Gary has authored more than 120 articles in professional journals, books, and technical reports on such diverse topics as marine protected areas, spiny lobster and abalone fisheries, sea turtle conservation, coral reef dynamics, kelp forest ecology, and ecological monitoring. In 1996, he co-edited a book on the role of science in national park management. He has guided development of a sustained ecological monitoring program for the United States National Park System, and helped more than a dozen national parks design comprehensive, site-specific, monitoring programs.
He is recognized by the American Fisheries Society as a Certified Fisheries Biologist, and he was elected a Fellow of the American Institute of Fishery Research Biologists in 1985. He has led several profession organizations, in such positions as President of the American Academy of Underwater Sciences, President of the George Wright Society, Member of the Board of Directors of the Natural Areas Association, and District Director of the American Institute of Fishery Research Biologists. He has received several professional awards, including United States Department of the Interior Honor Awards for his contributions as a TEKTITE I Aquanaut in 1969 and for his research on ecological monitoring in 1986. He was also recognized in 1993 by the U. S. Secretary of the Interior for his contributions to establishment of the National Biological Survey.