Cold seeps

Distribution

Cold seeps were discovered in 1983 by Charles Paull and colleagues on the Florida Escarpment in the Gulf of Mexico at a depth of 3,200 meters (10,500 ft). Since then, seeps have been discovered in many other parts of the world's oceans. Most have been grouped into five biogeographic provinces: Gulf of Mexico, Atlantic, Mediterranean, East Pacific, and West Pacific, but cold seeps are also known from under the ice shelf in Antarctica, the Arctic Ocean, the North Sea, Skagerrak, Kattegat, the Gulf of California, the Red Sea, the Indian Ocean, off southern Australia, and in the inland Caspian Sea. In the Pacific Northwest, a cold seep called Pythia's Oasis was discovered in 2015. With the recent discovery of a methane seep in the Southern Ocean, cold seeps are now known in all major oceans. Cold seeps are common along continental margins in areas of high primary productivity and tectonic activity, where crustal deformation and compaction drive emissions of methane-rich fluid. Cold seeps are patchily distributed, and they occur most frequently near ocean margins from intertidal to hadal depths. In Chile, cold seeps are known from the intertidal zone, in Kattegat, the methane seeps are known as "bubbling reefs" and are typically at depths of 0–30 m (0–100 ft), and off northern California, they can be found as shallow as 35–55 m (115–180 ft). Most cold seeps are located considerably deeper, well beyond the reach of ordinary scuba diving, and the deepest seep community known is found in the Japan Trench at a depth of 7,326 m (24,035 ft).