Phytoplankton, uptake

Dachs J, Eisenreich SJ, Baker JE, Ko FC, Jeremiason JD (1999) Coupling of phytoplankton uptake and airwater exchange of persistent organic pollutants. Environ Sci Technol 33 3653-3660 Dachs J, Lohmann R, Ockenden WA, Mejanelle L, Eisenreich S, Jones KC (2002) Oceanic bio-geochemical controls on global dynamics of persistent organic pollutants. Environ Sci Technol 36 4229 1237... 

Thus, with a variable degree of empiricity, mass transfer coefficients for a number of biologically relevant cases have been described phytoplankton uptake [60], periphyton uptake [61], coral-reef supply of nutrients [62-64], fixation of carbon at leaf surfaces [65], etc. 

Sunda, W. G. and Huntsman, S. A. (1995). Regulation of copper concentration in the oceanic nutricline by phytoplankton uptake and regeneration cycles, Limnol. Oceanogr., 40, 132-137. 

A significant fraction of DON is mineralized through the microbial food web, and becomes available for phytoplankton uptake. 

These stable DIP concentrations are believed to be controlled by a buffering of DIP through the adsorption and desorption onto metal oxide surfaces. This P buffering is believed to balance the low availability of SRP in higher-salinity waters, which occurs from phytoplankton uptake and anionic competition for surface adsorption sites. 

Horrigan, S. G., and McCarthy, J. J. (1982). Phytoplankton uptake of ammonium and urea during growth on oxidized forms of nitrogen. J. Plankton Res. 4, 379-389. 

Most of the water masses in the Baltic Sea are found above the halocline, e.g., in the Baltic Proper only 20% of the volume is below the halocline. Deep-water entrainment and especially internal nutrient turnover processes (phytoplankton uptake, N2 fixation, sedimentation, denitrification) have a profound influence on concentrations in surface water. Decreases in nutrient concentrations in surface waters of the Baltic Sea have been interpreted as consequences of reduced external loading. However, the total amount of N and P in the water mass and active... 

J. (1999a) Coupling of phytoplankton uptake and air-water exchange of persistent organic pollutants. Environ. Set Technol. 33, 3653-3660. 

The differences between prokaryotic and eukaryotic phytoplanktonic uptake of iron must affect competition and hence the composition of primary producer communities (Hutchins et al. 1999). The rate of transport of iron into cells depends upon the number of receptors on the membrane surface, so low iron concentrations favour growth of the pi-coplankton, which have a large surface area to volume ratio. 

Figure 6 Plots of filterable zinc and cobalt concentrations vs. phosphate at two stations in the subarctic Pacific (Station T-5, 39.6° N, 140.8° Wand Station T-6, 45.0° N, 142.9° W, Aug. 1987). The decrease in zinc with decreasing phosphate is caused by the simultaneous removal of both metals via cellular uptake and assimilation by phytoplankton. Cobalt becomes depleted by phytoplankton uptake only after zinc concentrations drop to very low levels <0.2nmol kg ). This pattern is consistent with metabolic replacement of cobalt for zinc, as observed in phytoplankton cultures (see Figure 5). Data plots after Sunda WG and Huntsman SA (1995) Cobalt and zinc interreplacement in marine phytoplankton Biological and geochemical implications. Limnology and Oceanography 40 1404-1417.

B. Different outflow rates from the catchment. Default value is 0.0025 D. Different sedimentation rates. Default value is 0.3 F. Different phytoplankton uptake rates. Default value is 1... 

Fig. 9.8. A. Model simulation for Cs. The driving function is an atmospheric fallout during month 24, with a peak value of 25 kBq/m. Curves 7, 2, 3 and 4 show the model-predicted concentrations in water, phytoplankton, prey and predatory fish. Curve 5 gives the assumed time-dependent outflow rate from the catchment. Default Kd=0.1 default phytoplankton uptake rate 68.3 10 (1/month)...

It has been argued that Cs has a large particle affinity (Broberg and Andersson 1989 Riise et al. 1990 Salbu et al. 1991), but that may not be generally valid. To emphasize the uncertainty in these matters, tests with different Kd-values have been conducted. Figure 9.8A gives results for Kd=0.1 and Fig. 9.5B for Kd=0.9. One can note that about the same Cs-concentrations in water, phytoplankton, prey and predator can be obtained for the two Kd-values - but only if at the same time the phytoplankton uptake rate is changed by a factor of 9. 

Amount dissolved in water(t) = Amount dissolved in water(t - dt) + (Dissolved -Phytoplanktonic uptake - Lake outflow diss) dt INIT Amount dissolved in water = 1... 

Phytoplanktonic uptake = 1 Pelagic uptake rate Amount dissolved in water DOCUMENT Units are 1/year for Hg, 1/month for Cs and 1/unit of time more generally. 

Phytoplanktonic uptake + Bioaccumulation plank to prey - Outflow from... 

To understand the bay s ecosystem and water quahty comprehensively, we must have enough understanding of biologic, chemical, and physical processes. Nutrients enter the bay from river, atmosphere, industry and wastewater treatment plants, and transferred by the effect of advection and diffusion in the bay. Nutrients are also transformed to organic matter by phytoplankton uptake or mineralized by adsorption. Even if it settles down on the seabed, it will be recycled as suspended matter by wave-induced flow or remineralized by bacteria. 

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