U.S.-Brazil Cooperative Study of Microbial Nitrogen Cycling in Brazilian Coastal Waters

9314610格雷夫特美国-巴西合作科学奖将支持马里兰大学的帕特里夏·格雷夫特和巴西圣保罗大学博士生帕特里夏·梅茨勒的合作。该项目旨在测量巴西海岸的浮游氮素转化。氮素营养在海洋初级生产中的重要性早已被认识到。它们的再生被认为是海洋初级生产者氮素的主要来源，但最终决定产量的是“新”氮的供应率。几乎没有对西南大西洋氮素转化速率的直接测量。在这个项目中，研究人员将应用15N稳定同位素示踪技术来研究巴西沿海和近海水域对氮通量的生理和营养动力学响应。这些实验将阐明浮游生物对新氮输入的大小和时间依赖反应之间的关系，以及对新氮和再生氮的依赖。这些研究将对双方都有利，因为它们为世界上采样不足的海洋部分提供数据，在巴西建立一个新的研究领域，并培训巴西学生进行这些实验的方法论。***

9314610 Glibert This US-Brazil Cooperative Science award will support the collaboration of Patricia Glibert of the University of Maryland and Patricia Metzler, a Ph.D. student at the University of Sao Paulo, Brazil. The project aims to measure planktonic nitrogen transformations off the coast of Brazil. The importance of nitrogenous nutrients in marine primary production has long been recognized. Their regeneration is known to be a major source of nitrogen for oceanic primary producers, but it is the rate of supply of "new" nitrogen which ultimately determines the amount of production. There have been virtually no direct measurements of the rates of nitrogen transformation in the western South Atlantic. In this project, the researchers will apply 15N stable isotope tracer techniques to investigate physiological and trophodynamic responses to nitrogen fluxes in Brazil's coastal and offshore waters. The experiments will elucidate the relationship between size- and time-dependent responses by plankton to new nitrogen inputs and the dependence on new versus regenerated nitrogen. These studies will benefit both sides by producing data for an undersampled part of the world's oceans, establishing a new area of research in Brazil, and training a Brazilian student in methodology for these experiments. ***