Natural Nurseries

Where rivers meet oceans, the young of many species find ideal nurseries. § These transition zones between fresh and salt water are called estuaries. They are rich in river-deposited and recycled nutrients, and sea grasses provide good hiding places for the young. § Many commercially useful fish feed in estuaries when young. § Shrimps, crabs, oysters, cockles, and mussels are caught in estuaries. §
Minnow school in red-mangrove-root community, Pelican Cays, Belize
photo © Tony Rath

Treasures on Tap

One quarter of the world's oil and gas come from the sea floor, tapped by offshore drilling or deep-sea drilling. § Oceans offer other energy sources. In tropical areas, the difference in temperature between sun-warmed surface water and cold, deep water can be converted into electricity. Experimental projects are showing that Ocean Thermal Energy Conversion (OTEC) could be renewable, available round the clock, and easy on the environment. § Tidal and wave energy can also be used to generate electricity. §
Offshore oil drilling platform, Gulf of Mexico
photo © Robert W. Parvin

Recycling Stations

Oceans are the ultimate recyclers.Many compounds essential to life pass through the oceans during their own "life cycles." Water, carbon, nitrogen, phosphorus, and other compounds reside in oceans for periods ranging from minutes to millions of years. §

Water Water (including ice and vapor) moves around the earth through underground aquifers, rivers, oceans, and the atmosphere. Because it holds and transports heat, water profoundly affects climate. § And, because the water cycle is the largest movement of any substance on earth, it has great control over life on our planet. §

Carbon Carbon is life's building block--the structure for every cell of every organism on this planet. Oceans are the major reservoir for available carbon (sedimentary rocks lock in over 99 percent of the earth's carbon). Because oceans take up carbon very slowly, only about half of the carbon dioxide released by burning fossil fuels since 1800 has been absorbed into the oceans. §

Ocean Planet Exhibition Floorplan

gene carl feldman ( (301) 286-9428
Judith Gradwohl, Smithsonian Institution (Curator/Ocean Planet)