Water science news, explainers, and statistics covering freshwater, hydrology, lakes, rivers, groundwater, ice, and Earth’s connected water systems.
A plastic bottle found on a beach may look weathered after a few years, yet its material can remain in the marine environment far longer. Sunlight makes some debris brittle. Waves grind weakened surfaces against sand and rocks, while temperature changes add stress. Weathering usually produces smaller fragments rather than a clean disappearance. The time…
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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…
The ocean carbon cycle moves carbon among the atmosphere, surface seawater, marine life, the deep ocean and seafloor sediments. Carbon dioxide crosses the air-sea boundary, reacts with seawater, enters food webs through photosynthesis and can sink in particles or travel downward with currents. Some returns quickly to the air, while some remains below for centuries…
An ocean eddy is a rotating body of seawater that separates from, forms beside, or circulates within a larger current. Eddies range from small swirls near coasts to mesoscale features hundreds of kilometers across. They can last for days to months, carrying heat, salt, nutrients, plankton and floating material as they travel. NOAA’s eddy definition…
