Lake Bonney and Lake Vanda. Conservation of Antarctic freshwater environments is essential because 1) lakes and ponds are monitors of environmental change that provide clues of past and present geological changes ; 2) the simplified acquatic ecosystems of the Antarctic are excellent natural laboratories for studying ecological theory, including euthrophication, the problem of limiting nutrients, diversity, stability, and the interaction of producer and consumer tropic levels. These scientific problems are basic to the world-wide pollution problems and an understanding of these scientific problems will contribute immeasurably to the solution of pollution problems. Any future conservation policy should include not only the preservation of unique freshwater ecosystems, such as the Victoria Land dry valleys lakes, but also allowance for planned experimental manipulations of ecosystems.