U.S.-Sweden Cooperative Research: Scaling and Models of Sediment Biogeochemical Nutrient Transformations in the Baltic Sea

9300474 Conley这个为期三年的奖项支持马里兰大学环境与河口研究中心的Daniel J. Conley和斯德哥尔摩大学系统生态学系的Fredrik Wulff在海洋生态学方面的美国-瑞典合作研究。这项研究的目的是确定控制波罗的海沉积物中营养物质净交换的过程。通过理论分析、实地和实验室实验研究以及模型核查，调查人员将共同努力确定波罗的海不同地理区域的生物地球化学控制机制。来自瑞典、波兰和俄罗斯的研究人员计划每年进行一次巡航。海洋系统中的生物地球化学循环和过程是当地沿海地区和浅海的主要关注点。波罗的海为研究这些过程提供了极好的机会，因为它是一个定义明确且被深入研究的河口，经历了由富营养化和人类活动引起的大规模环境变化。波罗的海的富营养化物质和有毒物质（氮和磷）都在增加，这反过来又导致沉积物中二氧化硅的储存和低水平的溶解硅酸盐。这些低水平可能会对物种组成和食物网产生未来的影响。为了扭转目前富营养化的趋势，不仅在波罗的海，而且在其他河口也发现了富营养化，研究人员将从研究地点提取沉积物岩心，并根据其物理化学特征，以及硅酸盐，溶解态氮和磷的通量速率来表征它们。这些数据将用于开发描述营养物质交换的过程导向模型。这项研究将补充和加强目前的数据，并促进对波罗的海变化的基本机制的了解。康利博士为这次合作带来了二氧化硅双地球化学循环方面的专业知识。瑞典调查员在水和沉积物之间氮、磷和二氧化硅通量的生物地球化学建模方面的专业知识补充了这一点。* * *

9300474 Conley This three-year award supports U.S.- Sweden cooperative research in marine ecology between Daniel J. Conley of the University of Maryland's Center for Environmental and Estuarine Studies and Fredrik Wulff of the Department of Systems Ecology, Stockholm University. The objective of the research is to determine the processes controlling the net exchange of nutrients from sediments of the Baltic Sea. Using theoretical analyses, field and laboratory experimental studies and model verifications, the investigators will work together on determining biogeochemical control mechanisms in varying geographical areas of the Baltic Sea. Annual cruises are planned with researchers from Sweden, Poland and Russia. Biogeochemical cycles and processes in a marine system are of prime concern for local coastal zone and shallow seas. The Baltic Sea offers excellent opportunities to study these processes since it is a well-defined and intensively studied estuary that has experienced large-scale environmental changes from eutrophication and human activity. Both eutrophying substances and toxic substances (nitrogen and phosphorus) are increasing in the Baltic, which in turn give rise to storage of silica in the sediments and low levels of dissolved silicate. These low levels may have future consequences on species composition and the food web. In order to reverse the current trends in eutrophication, not only found in the Baltic Sea, but also in other estuaries, the investigators will take sediment cores from the study sites and characterize them in terms of their physico-chemical features, and the flux rates for silicate, dissolved nitrogen species, and phosphorus. These data will be used to develop a process oriented model describing the exchanges of nutrients. The research will complement and enhance the present data and advance understanding of the mechanism underlying changes in the Baltic Sea. Dr. Conley brings to this collaboration expertise in the bi ogeochemical cycling of silica. This is complemented by the Swedish investigator's expertise in biogeochemical modeling of fluxes of nitrogen, phosphorus and silica between water and sediments. ***