U.S.-Sweden Cooperative Research: Long-term Historical Research Record of Cyanobacterial Blooms in the Baltic Sea

这项为期两年的奖项将支持美国和瑞典合作研究波罗的海蓝藻水华的历史，合作伙伴是杜兰大学的Thomas S.Bianci和斯德哥尔摩大学的Ragnar Elmgren。他们研究的目的是通过古生态方法确定波罗的海蓝藻水华的长期记录。他们将使用化石、硅质微化石和生物来源的无定形二氧化硅中的标记颜料来确定过去的浮游植物组合。成岩组分和放射性核素将用于确定沉积速率和再悬浮事件。比安奇博士将生物标记物作为碳的示踪物方面的专业知识带到了这一合作中。瑞典在波罗的海富营养化研究和沉积物地球化学评估方面的专门知识对此起到了补充作用。过去40年来，波罗的海营养盐负荷的增加导致了严重的富营养化问题。虽然近年来在控制营养投入方面做出了协调努力，但仍然存在许多问题。例如，蓝藻水华在夏季繁殖，这些水华的原因在很大程度上仍不清楚。该项目将增进我们对这些水华发生的原因以及它们是否是波罗的海的自然现象的理解，这些现象不一定与人为输入有关。关于蓝藻水华的起源及其对长期营养限制的影响的信息将有助于制定波罗的海环境管理计划。

This two-year award will support U.S.-Sweden cooperative research on the history of cyanobacterial blooms in the Baltic Sea between Thomas S. Bianchi of Tulane University and Ragnar Elmgren of Stockholm University. The objective of their research is to determine through paleoecological methods, the long-term record of cyanobacterial blooms in the Baltic Sea. They will use marker pigments from fossils, siliceous microfossils and biogenic amorphous silica to determine past phytoplankton assemblages. Petrogenic components and radionuclides will be used to determine sedimentation rates and resuspension events. Dr. Bianchi brings to this collaboration expertise in biomarkers as tracers of carbon. This is complemented by Swedish expertise in eutrophical studies in the Baltic and in geochemical assessment of sediments. Increased nutrient loading over the past four decades in the Baltic Sea has resulted in significant eutrophication problems. While there has been a concerted effort in recent years to control nutrient inputs, many problems still exist. For example, cyanobacterial blooms proliferate in the summer and the causes of these blooms remain largely unknown. The project will advance our understanding of why these blooms occur and whether they are a natural phenomena of the Baltic Sea that are not necessarily associated with anthropogenic inputs. Information about the origins of cyanobacterial blooms and the effects on long-term nutrient limitations will contribute to the development of an environmental management plan for the Baltic Sea.