Regulation of wetlands loss under Section 404 of the Clean Water Act has received high priority within the U.S. Environmental Protection Agency (EPA). Better information is needed to support regulatory decisionmaking, including information on cumulative impacts. Currently, consideration of cumulative impacts, although required by various Federal regulations, is limited. Most regulatory decisions are made on a permit-specific, site-specific basis, whereas cumulative impacts must be assessed on a broader, regional scale. Scientific information and methods necessary to support cumulative impact assessment have been lacking. An anticipatory, planning-oriented framework to complement the existing site-specific permit review program is needed; such an effort is beginning to emerge. In addition, EPA is supporting research to provide better information on cumulative effects. It is recommended that the EPA program place initial emphasis on synthesis and analysis of existing information, on maximizing its use in decisionmaking, and on information transfer. Recommended approaches include correlation of historic wetlands losses with loss of wetlands function and values, regional case studies, and development of indices of cumulative impact for use in permit review. (Copyright (c) 1988 Springer Verlag.)