Final Data Summary Report: Phytoplankton Monitoring in the Great Lakes: 2007-2012 Funding Years

Abstract

The Laurentian Great Lakes have a long record of adverse anthropogenic impacts on water quality and food webs. Tracking these impacts and their causes is critical so that remedial efforts can be directed where and how they are most needed. The EPA’s Great Lakes National Program Office (GLNPO) is now in its 30th year of comprehensive monitoring of the Great Lakes. Pelagic monitoring includes physical and chemical parameters, phytoplankton, zooplankton, benthic invertebrates and other measurements. These monitoring data have revealed significant changes in whole-lake conditions (e.g. Barbiero et al. 2009), thus justifying GLNPO’s mandate to track changes under the Great Lakes Water Quality Act of 1978. Specifically, phytoplankton collections provide important information on the primary food source at the bottom of the food web, and we aim to track long-term changes in the phytoplankton resulting from human influences, and so characterize causes of disturbance, their impacts, and remedial necessity. Phytoplankton are known to respond to stressors such as nutrient loading and invasive species, and ultimately integration with other program components (e.g., zooplankton, water quality) will allow the evaluation of interactions among trophic levels and provide a more holistic interpretation of causal factors in biological changes. The abbreviated objectives of the phytoplankton program are to: 1) collect phytoplankton from the Great Lakes in spring and summer excursions on board the R/V Lake Guardian; 2) identify and enumerate phytoplankton, maintaining quality assurance standards; 3) maintain and provide a database of phytoplankton data; 4) interpret phytoplankton data, including evaluation of long-term trends in phytoplankton and food web dynamics; and 5) dissemination of data and interpretations through reports, presentations and peer-reviewed journals so that results are available for aquatic management considerations. This report summarizes phytoplankton data collected under the USEPA’s Open Lake Water Quality Survey of the Great Lakes. Those unfamiliar with the project are directed to http://www.epa.gov/glnpo/monitoring/sop for a detailed background of the overall project goals, ideology and methods. Data and analyses in this report were generated by the Natural Resources Research Institute (NRRI), University of Minnesota Duluth (UMD) under the direction of Euan Reavie (Senior Research Associate -- NRRI), and this report fulfills the final task as agreed in cooperative agreement GL-00E23101-2.