Phytoplankton radiation

A month-long study of the effects of ultraviolet radiation (UV) on phytoplankton and ice-algae collected from Arthur Harbor, Anvers Island, Antarctica, was carried out during November-December 1987. The parameters studied included primary production rates, photosynthetic... 

Antarctic phytoplankton. In this chapter we will focus on the effects of ultraviolet radiation on Antarctic phytoplankton. We will discuss the results of an investigation which we undertook in late austral... 

Short-term (i.e., 4 hr) exposure of phytoplankton and ice-algae to UV radiation produced no significant changes in the concentrations of... 

Figure 2. Schematic drawing of the four experimental tanks and chambers used to investigate the effects of UV radiation of Antarctic phytoplankton and ice-algae. (Reproduced with permission from reference 23. Copyright 1990 Springer-Verlag, Berlin.)...

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. 

Sunlight can enter a body of water to a depth defined as the photic zone (Figure 7.13). The lower boundary of the photic zone is the region where the light levels have fallen to 1 per cent of their surface value. The photic zone may be as little as 1 m where the water is unclear (due to particulates for example) or may extend up to 200 m. Within this region phytoplankton are capable of photosynthesis whereas below this region no light penetrates and the oceans are dark. Protection from all radiation is possible below 200 m and will allow chemistry and bond formation to occur. 

Karentz D, Cleaver JE, Mitchell DL (1991) Cell survival characteristics and molecular responses of Antarctic phytoplankton to ultraviolet-B radiation. J Phycol 27 326-341... 

Smith RC, Prezelin BB, Baker KS, Bidigare RR, Boucher NP, Coley T, Karentz D, MacIntyre S, Matlick HA, Menzies D, Ondrusek M, Wan Z, Waters KJ (1992) Ozone depletion ultraviolet radiation and phytoplankton biology in Antarctic waters. Science 255 952-959 Sommaruga R, Psenner R (1997) Ultraviolet radiation in a high mountain lake of the Austrian Alps air and underwater measurements. Photochem Photobiol 65 957-963 Swanson AK, Druehl LD (2002) Induction, exudation and the UV protective role of kelp phlorotannins. Aquat Bot 73 241-253... 

Goes, J. I., N. Handa, S. Taguchi, T. Hama, and H. Saito. 1995. Impact of UV radiation on the production patterns and composition of dissolved free and combined amino acids in marine phytoplankton. Journal of Plankton Research 17 1337-1362. 

Pausz, C., and G. J. Herndl. 1999. Role of ultraviolet radiation on phytoplankton extracellular release and its subsequent utilization by marine bacterioplankton. Aquatic Microbial Ecology 18 85-93. 

Phytoplankton production RpA in environment A is a function of solar radiation Ea, concentration of nutrients nA, temperature TA, phytoplankton biomass pA, and concentration of pollutants A. There are many models that describe the photosynthesis process (Legendre and Legendre, 1998 Legendre and Krapivin, 1992). For the description of this function in the present study, an equation of Michaelis-Menten type is used (block MFB) ... 

Various MAA compounds have different responses to partitioned radiation exposures. In whole water samples of Antarctic phytoplankton monitored over a 2-week period, shinorine and porphyra-334 increased in concentration with exposure to either total sunlight or visible light alone.173 In contrast, mycosporine-glycine and palythine concentrations increased only under total sunlight treatments and not when exposure was limited to the visible band. MAA-specific increases also occur in unicellular freshwater Chlorophyta species.131... 

Helbling, E. W., Villafane, V., and Holm-Hansen, O., Effects of ultraviolet radiation on Antarctic marine phytoplankton photosynthesis with particular attention to the influence of mixing, in Ultraviolet Radiation and Biological Research in Antarctica, Weiler, C. S. and Penhale, P. A., Eds., American Geophysical Union, Washington, D.C., 1994, 207. 

Lesser, M. P, Acclimation of phytoplankton to UV-B radiation — oxidative stress and photoinhibition of photosynthesis are not prevented by UV-absorbing compounds in the dinoflagellate Prorocentrum micans, Mar. Ecol. Prog. Ser., 132, 287, 1996. 

Yentsch, C. S. and Yentsch, C. M., The attenuation of light by marine phytoplankton with specific reference to the absorption of near-UV radiation, in The Role of Solar Ultraviolet Radiation in Marine Ecosystems, Calkins, J., Ed., Plenum Press, New York, 1982, 691. 

Lesser, M. P., Neale, P. J., and Cullen, J. J., Acclimation of antarctic phytoplankton to ultraviolet radiation ultraviolet-absorbing compounds and carbon fixation, Mol. Mar. Biol. Biotech, 5,314,1996. 

Villafane, V. E., Helbling, E. W., Holm-Hansen, O., and Chalker, B. E., Acclimitization of Antarctic natural phytoplankton assemblages when exposed to solar ultraviolet radiation, J. Plankton Res., 17, 2295, 1995. 

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