Ocean science news, explainers, and statistics covering marine environments, currents, climate, coasts, seafloor research, and the changing global ocean.
An ocean dead zone is an area where dissolved oxygen falls so low that most animals cannot remain there. Scientists call the condition hypoxia, often using a threshold near 2 milligrams of oxygen per liter for coastal monitoring. Mobile fish may leave, while bottom-dwelling animals can suffocate. “Dead” is a vivid shorthand; microbes and some…
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A natural oil seep is a place where crude oil and natural gas escape from underground deposits through fractures or porous sediment and enter the sea. The flow may begin far below the seabed, rise through layers of rock and appear as bubbles, droplets, tar, or a thin slick at the surface. Unlike a sudden…
Ocean noise pollution is human-generated underwater sound that interferes with marine animals or alters the acoustic environment they depend on. Vessel engines, sonar, seismic surveys, pile driving, construction and energy operations can add steady background noise or intense pulses. Effects range from masked communication to behavioral disturbance and, at high enough exposure, hearing injury. NOAA’s…
An exclusive economic zone, or EEZ, is a sea area beyond and next to a country’s territorial sea where the coastal state has special rights to explore, use, conserve and manage natural resources. It can extend no farther than 200 nautical miles from the coastal baseline. Other states retain important freedoms, including navigation and overflight.…
