caa a22 4500 465792596 CHVBK 20180323112029.0 cr unu---uuuuu 170327e19900901xx s 000 0 eng 10.2307/1351920 doi (NATIONALLICENCE)springer-10.2307/1351920 A comparison of phytoplankton assemblages and environmental relationships in three estuarine rivers of the lower Chesapeake Bay [Elektronische Daten] [Harold Marshall, Raymond Alden] A 16-month data set of phytoplankton assemblages and environmental parameters were studied in the lower James, York (-Pamunkey), and Rappahannock rivers using several exploratory statistical approaches. Based on species composition and river station relationships, three site groups were established and subsequently identified as predominantly tidal fresh, oligo-mesohaline, and mesohaline sites. Phytoplankton assemblages within these rivers were influenced and subsequently augmented by the onset of the spring freshet which was different in 1986 and 1987. Five temporal assemblages of phytoplankters were also identified and designated into seasonal groupings of spring 1986, summer-fall, summer-winter, fall-winter, and winter-spring 1987. Discriminant analysis (MANOVA) evaluations were made for water quality parameters to site and seasonal phytoplankton assemblages and these relationships are discussed. Moving downstream along an oligohaline-mesohaline gradient, the nitrogen and phosphorus levels decreased and the phytoplankton composition was more similar at several corresponding site locations in the different rivers than at stations relatively close to each other in the same river. Within these data sets approximately 58% of the explained variance was associated with site (spatial) effects, 30% with temporal effects, and 12% with site-temporal interactions. A transition from dominant bloom-producing freshwater diatoms to estuarine species occurs from the tidally influenced freshwater zone downstream. This change may be rapid as the decline ofSkeletonema potamos, or more gradual, as withCyclotella striata andCyclotella meneghiania. These are replaced downstream bySkeletonema costatum, Cyclotella caspia, andLeptocylindrus minimus as dominant species. Estuarine Research Federation, 1990 Marshall Harold Department of Biological Sciences, Old Dominion University, 23529, Norfolk, Virginia aut Alden Raymond Department of Biological Sciences, Old Dominion University, 23529, Norfolk, Virginia aut Estuaries Springer-Verlag 13/3(1990-09-01), 287-300 0160-8347 13:3<287 1990 13 12237 https://doi.org/10.2307/1351920 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.2307/1351920 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Marshall Harold Department of Biological Sciences, Old Dominion University, 23529, Norfolk, Virginia aut NATIONALLICENCE 700 1- Alden Raymond Department of Biological Sciences, Old Dominion University, 23529, Norfolk, Virginia aut NATIONALLICENCE 773 0- Estuaries Springer-Verlag 13/3(1990-09-01), 287-300 0160-8347 13:3<287 1990 13 12237 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer