Abstract

Bay of Quinte is one of the few intensely studied ecosystems in the Great Lakes. Although it has long term data sets (>30 years), little was known about its microbial food web until Fisheries & Oceans launched an investigation in 2000. Samples were collected at two of the long term stations, an upper bay station (Belleville – average depth <5 m) and a lower bay station (Conway – average depth 30m) on biweekly cruises from May to October. Microbial loop parameters: bacteria, picoplankton, and heterotrophic nanoflagellates, ciliates were enumerated with standard techniques and biomass was converted to carbon units. Phytoplankton and Zooplankton data were used to create a planktonic carbon budget. Unexpectedly, heterotrophic nanoflagellates are an extremely large portion of the planktonic foodweb at both stations contributing 30-60% of the carbon at Belleville and 44- 75% at Conway. Phytoplankton contributed 30-46% at Belleville and 16-48% at Conway. Size fractionated primary production was also estimated by ¹⁴C technique at various light intensities in an incubator. Bacterial growth experiments were conducted using a leucine incorporation technique in later years. These data will be discussed in detail.