Nancy Marie Foster, 59, who spent 23 years with the National Oceanic and Atmospheric Administration and since 1997 was director of its National Ocean Service in Silver Spring, died of a brain tumor June 27 at her home in Baltimore.

Dr. Foster joined NOAA's research and development office in 1977. She was with the National Marine Fisheries Service from 1986 to 1997 and left that division as deputy assistant administrator.

She had been director of the protected resources office in the late 1980s and early 1990s, and her accomplishments there included establishing NOAA's Chesapeake Bay Office in Annapolis and the Office of Habitat Conservation.

For the latter achievement, she received in 1997 what was named the Dr. Nancy Foster Award for Habitat Conservation. NOAA's Florida Keys Environmental Center in Key West was named in her honor this spring.

Dr. Foster's other honors included the Presidential Rank Award for Meritorious Service in 1999 and the Commerce Department's highest award, the Gold Medal, in 1993.

She was a native of Electra, Tex., and a graduate of Texas Woman's University. She received master's and doctoral degrees in marine biology from Texas Christian University and George Washington University, respectively.

Before going to NOAA, Dr. Foster worked at the U.S. Fish and Wildlife Service and was biology department chairman of the old Dunbarton College of the Holy Cross in Washington.

Her marriages to Jerry Cramer and Roger Cressey ended in divorce.

Survivors include her husband since May, Dr. Joseph R. Geraci of Baltimore; her mother, Evelyn Foster of Arlington; and a sister, Judy Foster of Arlington.