Cook Plant preoperational studies, 1969 / John C. Ayers ... [et al.].

Zooplankton: Station MCP-16 in the intake, MCP-1 in the outfall
mouth, Station MCP-3 in the plume axis, Station MCP-8, and
Station MCP-13 at the far outer end of the plume as determined
by surface temperature.
Benthos: Stations MCP-1 through MCP-14 (MCP-15 being an air temperature station only). Our check-list system broke down, and
benthos samples in the river at the plant intake were not
obtained. While this omission was undesirable, it is not so
bad as it appears for the polluted river environment would not
be comparable to the much cleaner lake and harbor environments.
The biological data are presented in Tables 2 through 7. Phytoplankton and
zooplankton are presented in terms of organisms per liter of water, while benthos
are given in numbers per square meter of bottom surface.
Discussion of Biological Data
The phytoplankton collections (Tables 2 through 5) indicate that a total of
1,952,000 cells per liter were present at the intake and could be presumed to be
passed through the plant's condensers. Some kill-off of phytoplankters during
passage through the plant is indicated by the fact that phytoplankton numbers
in the mouth of the outfall channel (Station MCP-1) were 1,671,000 cells per
liter. Increase in cells per liter was observed at Stations MCP-3 in the plume
axis and at Station MCP-8 at the edge of the plume. Numbers at these stations
were, respectively, 4,092,000 and 2,235,000 cells per liter and included increases
in some of the normal southern Lake Michigan species of diatoms but also increases
in the numbers of the troublesome blue-green algae listed as "Oscillatoria species
(spp.)" and the yellow-brown alga "Dinobryon spp." At present we cannot tell
whether these increases were due to plant heat or to foreign water masses drifting
in from the southwest.

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