Photosynthetic Pigments as Indicators of Algal Activity in the Upper Potomac Estuary

摘要

The Potomac River was monitored at Key Bridge from May - September, 1981. Temperature, major nutrients, photosynthetic pigments, abundance of major groups of photoplankton (direct counts), and potential photosynthetic production (oxygen method) were measured weekly in surface samples collected near mid-river. Chlorophyll A showed the same general trends as the cell counts and production with greatest algal activity in late May and August and a minimum in June. Centric diatoms and chlorococcalean green algae were the major planktonic algae in 1981, as in previous years. Overall, the activity of phytoplankton did not show any significant change from previous years, and there was no evidence for prolonged nutrient depletion as a result of algal activity in the river.