Phytoplankton community

Increases in nitrate + nitrite have been well documented in the Great Lakes (19). Relative increases over the past twenty years have been between 30 and 200% with the highest increases in the most populated and agriculturally productive basins of Lakes Ontario and Erie (29). Currently no adverse impacts due to this increase have been observed and concentrations are well below the 10 mg.L maximum acceptable drinking water concentration for the protection of human health. Changing N P ratios, however, can impact phytoplankton community structure (30). 

Differences in integration time scales may also affect our perception of key derived parameters such as the ThE ratio (Cochran et al. 2000). This ratio (see above) compares the POC flux derived from water column " Th profiles (and thus integrating into the past) with present primary production. As classically measured using incubation techniques, primary production is an instantaneous measurement representing the phytoplankton community as sampled at a single time. Under bloom conditions, the export of POC may lag the production of fresh organic matter and ThE ratios calculated late in a bloom may be overestimates. 

Fig. 4 Redundance analysis (RDA) on phytoplankton communities collected during the surveys of 2005-2006 and their relationship with the environmental variables, such as the Total Phosphorus (PTOT), Water Flow (WATFL), Total Suspended Solids (TSS), ammonia concentration (NH4), nitrate concentration (N03), and conductivity (COND). Acronyms were also used for phytoplankton taxa representation...

Differences in chlorophyll concentrations between present and past records in the lower part of the Ebro do not correspond with significant changes in the distribution of phytoplankton assemblages. The general trends in the distribution of phytoplankton communities appear to be consistent with those reported in previous surveys, at least in the lower part of the river. Centric diatoms such as Aulacoseira granulata, Cyclotella sp. and Stephanodiscus sp. were dominant in autumn, spring, and early summer 1989-1990, while Scenedesmus sp., Coelastrum sp., and Pediastrum sp. were most abundant in the summer of that period [7]. 

Montesanto B, Tryfon E (1999) Phytoplankton community structure in the drainage network of a Mediterranean river system (Aliakmon, Greece). Int Rev Hydrobiol 84 451 —468... 

Sanders, J.G. and S.J. Cibik. 1988. Response of Chesapeake Bay phytoplankton communities to low levels of toxic substances. Mar. Pollut. Bull. 19 439-444. 

Henry, R. and J.G. Tundisi. 1982. Evidence of limitation by molybdenum and nitrogen on the growth of the phytoplankton community of the Lobo Reservoir (Sao Paulo, Brazil). Rev. Hydrobiol. Trop. 15 201-208. 

Chlorophylls and other pigments have been frequently investigated in marine samples. As the amount of chlorophyll may be used as a marker for phytoplankton production its determination is of paramount importance in sea research [274], HPLC data have been used for the study of phytoplankton community structure [275] and for the indentification of phytoplankton groups [276], Earlier advances in HPLC pigment analysis have been reviewed [277],... 

HPLC has been further employed for the mesurement of the spatial and temporal variabilities of phytoplankton community structure [287], for the investigation of the seasonal change of algal pigments [288], for the study of the seasonal and interannual change of phytoplankton communities [289] and for the assessment of the tidal and diurnal periodicities of pigment profiles [290],... 

F1PLC has found applications in a wide variety of studies concerning the marine environment [295], It has been employed for the identification of the components of microphy-tobenthic communities [296], for the investigation of the change in phytoplankton communities [297] in many sampling sites such as the Mediterranean Sea [298], Equatorial Pacific [299], Mississipi River-influenced continental shelf [300], etc. 

R. Riegman and G.W. Kraay, Phytoplankton community structure derived from HPLC analysis of pigments in the Faroe-Shetland Channel during summer, 1999 the distribution of taxonomic groups in relation to physical/chemical condition in the photic zone. J. Plankton Res. 23 (2001) 191-206. 

Y. Obayashi, E. Tanoue, K. Suzuki, N. Handa, Y. Nojiri and C.S. Wong, Spatial and temporal variabilities of phytoplankton community structure in the Northern North Pacific as determined by phytoplankton pigments. Deep Sea Res. Part I Oceanogr. Res. Papers 48 (2001) 439 169. 

Y. Dandonneau, P.-Y. Deschamps, J.-M Nicolas, H. Loisel, J. Blanchot, Y. Montel, F. Thieuleux and G. Becu, Seasonal and interannual variability of ocean color and composition of phytoplankton communities in the North Atlantic, equatorial Pacific and South Pacific. Deep Sea Res. II 51 (2004) 303-318. 

Pigment distribution is useful for quantitative assessment of phytoplankton community composition, phytoplankton growth rate and... 

R. W., Day, K.E. and Solomon, K.R. (2001) Response of phytoplankton communities to liquid creosote in freshwater microcosms. Environ Toxicol Chem, 20, 2785-2791. 

Lignell, R., and K. Lindqvist. 1992. Effect of nutrient enrichment and temperature on intracellular partitioning of 14C02 in a summer phytoplankton community in the northern Baltic. Marine Ecology Progress Series 86 273-281. 

Auclair, J. C. 1995. Implications of increased UV-B induced photoreduction Iron(II) enrichment stimulated picocyanobacterial growth and the microbial food web in clear-water acidic Canadian Shield lakes. Canadian Journal of Fisheries and Aquatic Sciences 52 1782—1788. Auclair, J. C., P. Brassard, and P. Couture. 1985. Total dissolved phosphorus Effects of two molecular weight fractions on phosphorus cycling in natural phytoplankton communities. Water Research 19 1447—1453. 

Legendre L. and Krapivin V.F. (1992). Model for vertical structure of phytoplankton community in Arctic regions. Proc. of 7th Int. Symp. on Okhotsk Sea Sea Ice (February 2-5, 1992, Mombetsu, Japan). Okhotsk Sea Cold Ocean Res. Assoc., Mombetsu, pp. 314-316. 

Piazena, H. and Hader, D. P., Penetration of solar UV irradiation in coastal lagoons of the southern Baltic Sea and its effect on phytoplankton communities, Photochem. Photobiol., 60, 463, 1994. 

Berard A, Pelte T, Druart J-C. 1999. Seasonal variations in the sensitivity of Lake Geneva phytoplankton community structure to atrazine. Archiv fuer Hydrobiologie 145 277-295. 

Kasai F, Hanazato T. 1995b. Genetic changes in phytoplankton communities exposed to the herbicide simetryn in outdoor experimental ponds. Arch Environ Contam Toxicol 28 154-160. 

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