PHYTOPLANKTON COMMUNITIES IN WATER BODIES AT DUNGENESS, UK - ANALYSISOF SEASONAL-CHANGES IN RESPONSE TO ENVIRONMENTAL-FACTORS

The major water bodies occurring on the Dungeness shingle comprise the two Open Pits, which are natural in origin, and a number of artificia l gravel pits, varying from 20 to 90 years in age. These water bodies were found to exhibit significant variations in salinity, from fresh w ater to a-oligohaline, probably for reasons of local geography. Invest igation of the phytoplankton communities of these water bodies, over a 12 month period from December 1990 to November 1991, demonstrated cle ar seasonal fluctuations in the populations of many species. It also p laced the water bodies in three discrete groups which reflected mainly variations in salinity but which also suggested that the naturalness of the Open Pits was an important factor in determining these groups.