Other classes were found occasionally:
coccolithophorids, typical of marine environments, were
mainly observed at Lido, but always in very small percentages
(max 1%). Chlorophyceans and euglenophyceans,
typical freshwater forms, were found in stations
influenced by inputs from the innermost areas. The
phytoplankton populations of Palude were typically
both marine and brackish, confirming the transitional
nature of this area. During summer, S. Giuliano and
Palude had diatom blooms in both 1997 and 1998. At S.
Giuliano in June 1997, 92% of the phytoplankton was
composed of Chaetoceros cfr. compressus (21106 cell
dm3) and Cylindrotheca closterium (29106 cell
dm3), whereas, in June 1998, 70% of the total was
represented by Thalassiosira sp. (22106 cell dm3). In
Palude, in August–September 1997 and 1998, a Nitzschia
frustulum bloom was observed, with abundances
respectively of 30106 and 15106 cell