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You will need Adobe Acrobat Reader to view the files on this page. See EPA's PDF page to learn more about PDF and for a link to the free Acrobat Reader. Zooplankton Annual Report
The
Laurentian Great Lakes constitute the largest continuous body of fresh
water on earth, and with a volume of 24,620 km2 (Wetzel, 1983),
contain nearly 20% of the world’s unfrozen fresh water.
These lakes represent an enormous cultural and economic resource
for both the United States and Canada.
Increasing population and industrial growth in recent history,
however, has produced a trend of increasing eutrophication and raised
concerns about declining water quality in the lakes.
As a result of these concerns, in 1972 the United States and Canada
signed the Great Lakes Water Quality Agreement as an expression of each
country’s commitment to restore and maintain the chemical, physical and
biological integrity of the Great Lakes Basin Ecosystem. GLNPO's monitoring of the Great Lakes began in 1983, with coverage at that time including Lakes Michigan, Huron and Erie. Initially Lakes Ontario and Superior were excluded from monitoring because the former was already monitored annually by Canada, and the latter was not felt to be susceptible to eutrophication. In 1986 sampling was extended to include Lake Ontario, and in 1992 sampling of Lake Superior was added. In addition to a wide range of physical and chemical parameters, the lakes have been sampled for phytoplankton and zooplankton, including crustaceans and rotifers, since the inception of the program. In 1997, a benthic invertebrate biomonitoring program was added to complement the existing open water surveillance sampling. This sampling program is unique in that all five lakes are sampled by one agency, and samples are analyzed by one primary lab. Consequently, analytical methods, and most importantly taxonomy, remain consistent both over time and across all five lakes. In this report we will present, for the first time, results of GLNPO's biological surveillance sampling program from all five Laurentian Great Lakes. Our goal here is to provide a brief general description of the offshore planktonic and the benthic communities of all five Great Lakes from GLNPO's 1998 surveys. Questions regarding this report should be directed to: |
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