Antarctic phytoplankton

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... 

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. 

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... 

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... 

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. 

Koike, I., Holm-Hansen, O., and Biggs, D. C. (1986). Inorganic nitrogen metabohsm by Antarctic phytoplankton with special reference to ammonium cychng. Mar. Ecol. Prog. Ser. 30, 105—116. Kramer, R. (1994). Secretion of amino acids by bacteria Physiology and mechanism. Fed. Eur. Microbiol. Soc. Microbiol. Rev. 13, 75—94. 

Cochlan, W. P., Bronk, D. A., Coale, K. H. (2002a). Trace metals and nitrogenous nutrition of Antarctic phytoplankton Experimental observations in the Ross Sea. Deep-Sea Res 49, 3365-3390. 

Helbling, E. W., ViUafahe, V., Holm-Hansen, O. (1991). Effects of iron on productivity and size distribution of Antarctic phytoplankton. Eimnol. Oceanogr. 36, 1879-1885. 

Neori, A., Holm-Hansen, O. (1982). Effects of temperature on rate of photosyntheses in Antarctic phytoplankton. Polar Biol. 1, 33-38. 

Tilzer, M. M., Elbrachter, M., Gieskes, W. W., Besse, B. (1986). Light—temperature interactions in the control of photosynthesis in Antarctic phytoplankton. Polar Biol. 5, 105—111. 

Jacques, G. (1983). Some ecophysiological aspects of Antarctic phytoplankton. Polar Biol. 2, 27-33. Jahnke, R., Reimers, C., and Raven, D. (1990). Intensification of recycling of organic matter at the sea floor near ocean margins. Nature 348, 50-54. 

Sommer, U. (1986). Nitrate- and silicate-competition among Antarctic phytoplankton. Mar. Biol. 91, 345-351. 

M. Vernet, E.A. Brody, O. Holm-Hansen, B.G. Mitchell (1994). The response of Antarctic phytoplankton to ultraviolet radiation absorption, photosynthesis, and taxonomic composition. In C.S. Weiler, P.A. Penhale (Eds). Ultraviolet Radiation in Antarctica Measurements and Biological Effects (pp. 143-158). American Geophysical Union, Washington, D.C. 

P.J. Neale, R.F. Davis, J.J. Cullen (1998). Interactive effects of ozone depletion and vertical mixing on photosynthesis of Antarctic phytoplankton. Nature, 392,585-589. 

Figure 3. Comparison of biological weighting functions for UV inhibition of photosynthesis for Rhode River (mid-latitude site, North America) and Antarctic phytoplankton. [Reprinted with permission from Banaszak and Neale [80], Figure 2, p. 597, Copyright 2001, The American Society for Limnology and Oceanography, Inc.]...

UV exposure generally inhibits phytoplankton photosynthesis and recent results indicate that, on the average, BWFs for such inhibition are similar for mid-latitude and Antarctic phytoplankton. UV also indirectly affects phytoplankton photosynthesis through its effects on the biological availability of iron and other trace metal nutrients. 

M.P. Lesser, P.J. Neale, J.J. Cullen (1996). Acclimation of Antarctic phytoplankton Ultraviolet absorbing compounds and carbon fixation. Mol Mar. Biol Biotechnol, 5, 314-325. 

S.Z. El-Sayed, F.C. Stephens, R.R. Bidigare, M.E. Ondrusek (1990). Potential effects of solar ultraviolet radiation on Antarctic phytoplankton, UV effects on biological processes. In N.V. Blough, R.G. Zepp, (Eds), Effects of Solar Ultraviolet Radiation on Biogeochemical Dynamics in Aquatic Environments (Technical Report WHOI-90-09, pp. 141-142). Woods Hole Oceanographic Institution. 

A.T. Davidson, H.J. Marchant, W.K. de la Mare (1996). Natural UVB exposure changes the species composition of Antarctic phytoplankton in mixed-culture. Aquat. Microb. Ecol, 10, 299-305. 

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