Unusual Brittlestar City Dominates Macquarie Ridge near Antarctica
19.05.2008 - Other
Scientists from the Census of Marine Life seamount programme, CenSeam, have surprisingly discovered millions of brittlestars living along the Macquarie Ridge, south of New Zealand. This unusual finding shows how unique and unexplored seamounts still are throughout the world's oceans.
The Macquarie Ridge is a seamount measuring 750 metres in height. Located 1,400 km south of New Zealand and extending to just north of the Antarctic Circle, it is one of the few obstacles that detours the continuous clockwise swirl of the Antarctic Circumpolar Current in the southernmost latitudes.
Although corals and sponges usually prevail around seamount peaks, scientists aboard the Research Vessel Tangaroa of New Zealand's National Institute of Water and Atmospheric Research (NIWA) found what is believed to be the first discovery of another dense aggregation of filter feeders around a seamount summit: brittlestars, which are echinoderms close to starfish, sea cucumbers and sea lilies. Scientists credit the shape of the seamount's summit and the swirling circumpolar current that flows over and around it as the reason why brittlestars can thrive around the seamount.
Scientists were surprised by their discovery. "Not only is it amazing to see a vast array of one type of organism but the implications of the find for our understanding of the relative uniqueness of seamount assemblages are potentially far-reaching," mentioned Dr. Ashley Rowden from NIWA. The eight biologists on board the Tangaroa claim that some of the species they found have never been seen in the region before, while other species are completely new to science.
