Collaborative Research: UV Effects on Marine Production by Bacteria and Phytoplankton Assessing the Impact of UVB

合作研究：紫外线对细菌和浮游植物海洋生产的影响评估 UVB 的影响

• 批准号: 9814178
• 负责人: Wade Jeffrey
• 金额: $ 15.67万
• 依托单位: University of West Florida
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-10-01 至 2002-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9814178&HistoricalAwards=false
• 关键词: Collaborative; Research; UV; Effects; Marine

U.V. Effects on Marine Production by Bacteria and Phytoplankton: Assessing the Impact of UVB. Ultraviolet radiation (UVR, 290-400 nm) from the sun penetrates to significant depths in many marine environments and a variety of studies have indicated its ecological importance. Stratospheric ozone depletion is changing the spectral composition of solar LTVR to varying degrees in different locations by increasing levels of biologically harmful, short wavelength UVB (290-320 nm). Previous work has shown that both UVB and the longer wavelength UVA (320-400 nm) affect marine carbon cycling, primarily through effects on phytoplankton and bacterioplankton which comprise the base of oceanic food webs. While phytoplankton are responsible for carbon fixation, bacterioplankton play a vital role in the mineralization of nutrients and provide a trophic link to higher organisms. Assessing the impact of UV on these processes during variations in ozone and water transparency requires accurate knowledge of spectral dependence. This dependence is described by a biological weighting function (BWF). Significant effort has been devoted in the last two decades to resolving BWFs for biological processes controlling rates of primary production in aquatic environments (i.e. photoinhibition). Compared to reports of UV effects on phytoplankton, however, studies of the impact and effects of UVR on bacterioplankton are in their relative infancy. Previous work with bacterioplankton has been limited to broad spectrum analysis (i.e. UVA vs. UVB). Unfortunately, such limited spectral resolution precludes prediction, particularly of the effects of increased UVB due to ozone depletion. The principal goal of this project is to develop biological weighting functions for inhibition of bacterioplankton production using DNA, RNA, and protein synthesis as representative biological processes. Biological weighting functions for inhibition of DNA, RNA, and protein synthesis will be determined for diverse marine environments (Chesapeake Bay and Gulf of Mexico) using polychromatic light regimes and compared to similar functions measured for phytoplankton. Models will be developed and compared to in situ measurements of production and examined for significant disparities. Experiments with pre- and post- fractionated samples will indicate how bacterioplankton coupling influences UV responses. Time series assays will define how response is related to exposure and whether damage is counteracted by photoreactivation. This study will increase our understanding of the spectral sensitivity of natural assemblages of bacterioplankton in diverse environments and of the role of UVR in controlling marine ecosystems with particular reference to increased UVB associated with stratospheric ozone depletion.

紫外线。细菌和浮游植物对海洋生产的影响：评估 UVB 的影响。 来自太阳的紫外线辐射（UVR，290-400 nm）在许多海洋环境中都能穿透到很深的地方，各种研究都表明了其生态重要性。平流层臭氧消耗增加了对生物有害的短波 UVB（290-320 nm）水平，从而不同程度地改变了不同地点太阳 LTVR 的光谱组成。先前的研究表明，UVB 和较长波长的 UVA（320-400 nm）都会影响海洋碳循环，主要是通过影响构成海洋食物网基础的浮游植物和浮游细菌。浮游植物负责碳固定，而浮游细菌在营养物矿化中发挥着至关重要的作用，并为高等生物提供营养联系。评估臭氧和水透明度变化期间紫外线对这些过程的影响需要准确了解光谱依赖性。这种依赖性由生物权重函数 (BWF) 描述。 在过去的二十年里，人们投入了大量的努力来解决控制水生环境中初级生产力的生物过程的 BWF（即光抑制）。然而，与紫外线对浮游植物影响的报道相比，紫外线对浮游细菌的影响和作用的研究还处于相对初级阶段。以前对浮游细菌的研究仅限于广谱分析（即 UVA 与 UVB）。不幸的是，如此有限的光谱分辨率无法预测，特别是由于臭氧消耗而导致 UVB 增加的影响。该项目的主要目标是开发生物加权函数，以 DNA、RNA 和蛋白质合成作为代表性生物过程来抑制浮游细菌的产生。将使用多色光方案确定不同海洋环境（切萨皮克湾和墨西哥湾）抑制 DNA、RNA 和蛋白质合成的生物权重函数，并与浮游植物测量的类似函数进行比较。将开发模型并与现场生产测量进行比较，并检查是否存在显着差异。 分馏前和分馏后样品的实验将表明浮游细菌耦合如何影响紫外线响应。时间序列分析将定义反应如何与暴露相关，以及损伤是否可以通过光再激活来抵消。这项研究将增进我们对不同环境中浮游细菌自然组合的光谱敏感性以及紫外线在控制海洋生态系统中的作用的了解，特别是与平流层臭氧消耗相关的紫外线B增加。