The text on this site is presented as an archival version of the script of "Ocean Planet," a 1995 Smithsonian Institution traveling exhibition. The content reflects the state of knowledge at the time of the exhibition, and has not been updated.

The ozone "hole" is really a reduction in concentrations of ozone high above the earth in the stratosphere. Even normally, there's not much ozone--only 0.0001 percent of all atmospheric gases

--but it's vital because it shields us from harmful ultraviolet-B radiation§.

Each spring the amount of ozone in the stratosphere over Antarctica drops by about half, exposing the Southern Ocean to more UV-B radiation §.

Each spring the amount of ozone in the stratosphere over Antarctica drops by about half, exposing the Southern Ocean to more UV-B radiation §.

Too much could harm or kill microscopic algae and impair the ocean's ability to remove carbon dioxide from the atmosphere--contributing to climate change §.

Adlie penguins on antarctic ice floe
Like falling dominoes, each level in the antarctic food web could be affected by increased ultraviolet radiation §.
photo © José Azel/Aurora

Hazards Ahead

CFCs are ozone eaters

Rising levels of some manufactured chemicals deplete stratospheric ozone §. CFCs (chlorofluorocarbons) have been widely used as refrigerants, aerosol propellants, cleaning solvents, and foaming agents for chemicals §.

CFCs are very stable and can remain in the atmosphere for up to 150 years §.

Krill under ice
Are CFCs krill killers? Reactions set off by increased ultraviolet radiation in the Antarctic could move up the food chain, from algae to small animals that krill eat, with far- reaching results in a food web that includes 120 species of finfish, 80 species of seabirds, 6 species of seals, and 15 species of whales and dolphins--not to mention humans §.
photo © Flip Nicklin/Minden Pictures

Life Savers

International cooperation phases out CFCs

An agreement signed in Montreal, Canada, in 1987 by 47 countries established an international framework for protecting the ozone layer by phasing out the use of ozone-depleting substances. More than 75 countries have now agreed to abide by the treaty. §

Manufacturers phase in CFC alternatives

As the Montreal Protocol takes effect, alternatives less harmful to ozone, such as HFCs (hydrofluorocarbons), are replacing CFCs as coolants in automobiles and other products. §

SMUD team safely removes CFCs
The Sacramento Municipal Utilities District removes CFCs from old refrigerators, returns the coolants to the manufacturer for recycling, and sells the metal for scrap. During the program's first four years, SMUD recovered 21,000 pounds (9,500 kg) of freon, a type of CFC.
photo © James A Sugar

More Information

International Treaties Concerning the Environment and Climate Change

Ocean Planet Exhibition Floorplan

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