Metabolic sensitivities of lacustrine ecosystems to anthropogenic forcing

Present perceptions of trophic status are reviewed and considered wanting a gainst the early Thienemann-Naumann classification based on lake metabolism . This theme is developed through a consideration of the supportive capacit ies defined by the supplies of each of the main anabolic components and by the processing of fixed carbon through the water column and in the superfic ial sediments. The import of external organic carbon is acceptable within t he oxidative capacity of the aquatic system but an excess challenges its co nventional sustainability. A recent application of metabolic modelling to t he management of a lake subject to anthropogenic influences is presented.