Washington - Francis "Chris" Christy, a respected authority on international fish conservation and a deft fly fisherman, died June 19 in his home in Washington. He had chronic obstructive pulmonary disease. He was 82.

In 1965, Christy co-wrote a book that described some of the earliest warnings on the dangers of commercial overfishing. "The Common Wealth in Ocean Fisheries: Some Problems of Growth and Economic Allocation" suggested the possibility that entire populations and habitats could be devastated by overfishing, which in turn could cause the world industry to collapse.

Christy worked as a fisheries management expert and economist for the U.N. Food and Agriculture Organization from 1980 to 1989 in Rome. In that position, he advised developing countries such as Malaysia and the Republic of Maldives on building a successful fishing industry that would boost their economy but not hurt the overall fish population.

He did this by applying basic economic principles to the idea that oceans have a limited supply of fish and that countries have unlimited demand for them. He helped governments install greater commercial oversight to keep both the fishing industry and the fish population healthy.

Christy's research and publications on international fisheries management and ocean conservation played a major role in the 1982 U.N. Law of the Sea treaty. His work helped outline the guidelines and definitions for nations' rights and responsibilities for use of the world's oceans.

Francis Taggart Christy Jr. was born in Brooklyn, N.Y., in 1926. After two years serving in the Navy during World War II, he graduated from Yale University in 1949 with an English degree. He then enrolled in the University of Michigan natural resources conservation graduate program and received his master's degree in 1953 and doctorate in 1964.

Christy moved to the Washington area in the early 1950s to work as a researcher at Resources for the Future, an early environmental think tank created by funding from the Ford Foundation. During the 1960s, he was vice president for conservation at the Audubon Naturalist Society.

Christy joined the U.N. Food and Agriculture Organization in 1980. He retired in 1989 but continued working there and at other organizations such as the World Bank and Inter-American Development Bank as a part-time researcher for the rest of his life.

In his spare time, Christy enjoyed photography and exhibited his work in several local juried competitions. Christy also was an avid angler known for his ability to float serenely in his canoe while casting a perfect arcing 35-foot line, wet or dry fly. He owned a fishing cabin in East New Market, Md., took trips to the Bahamas for bonefish and made a yearly pilgrimage to Croatia's Gacka River to fish its famous trout.

His marriage to Priscilla Meek ended in divorce.

Survivors include his wife of 25 years, Barbara Cleveland, of Washington; three children from his first marriage, Catherine Christy of Louisville, Colo., Susannah Christy of Haiku, Hawaii, and Sam Christy of Cambridge, Mass.; a brother; and four grandchildren.