Primary production and phytoplankton dynamics in western Lake Erie.

Primary production studies have had a profound impact on the management of the Great Lakes, culminating with the Great Lakes Water Quality Agreement of 1972 between Canada and the United States. The current study examined primary production and phytoplankton dynamics in western Lake Erie with application to water quality and fisheries management practices. Annual primary production, estimated using a 14carbon tracer and both in situ and constant light incubations, ranged from 320--370 g C m-2 y-1 during the study period and was similar to the 340 g C m-2 y -1 reported in the basin for 1970. Phytoplankton standing crop, measured as chlorophyll a, declined from annual mean concentrations of 11 mg m-3 in 1970 to 4--7 mg m-3 in this study. The mean fresh-weight biomass of the phytoplankton standing crop for spring and summer ranged from 5--7 g m-3 in 1970 to current estimates of 4--5 g m-3. Taxonomic analysis of the phytoplankton community revealed the presence of more oligotrophic genera (e.g. Chlamydomonas, Cyclotella, Microcystis ) than in 1970. Summer mean carbon turnover rates, measured as a function of primary production and Chlorophyll a, have doubled from 4.5 days in 1970 to 2 days. Furthermore, upwards to 35% of the entire lake\u27s primary production would be required to support a fishery composed of top predators. It is proposed that regular measurements of primary production be integrated into both water quality and fisheries management.Dept. of Biological Sciences. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2003 .F58. Source: Masters Abstracts International, Volume: 42-02, page: 0517. Adviser: G. D. Haffner. Thesis (M.Sc.)--University of Windsor (Canada), 2003