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conditions. Some taxa were found at only one site while others were found at two of
three sites and not always on the same date (Appendix A: List of Taxa). Examples of
these taxa are Actinastrum hantzschii var. fluviatile, Carteria spp., Chlorogonium
elongatum, Chodatella quadriseta and C. wratislawiensis (these two were only at Site 3).
Only two taxa were found on every date at each site. These were Ankistrodesmus
falcatus var. acicularis and Scenedesmus abundans.
The only green algae at Site 1 on 9 May were five taxa (A. falcatus var.
acicularis, Cosmarium sp., S. abundans, Schroederia setigera, Tetraedron gracile) each
at a density of 10/mL (Appendix A: Numbers and Biovolumes of Individual Taxa-Site
1). At Site 2 on 9 May, A. falcatus was at 183/mL and S. abundans at 143/mL were
>100/mL. S. setigera was at 31/mL and other green algae present were not in the sample
from Site 1. At Site 3 on this date, seven
greens were at 100 or more/mL including A. hantzschii var. fluviatile (530/mL), A.
falcatus (316/mL), Carteria multifilis (112/mL), Chlorogonium elongatum (265/mL), S.
abundans (2028/mL), S. setigera (153/mL) and Tetraedron trigonum var. trigonum
(357/mL) . Besides A. falcatus and S. abundans, only S. setigera and T. trigonum were
at Site 2. The ranking of the most numerous green algae on 18 June at Site 1 was
Scenedesmus abundans (683/mL), Ankistrodesmus falcatus var. acicularis (173/mL) and
Scenedesmus denticulatus (163/mL). At Site 2, this ranking was S. abundans (316/mL),
Kirchneriella lunaris var. lunaris (194/mL), S. denticulatus (143/mL), A. falcatus
(132/mL) and Dictyosphaerium pulchellum (122/mL). At Site 3, it was S. abundans
(336/mL), A. falcatus (143/mL) and Carteria sp. (No. 1) at 102/mL. Many of the other
greens seen in the samples from sites 1 and 2 were present at Site 3, but not in densities
>100/mL. On 20 July at Site 1, the ranking was again S. abundans (367/mL) followed by
D. pulchellum and Schroederia setigera both at 173/mL. At Site 2, it was S. abundans
(224/mL) and Carteria multifilis (102/mL) and these were the only greens at 100 or
more/mL. Both D. pulchellum and S. setigera were in the sample, however. At Site 3,
four taxa were in densities of >100/mL. These were A. falcatus (214/mL), S. abundans
(153/mL), S. setigera (112/mL) and Tetraedron trigonum (122/mL). Once again, those in
highest densities at the other two sites were in the sample from Site 3 as well. On 24
August at Site 1, D. pulchellum was most numerous at 316/mL followed by A. falcatus
(194/mL), A. hantzschii var. fluviatile (153/mL), S. abundans (112/mL) and S. setigera
(102/mL). At Site 2, Chlorogonium elongatum var. elongatum (132/mL) and A.
hantzschii var. fluviatile (112/mL) were the only two greens at >100/mL. These two
were at Site 1 and those most numerous at Site 1 were at Site 2, but in lower densities
than those seen at Site 1. At Site 3, C. elongatum and D. pulchellum both at
153/mL were followed by A. hantzschii (132/mL) and again all of the taxa at the other
two sites were at Site 3 as well. None of the greens was in a density of 100/mL on 17
October at Site 1, but the three with the highest densities were S. abundans (82/mL), S.
dimorphus and Closterium acutum (each at 51/mL) and D. pulchellum (41/mL). At Site
2, five taxa were in densities of >100/mL. In rank order, these were A. falcatus and S.
abundans (both at 143/mL), S. dimorphus (122/mL) and Kirchneriella lunaris and S.
schroederia (both at 102/mL). As was the case at Site 1, none of the green algae at Site 3
was in a density of >100/mL. The ranking of the top four was A. falcatus (41/mL), S.
abundans and S. dimorphus (31/mL) and D. pulchellum (20/mL). These results
demonstrate that the distribution of taxa was similar at each site as might be expected
