Indicator Approaches Used in the Great Lakes International Surveillance Program

The traditional emphasis on water chemistry (conventional pollutants and algal nutrients) in the joint U.S. and Canadian Great Lakes International Surveillance Plan (GLISP) has recently been expanded to include toxic substances and an ecosystem, basin-wide approach which encompasses the monitoring of atmospheric deposition, habitat and biota. Indicators in the plankton and benthos continue to be of value in tracking eutrophication trends. However, toxic substances problems in the Great Lakes have prompted a new integrated approach to monitoring, one which uses pollutant sources evaluation and specific tests on pollutant fate and distribution in water and sediment and on biotic effects. The overall goals of restoration and enhancement of water quality and habitat have prompted the development of new ecosystem objectives for the Great Lakes, using native fish species as indicators and integrators of ecosystem health.