{"id":64811,"date":"2009-06-22T00:00:00","date_gmt":"2009-06-22T00:00:00","guid":{"rendered":"https:\/\/www.uri.edu\/news-draft\/uncategorized\/subseafloor-sediment-in-south-pacific-gyre-one-of-the-least-inhabited-places-on-earth\/"},"modified":"2009-06-22T00:00:00","modified_gmt":"2009-06-22T00:00:00","slug":"subseafloor-sediment-in-south-pacific-gyre-one-of-the-least-inhabited-places-on-earth","status":"publish","type":"post","link":"https:\/\/www.uri.edu\/news\/2009\/06\/subseafloor-sediment-in-south-pacific-gyre-one-of-the-least-inhabited-places-on-earth\/","title":{"rendered":"Subseafloor sediment in South Pacific Gyre one of the least inhabited places on Earth"},"content":{"rendered":"
\n\t\tBiomass, metabolic activity much lower than at previously explored sites<\/p>\n


\n\tNARRAGANSETT, R.I. \u2013 June 22, 2009 \u2013 An international oceanographic research expedition to the middle of the South Pacific Gyre \u2013 a site that is as far from continents as it is possible to go on Earth\u2019s surface \u2013 found so few organisms beneath the seafloor that it may be the least inhabited sediment ever explored for evidence of life.<\/p>\n


\n\tYet since half of the world\u2019s ocean is composed of similar gyres, biomass and metabolic activity may be equally low in sediment throughout much of the world.<\/p>\n


\n\tThose are among the results of a study led by 溏心vlog免费B站 oceanographer Steven D\u2019Hondt published in the online edition of the Proceedings of the National Academy of Sciences during the week of June 22. Other 溏心vlog免费B站 members of the research team were Marine Research Scientist Robert Pockalny and Oceanography Professors Arthur Spivack and David Smith.<\/p>\n


\n\t\u201cWe wanted to know what life is like in subseafloor sediment where you have the least amount of organic matter produced in the overlying water column,\u201d said D\u2019Hondt, a professor at the 溏心vlog免费B站 Graduate School of Oceanography. \u201cSo we deliberately went where no one ever goes to compare it with sites previously studied.\u201d<\/p>\n


\n\tGyres are semi-still areas in the middle of the oceans where there is little wind, little current, and very little upwelling of deep water, so the water is clear and contains few nutrients. The South Pacific Gyre is the largest of Earth\u2019s gyres, encompassing an area twice the size of North America. D\u2019Hondt describes its center as \u201cthe deadest spot in the ocean.\u201d<\/p>\n


\n\tBecause the region is so far from terrestrial sources of sediment and so few organisms live in its water, its sediment accumulates extraordinarily slowly \u2013 as few as 8 centimeters per million years.<\/p>\n


\n\tIn 2007, the international team of scientists and students collected nearly 100 cores that reached up to 8 meters below the seafloor of the South Pacific Gyre and measured the number of living cells and the amount of respiration in the sediment. Their cell counts were three to four orders of magnitude lower than have been found at similar depths outside of the gyres, and the rate of respiration was one to three orders of magnitude lower.

\n\tEqually surprising was their finding that the subseafloor community is aerobic, unlike all other previously explored sites.<\/p>\n


\n\t\u201cIn most places, oxygen is gone just a few centimeters below the seafloor, but we found that oxygen goes many meters below the seafloor at these sites, and possibly all the way through the sediment to the underlying igneous rock,\u201d D\u2019Hondt said. <\/p>\n


\n\tIn addition, D\u2019Hondt said that the burial rate of organic matter was so low in the sediment that the principle food source for the microorganisms living there may be hydrogen released by the radioactive splitting of water due to the natural decay of elements in the sediment.<\/p>\n


\n\t\u201cAs you get deeper, this hydrogen probably becomes a more important food source than buried organic matter,\u201d D\u2019Hondt said. \u201cAnd when you get deep enough, it might be the only food available. The next step in our research is to test if that is the case.\u201d<\/p>\n


\n\tThe research expedition was funded by the Ocean Drilling Program of the U.S. National Science Foundation.<\/p>\n


\nView news coverage<\/a>.
\n<\/div>\n","protected":false},"excerpt":{"rendered":"

Biomass, metabolic activity much lower than at previously explored sites NARRAGANSETT, R.I. \u2013 June 22, 2009 \u2013 An international oceanographic research expedition to the middle of the South Pacific Gyre \u2013 a site that is as far from continents as it is possible to go on Earth\u2019s surface \u2013 found so few organisms beneath […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":"","_links_to":"","_links_to_target":""},"categories":[2],"tags":[],"class_list":["post-64811","post","type-post","status-publish","format-standard","hentry","category-archives"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.uri.edu\/news\/wp-json\/wp\/v2\/posts\/64811","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.uri.edu\/news\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.uri.edu\/news\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.uri.edu\/news\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.uri.edu\/news\/wp-json\/wp\/v2\/comments?post=64811"}],"version-history":[{"count":0,"href":"https:\/\/www.uri.edu\/news\/wp-json\/wp\/v2\/posts\/64811\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.uri.edu\/news\/wp-json\/wp\/v2\/media?parent=64811"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.uri.edu\/news\/wp-json\/wp\/v2\/categories?post=64811"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.uri.edu\/news\/wp-json\/wp\/v2\/tags?post=64811"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}