UV Radiation in Antarctic Waters: Dynamics Response of Phytoplankton and Attenuation by Pigments

由于平流层臭氧水平的减少，南极海平面上的紫外线b辐射通量（UV-B, 280-320 nm）可能正在增加。先前的研究表明，水柱上部的海洋浮游植物受到天然紫外线辐射的抑制，因此，紫外线通量的进一步逐步增加可能对南极水域的食物网产生破坏性影响。Holm-Hansen建议用多通道光谱辐射计测量天然紫外线在光区的通量，并记录其对海洋浮游植物的影响。对微粒和溶解成分吸收的分析将有助于评估浮游植物和碎屑色素在紫外线辐射衰减中的作用。海洋就地研究将根据放射性碳的吸收速率来研究紫外线的短期影响和根据浮游植物生长速率来研究紫外线的长期影响。除了海洋就地研究外，还将进行使用人工光源的对照实验，以评估已知的紫外线剂量对分离的浮游植物培养物的影响，以及自然水样中不同物种的不同敏感性。利用高效液相色谱法、颗粒吸收光谱和荧光光谱分析包括紫外线吸收色素合成在内的光适应反应及其在保护和/或光合作用中的作用。这些关于浮游植物对不断增加的紫外线剂量水平的动态反应的研究对于了解南极臭氧减少/ UV- b水平增强的生物学后果将是重要的，并且通过建模工作，对预测世界海洋其他地方的紫外线影响将具有价值。

The flux of ultraviolet-B radiation (UV-B, 280-320 nm) at sea level in the Antarctic may be increasing due to decreases in stratospheric ozone levels. Previous studies have shown that marine phytoplankton in the upper portion of the water column are inhibited by natural UV radiation, and hence further progressive increases in the flux of UV may have damaging effects on the food web in Antarctic waters. Holm-Hansen proposes to measure the flux of natural UV in the euphotic zone with a multi-channel spectral radiometer and document its effect(s) on marine phytoplankton. Analysis of absorption by particulate and dissolved components will enable assessment of the role of phytoplankton and detrital pigments in the attenuation of UV radiation. Marine in situ studies will examine both short-term effects of UV based on rates of radiocarbon incorporation and long-term effects based on phytoplankton growth rates. In addition to marine in situ studies, controlled experiments using artificial light sources will be conducted to evaluate the effect of known UV doses on isolated phytoplankton cultures as well as the differential sensitivities of species in natural water samples. Photoadaptational responses involving synthesis of UV absorbing pigments and their role in protection and/or photosynthesis will be analyzed using HPLC, and particulate absorption and fluorescence spectroscopy. These studies of the dynamic response of phytoplankton to increasing dose-levels of UV will be important for understanding the biological consequences of reduced ozone/enhanced UV-B levels in the Antarctic and, through modeling efforts, will be of value in predicting UV effects elsewhere in the world's oceans.