Population, phytoplankton

Comparison with other Studies. How do the results of our investigation compare with similar studies Our results corroborate the data provided in a similar study of the effect of UV-B on primary productivity in the southeastern Pacific Ocean (35). In the latter study, it was noted that enhanced UV-B radiation caused significant decreases in the productivity of surface and deep samples. Compared to ambient, primary productivity decreased with increasing doses of UV-B. In another study in which in situ experiments using natural Antarctic phytoplankton populations, it was noted that incident solar radiation significantly depressed photosynthetic rates in the upper 10-15 meters of the water column (36). It was also found that the spectral region between 305 and 350 nm was responsible for approximately 75 percent of the overall inhibitory effect. 

Foodwebs of the Delta have been altered in many ways through the multiple changes that have occurred within the Delta in recent decades. For example, the turbidity and organic matter supply to the Delta have been generally decreasing due to land use changes and upstream reservoirs. Phytoplankton populations also have... 

Kobbia, I.A. 1982. Response of phytoplankton populations in some Egyptian irrigation drains to the aquatic weed herbicide acrolein. Egypt. Jour. Botany 25 41-67. 

One of the most important groups of all living matter is marine phytoplankton. Natural oceanic phytoplankton populations vary in 8 C-value by about 15%c (Sackett et al. 1973 Wong and Sackett 1978). Rau et al. (1982) demonstrated that different latitudinal trends in the carbon isotope composition of plankton exist between the northern and the southern oceans south of the equator the correlation between latitude and plankton C-content is significant, whereas a much weaker relationship exists in the northern oceans. 

Pichard, S. L. Paul, J. H. (1991). Detection of gene expression in genetically engineered microorganisms and natural phytoplankton populations in the marine environment by mRNA analysis. Applied and Environmental Microbiology, 57, 1721-7. 

Furnas, M.3., 1982. The dynamics of summer phytoplankton populations in Narragansett Bay. Ph. D. Thesis, University of Rhode Island, Kingston, RI. 

Hama, T. 1988. 13C-GC-MS analysis of photosynthetic products of the phytoplankton population in the regional upwelling area around the Izu Islands, Japan. Deep Sea Research 35 91-110. 

Hama, T., and N. Handa. 1987. Pattern of organic matter production by natural phytoplankton population in a eutrophic lake. 2. Extracellular products. Archiv fur Hydrobiologie 109 227-243. 

Hama, T., and T. Honjo. 1987. Phytoplankton products and nutrient availability in phytoplankton population from Gokasho Bay, Japan. Journal of Experimental Marine Biology and Ecology 112 251-266. 

Wolter, K. 1982. Bacterial incorporation of organic substances released by natural phytoplankton populations. Marine Ecology Progress Series 7 287-295. 

Hama J, Handa N (1992) Diel variation of water-extract-able carbohydrate composition of natural phytoplankton populations in Kinu-ura Bay. J Exp Mar Biol Ecol 162 159-176... 

Van Oijen T, Van Leeuwe MA, Granum E, Weissing FJ, Bellerby RGJ, Gieskes WWC, De Baar HJW (2004b) Light rather than iron controls photosynthate production and allocation in Southern Ocean phytoplankton populations during austral autumn. J Plankt Res 26 885-900... 

Price NM, Ahner BA, Morel FMM (1994) The equatorial Pacific ocean grazer controlled phytoplankton populations in an iron-limited ecosystem. Limnol Oceanogr 39 520-534... 

Brussaard CP, Marie D, Bratbak G (2000) Flow cytometric detection of viruses. J Virol Methods 85 175-182 Brussaard CPD (2004) Viral Control of Phytoplankton Populations - a Review. JEukaryot Microbiol 51 125— 138... 

Use of solute speciation models to help predict metal availability to organisms in natural systems has not been attempted to date. Statistical comparisons of calculated Cu activities in various natural waters with concentrations of Cu in resident phytoplankton populations would provide a relatively simple test of the laboratory-based models of Cu availability. For organisms other than phytoplankton, however, the problem of modeling the bioavailability of metals in natural systems will be more complex. 

In the Central North Pacific Ocean (CNPO) it has also been reported that phosphorus availabiHty limits N2 fixation and primary production (Karl et al, 2001 a,b) (but iron availability may also play a role as suggested by Wu et al (2000). Karl et al (2001a,b) contend that since the mid 1970s there has been an enhanced stratification in the CNPO and a decreased inorganic nutrient avadabihty which selects for diazotrophs and shifts from a N-hmited phytoplankton population to one that is either P or Fe Hmited (see Karl et al. Chapter 16, this volume). 

DuRand, M., Olson, R., and Chisholm, S. W. (2001). Phytoplankton population dynamics at the Bermuda Atlantic Time-series station in the Sargasso Sea. Deep Sea Res. II48, 1983—2004. 

Macisaac, J. (1978). Diel cycles of inorganic nitrogen uptake in a namral phytoplankton population dominated by Gonyaulax polyedra. Dmnol. Oceanogr. 23, 1—9. 

Probyn, T. A. (1985). Nitrogen uptake by size fractionated phytoplankton populations in the southern Benguela upweUing system. Mar. Ecol. Prog. Ser. 22, 249—258. 

Savidge, G., and Johnston, J. P. (1987). Urea degradation rates by size-fractionated phytoplankton populations in a temperate estuary. Estuar. Coast. Shelf Sci. 24, 433M-47. 

Brussaard, C. P. D. (2004). Viral control of phytoplankton populations—A review. J. Eukaryotic... 

Harrison, P., and Turpin, D. (1982). The manipulation of physical, chemical, and biological factors to select species from natural phytoplankton populations. In Marine Mesocosms Biological and Chemical Research in Experimental Ecosystems (Grice, G., and Reeve, M., eds.). Springer, New York. pp. 275-287. 

Stoke, W., McCoUin, T., Noordeloos, A., and Riegman, R. (1994). Effects of nitrogen source on the size distribution within marine phytoplankton populations. J. Exp. Mar. Biol. Ecol. 184, 83—97. 

Harrison, W. G., Platt, T. (1986). Photosynthesis-irradiance relationships in polar and temperate phytoplankton populations. Polar Biol 5, 153-164. 

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