Scientists team up on study to save endangered African penguins
16.11.2017 | Florida Atlantic University
High-precision measurement of the g-factor eleven times more precise than before / Results indicate a strong similarity between protons and antiprotons
The magnetic moment of an individual proton is inconceivably small, but can still be quantified. The basis for undertaking this measurement was laid over ten...
Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...
The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.
Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
24.11.2017 | Physics and Astronomy
24.11.2017 | Health and Medicine
24.11.2017 | Earth Sciences