Effects of Ozone-Related Increased UV-B Fluences on Photosynthesis, Photoadaptation and Viability of Phytoplankton in Antarctic Waters

平流层臭氧浓度下降， 南极洲的紫外线强度增加 辐射在UV-B部分的光谱入射在 地球表面的“臭氧洞”。现在全世界都有 担心这种增强的紫外线辐射通量可能会导致严重的 对南大洋海洋生态系统的危害。这个项目， 包括实地和实验室研究，将有助于 确定紫外线-B辐射增强对 浮游植物，并将这种影响与上层臭氧联系起来 浓度的通过NSF操作的UV- 帕尔默站的分光辐射计将直接适用于 对观察到的生物效应的解释。初级 将注意UV-B辐射对 光合速率，对DNA的损害，导致损失的 细胞活力，并对利率和程度， 浮游植物可以通过产生 专门的保护颜料。对UV-B的差异敏感性 占优势的浮游植物物种或群体也将 因为这些差异可能会产生重要的后果， 对无南极沃茨食物网结构的影响。为 该项目的活动将涵盖9月至 12月，由此产生的数据集应涵盖 臭氧层空洞的最大发展，以及时间 夏至。这个项目很重要，因为它将 阐述以前的调查结果，并详细说明 紫外线对浮游植物的伤害，以及 评估细胞可以对抗它的防御能力。

Decreased concentrations of ozone in the stratosphere over Antarctica have resulted in increased levels of ultraviolet radiation in the UV-B portion of the spectrum incident at the earth's surface beneath the 'ozone hole'. There is now world-wide concern that this enhanced flux of UV radiation may cause serious harm to the marine ecosystem in the Southern Ocean. This project, which includes field and laboratory studies, will help to determine the effects of enhanced levels of UV-B radiation on phytoplankton, and to relate such effects to overlying ozone concentrations. UV levels determined from the NSF-Operated UV- Spectroradiometer at Palmer Station will be directly applicable to the interpretation of observed biological effects. Primary attention will be given to the effects of UV-B radiation on photosynthetic rates, on damage to DNA with resulting loss of cell viability, and on the rates and extent to which phytoplankton can minimize cellular UV damage by production of specialized protective pigments. Differential sensitivity to UV-B of dominant phytoplankton species or groups will also be determined, as such differences might have important consequences on the structure of the food web in antarctic waters. As the project's activity will cover the period from September through December, the resulting data set should encompass the period of maximal development of the ozone hole, as well as the time of the summer solstice. This project is important because it will elaborate previous findings and address in detail the extent and the nature of ultraviolet damage to phytoplankton, as well as evaluate the kinds of defenses cells can muster against it.