Phytoplankton of the seasonal surveys of 1976, of September 1970, and pre- vs. post-operational comparisons at Cook Nuclear Plant / John C. Ayers.

In Table 3 the dominant and codominant forms in the stations of each
seasonal survey of 1970 through 1976 have been assembled and the numbers of
their dominant or codominant occurrences given. This is done to assist the
reader in sorting the probably important dominants and codominants from the
rare ones which might be due to the chance occurrence of a single many-celled
filament or colony.
Consideration of the dominant and codominant forms in the seasonal
surveys of preoperational 1970 through j1974 and operational 1975 and 1976
brings to light the normal variation in seasonal dominants and codominants,
rather than any effect of 1975 and 1976 operation of the plant.
The Aprils of all the years show the spring dominance of diatoms and
flagellates which is expected.
In July of 1976 the forms having more than one occurrence as dominant or
codominant (multidominants) were two diatoms, three blue-green algae, a green
alga, and flagellates. Multidominants in July 1975 were two green algae, one
blue-green, and flagellates. In the preoperational years, July 1974 had a
diatom, a blue-green, and flagellates as forms with multiple dominance
occurrences. Four diatoms and flagellates were the multidominants of July
1973. The multidominant forms of July 1972 were four diatoms, one green
alga, one blue-green, and flagellates. In July 1971 the multidominant forms
were three diatoms, two green algae, and two categories of flagellates. In
the survey of July 1970 six diatoms, a green alga, and two flagellate
categories had multiple dominance occurrences.
If there is anything of significance in this sequence of summer
dominants it is probably the pronounced drop in the frequency of dominant
diatoms between the preoperational years 1973 and 1974. The absence of
dominant diatoms in July 1975 was due to the diatom population crashing a

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