Phytoplankton of the seasonal surveys of 1977, and further pre- vs. post-operational comparisons at Cook Nuclear Plant / John C. Ayers, Susan J. Wiley.

and outer station groups and in all three depth zones. The increasing
diversities are attributed to the eutrophication of the lake; there is no
evidence from this study that plant operation has adversely affected (lowered
the diversity of) the phytoplankton community, instead the community has in
the operational years continued to be more diverse than it was in the
preoperational years.
Values of phytoplankton redundancy for collections during the seasonal
surveys of 1970 through 1977 have been calculated. Plots of mean
redundancies against time show visual evidence of a trend, beginning in 1973,
for redundancies to become somewhat lower. If real, the trend would indicate
a tendency for the species in the community to become more equal in numbers
of individuals. Rising redundancies (one or a few species dominating the
community) would be an adverse effect.
Parallelism between the curves for redundancies at inner and outer
station groups has, since 1972, been much better than in 1970 and 1971. This
indication that changes in redundancy in the two station groups are now more
alike than in the earliest years is taken to mean some change in the lake,
not any effect of Cook Plant operation.

90