Extremely sensitive and precise measurements of lead and silver in the ocean have revealed marked anthropogenic perturbations of their global biogeochemical cycles. Lead was the most contaminated ? relative to its natural concentration - trace element in the oceans in the previous century, and silver now appears to be assuming that dubious title.
In this study, researchers at the University of California at Santa Cruz, in collaboration with colleagues at several other U.S. and international institutions, will study the distribution of these two metals in the North Pacific basin. Proposed analyses of spatial and temporal variability of the two metals in the North Pacific, where there is a surprising dearth of data for either, will provide both basic information on their natural biogeochemical cycles and quantification of industrial perturbations of those cycles. In addition, contrasting aspects of those cycles, along with the demonstrated applicability of stable lead isotopic ratios to characterize and distinguish diverse natural and industrial sources of lead in the biosphere, make the two metals complementary geotracers of other historic and emerging anthropogenic pollutants.
This work will have a number of significant broader impacts. The project, headed by a female postdoctoral researcher, will include several undergraduates, with at least one intern from the California Alliance for Minority Participation in Science, Engineering and Mathematics Program (CAMP), which is directed at UCSC by the CoPI. This NSF funded program, which has measurably increased the number of under-represented students graduating from UC and continuing on to graduate studies over the past decade, has recently been funded for 5 more years. The project will also include many collaborations, both U.S. and international..
