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

but rather a combination of: (1) increasing nutrient loading; (2) summer
epilemnetic silica depletions; and (3) a tolerant group of organisms.
Concerning the latter, Stoermer, Bowman, Kingston, and Schaedel (op. cit., p.
365) say: "The elements of the phytoplankton flora which are common to both
Lake Ontario and the upper lakes are those apparently eurytopic species such as
AsterinelLa formosa [pennate], Frag.1aa crotonenss [pennate],
Ankistrodesmus falcatus [other], Botrvococcus brauni [coccoid green],
CrvDtomonas erosa [flagellate] etc. which enjoy almost universal distribution
in both oligotrophic and eutrophic lakes." We note that the pennates
Fr^ailarija crotonensis, Tabellaria fenestrata, and 1. fenestrata v. intermedia
have been frequent dominant or codominant forms in Cook Plant collections and
consider this to be in harmony with the quotation above and with the paragraph
on page 225 of the work cited where Tbellaria fenestrata is called common,
widely distributed, and tolerant.
Centric diatoms (Figs. 8I,J,K) have varied widely in abundance during the
period of study. Abundance variations at inner and outer stations have been
directionally similar within each year but the annual patterns have been
inconsistent from year to year. The expected summer minimum did not occur in
any zone in 1977 nor in Zones 0 or 1 in 1973. Fall recoveries in abundance did
not occur in 1970, 1971, 1974, 1977, nor (except for the inner stations of Zone
2) in 1973. No clear effect of Cook Plant operation is discernable in the data
on centric diatoms.
Total algae (Figs. 8L,M,N) have, in all three depth zones and in both
inner and outer station groups, exhibited steadily rising abundances since
1974; in Zone 2 the trend in abundance has been steadily upward since 1971. In
Zone 0 mean abundance levels in 1972 and 1973 were higher than a trend line
from 1971 to 1974; in Zone 1 mean abundances in 1973 were higher than a trend

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