Exciting discovery made on the South Pacific Ocean's Macquarie Ridge

During their month long research trip to the Macquarie Ridge recently, scientists aboard the Research Vessel Tangaroa of New Zealand’s National Institute of Water & Atmospheric Research (NIWA), discovered an seemingly unlikely colony of starfish-like echinoderms called brittlestars living at the summit of a huge seamount. These critters take advantage of the dramatic 4km/hr ocean current of the dramatic 4km/hr ocean current at the summit, capturing prey as it is blown over the seamount. According to Dr. Mike Willams of NIWA, “This current is estimated to be 110 to 150 times larger than all the water flowing in all the rivers of the world.”

The Macquarie Ridge extends southwest of New Zealand and then curves southeast before ending at around 58 degrees south. Running along the Macquarie Fault Zone, a major right lateral-moving transform fault along the seafloor of the south Pacific Ocean, and also the tectonic plate boundary between the Indo-Australian Plate to the northwest and the Pacific Plate to the southeast the ridge is the result of the two abutting plates. Macquarie Island, along the ridge, was formed from the thrusting of the two plates. It does not have large-scale sediment, was not formed by a volcano and does not have suffered from glacial activities. The age of the rocks forming the island is extremely young geologically and there is much interest from scientists and geologists to study the island, the ridge, the trenches alongside it, and the life it supports.

Very few of the 100,000 seamounts which rise higher than 1km above the sea have been explored. It was originally thought that only corals and sponges covered the seamounts, so the discovery of the brittle stars was an exciting and significant find.

The Census of Marine Life seamount programme, CenSeam, hosted the trip. The voyage was largely funded by the New Zealand Foundation for Research, Science and Technology.

Sources
www.survivalmachine.org

http://censeam.niwa.co.nz
This ten year old organizations, mission is “to determine the role of seamounts in the biogeography, biodiversity, productivity, and evolution of marine organisms, and to evaluate the effects of human exploitation on seamounts.” A detailed account of the Tangaroa is on the site, along with similar expeditions and their outcomes. Very interesting reading, about the trips,t he people, and life on board.