During the summers of 2000, 2001 and 2002, the littoral zone of Conesus Lake (40°54'N, 77°43'W) supported massive blooms of metaphyton, mostly filamentous green algae (Zygnema sp. and Spirogyra sp.). Extensive agricultural activity (60–80% of the land use) within the lake’s western subwatersheds is responsible for the loading of large quantities of nitrate (up to 1800 g/ha/day) and total phosphorus (up to 34 g/ha/day) into the lake during precipitation events (MAKAREWICZ et al. 2001). Large assemblages of M. spicatum and accompanying metaphyton growth were often located near stream mouths (Fig. 1) and a significant correlation existed between stream nutrient loading (total phosphorus, soluble reactive phosphorus and nitrate nitrogen) during precipitation events and the standing crop of macrophytes (Fig. 2). To further evaluate the relationship between stream nutrient loading and growth of metaphyton, the hypothesis that stream effluent high in dissolved phosphorus and nitrate had a stimulatory effect on Conesus Lake metaphyton biomass was tested in situ in continuous flow incubation chambers.
Posted with permission of publishers: E.Schweizerbart'sche Verlagsbuchhandlung OHG (Naegele u. Obermiller) Science Publishers Johannesstr. 3A
Makarewicz, J (2006). The impact of stream nutrient loading on macrophytes and metaphyton in Conesus Lake, USA. Verh. Internat. Verein. Limnol; 29: 1-4.