A semester-long study of Great Pond and of the environmental factors that influence the lake's water quality will be presented at 2 p.m. on Monday, Dec. 7, at Colby College in Waterville. The program will be in the basement auditorium (Rm. 1) of the Olin Science Center. It is open to the public and should last about two hours.

While students found Great Pond's water acceptable, they will report that some trends in water quality measurements done revealed causes for concern for both future water quality and cold-water fisheries, according to David Firmage, the Clara C. Piper Professor of Environmental Sciences. Firmage oversees the lakes research with F. Russell Cole, Oak Professor of Biological Science.

In recent years students in the upper-level biology and environmental science course "Problems in Environmental Science" have studied all of the other lakes in the Belgrade chain, as well as China Lake and Pattee's Pond. Each year they present their findings to the public and provide a formal report to the Maine Department of Environmental Protection (D.E.P.), the lake association, and other interested parties. This year the class collaborated with the Belgrade Lakes Association to study the largest lake in the Belgrade chain.

The D.E.P. and local lake associations, in their efforts to protect and improve lake water quality, have come to depend on the students' data, D.E.P. officials said. Past research groups from Colby have recommended changes in land use within the watersheds to try to reduce the amount of phosphorus that runs off land into the lakes. Follow-up activities funded by lake associations in the past have enabled students to help implement some of the recommendations to abate phosphorus runoff. (Phosphorus that enters the lakes becomes a nutrient for algae growth, which degrades water quality.) This year 25 Colby seniors participated in the research project.