Carbon Cycle

The carbon cycle describes the exchange of carbon among Earth’s biosphere (life), atmosphere (air), hydrosphere (water), pedosphere (soil) and lithosphere (rocks, crust, and mantle). It is one of several biogeochemical cycles on Earth that play a key role in making life possible and in regulating many planetary systems.

Exchanges between these spheres take many forms. Atmospheric carbon dioxide can readily dissolve into surface waters, and both atmospheric and carbon dioxide dissolved in the ocean are easily and frequently taken up living organisms. Transfer of carbon into the lithosphere takes much longer. Carbon in the lithosphere is also less mobile, often remaining stored there for millions of years, but large amounts can be released in an instant during a volcanic eruption. Human use of fossil fuels and other activities is also releasing an increasing amount stored in hydrocarbons back to the atmosphere as carbon dioxide.

Some organisms—such as photosynthetic plants and microbes and chemosynthetic bacteria—are able to take inorganic carbon, primarily in the form of carbon dioxide, and combine it with water to form simple carbohydrates (sugars). These carbohydrates formed by photosynthesis or chemosynthesis serve as the basic building blocks of all organic (carbon-containing) molecules that are necessary for life. Carbon dioxide dissolved in water is likewise readily incorporated into the marine food chain and into the carbonate minerals that make up the shells or skeletons of many marine organisms.

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From Oceanus Magazine

Chasing Ocean ‘Snowflakes’

Scientists envision putting a flotilla of devices in the ocean to act as “eyes” that can track the “marine snow” that drifts down into the ocean.

The Living Breathing Ocean

Rainforests have been dubbed the Earth’s lung, but like us, our planet has two lungs. The second one is the ocean.

Marshes, Mosquitoes, and Sea Level Rise

In the 1930s, the Cape Cod Mosquito Control Project dug approximately 1,500 miles of ditches across marshes on the Cape to drain their water and reduce the number of ponds where mosquitoes can breed. Woods Hole Oceanographic Institution biogeochemist Amanda Spivak is studying how this and other management decisions have changed the ability of coastal marshes to store carbon and protect against sea level rise.

The Discovery of Hydrothermal Vents

In 1977, WHOI scientists made a discovery that revolutionized our understanding of how and where life could exist on Earth and other planetary bodies.

Mission to the Ocean Twilight Zone

The twilight zone is a part of the ocean 660 to 3,300 feet below the surface, where little sunlight can reach. It is deep and dark and cold, and the pressures there are enormous. Despite these challenging conditions, the twilight zone teems with life that helps support the ocean’s food web and is intertwined with Earth’s climate. Some countries are gearing up to exploit twilight zone fisheries, with unknown impacts for marine ecosystems and global climate. Scientists and engineers at Woods Hole Oceanographic Institution are poised to explore and investigate this hidden frontier.


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News Releases


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WHOI in the News