Ultraviolet Radiation Induced Changes in the Patterns of Production and Composition of Biochemical Compounds in Antarctic Phytoplankton

紫外线辐射引起南极浮游植物生化化合物生产模式和组成的变化

• 批准号: 0126150
• 负责人: JOAQUIM GOES
• 金额: $ 26.34万
• 依托单位: Bigelow Laboratory for Ocean Sciences
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-07-01 至 2006-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0126150&HistoricalAwards=false
• 关键词: Ultraviolet; Radiation; Induced; Changes; Patterns

Goes0126150There is sufficient evidence to show that present levels of incident ultraviolet radiation (UVR, 280-400nm) are impairing phytoplankton productivity in the Southern Ocean. Yet, efforts at extrapolating these findings to allow accurate and unambiguous predictions of the consequences of UVR on the Antarctic marine food web and biogeochemical cycles in the sea have been confounded with uncertainty. Estimated impacts to the Antarctic marine ecosystem range from insignificant to catastrophic. This disparity has been attributed to lack of information in key areas of UVR photobiology and photochemistry. Generally, studies have been based on broadband UVR, and do not take into account competing responses of phytoplankton at different wavelengths across the UVR waveband. Such information is critical if we are to understand the consequences of UVR enhancement on carbon assimilation by marine phytoplankton and its consequences for the food web and biogeochemical cycles. This is especially true in regions like the Antarctic where stratospheric ozone concentrations can decrease by about 50% each spring altering the proportion of UVB (280-320nm) and UVA (320-400nm) radiation that phytoplankton receive during their growth season. This project will systematically investigate changes in the production rates and composition of biochemical compounds within Antarctic phytoplankton cells under spectrally defined conditions. Investigations of both laboratory cultures and natural populations of Antarctic phytoplankton will be undertaken to understand 1) how phytoplankton cellular biochemical processes are impacted by the interplay between the different UVR wavelengths and visible light, 2) how UVR sensitivity varies across taxonomic groups of phytoplankton and 3) whether this difference in sensitivity is responsible for the dominance of one species over the other. The effect of UVR exposure on nutrient uptake by phytoplankton cells will also be studied. This information will help ascertain the role of UVR in the phytoplankton dynamics of the Southern Ocean.

Goes0126150有足够的证据表明，目前入射的紫外线辐射(UVR，280-400纳米)正在削弱南大洋的浮游植物生产力。然而，为了能够准确和明确地预测紫外线辐射对南极海洋食物网和海洋生物地球化学循环的影响，推断这些发现的努力与不确定性混为一谈。估计对南极海洋生态系统的影响从微不足道到灾难性不等。这种差异被归因于在UVR光生物学和光化学的关键领域缺乏信息。一般来说，研究是基于宽带UVR的，没有考虑浮游植物在不同波长的UVR波段的竞争反应。如果我们要了解紫外线辐射增强对海洋浮游植物碳同化的影响，以及它对食物链和生物地球化学循环的影响，这些信息是至关重要的。在南极这样的地区尤其如此，那里的平流层臭氧浓度每年春季会下降约50%，从而改变浮游植物在生长季节接收的UVB(280-320 nm)和UVA(320-400 nm)辐射的比例。该项目将系统地研究南极浮游植物细胞在光谱定义的条件下的生物化学化合物的生产率和组成的变化。将对南极浮游植物的实验室培养和自然种群进行调查，以了解1)不同的紫外线波长和可见光之间的相互作用如何影响浮游植物的细胞生化过程，2)不同的浮游植物分类群对紫外线的敏感性如何变化，以及3)这种敏感性的差异是否导致了一个物种对另一个物种的优势。还将研究紫外线照射对浮游植物细胞吸收营养物质的影响。这些信息将有助于确定UVR在南大洋浮游植物动态中的作用。