Microbial Initiative in Low Oxygen areas off Concepcion and Oregon

Although Eastern Boundary Current Ecosystems (EBCE) represent less than 5% of the ocean?s surface, they support regions of high biological activity that contribute significantly to global elemental cycles. Of particular interest in these regions is the strong role that microbial assemblages play in the production and transport of organic matter from the well lit surface layers into the deeper ocean environment where it is remineralized.

Naturally occurring regions of hypoxia found along the EBCE support microbial communities that strongly affect marine and global biogeochemical cycles. Some of these largest regions, also known as Oxygen Minimum Zones (OMZs), are found in the upwelling areas of these EBCE along the North and South Pacific Ocean where their intensity, thickness, and temporal stability varies as a function of latitude.

With the support of the Gordon and Betty Moore Foundation (GBMF, Palo Alto, California), a study has been proposed to study the OMZ along the coast of Oregon-USA and Concepcion-Chile.

With this study we will understand the spatial and temporal variability of the OMZ along both the Oregon and Concepci=n regions, and their associated mechanisms, by integrating Physical, Biogeochemical, Microbial, and Paleo-oceanography. The outcome of the proposed effort will allow us to identify similarities and distinctions between the microbial assemblages inhabiting both regions, characterize physical and biogeochemical seasonal patterns in the development and maintenance of hypoxic zones over both shelves, and determine the long term changes in the seasonal fluctuation of oxygen concentration over the shelves with the use of paleo proxies.

Our study is aimed at developing databases to:

- compare the marine microbial assemblages associated with the seasonal hypoxia observed on the continental shelf off Concepcion, Chile, and Oregon, USA, and

- assess potential use of paleoceanographic approaches to characterize the interannual and long-term variability in local oceanographic physical, chemical, and biological conditions driving the development of these hypoxic coastal environments.

This project will be developed as an integrated effort between researchers at Oregon State University (OSU), Universidad de Concepcion (UdeC), Aarhus University (AU), Massachusetts Institute of Technology (MIT), and the University of Pennsylvania (Penn). Results from this proposed effort will significantly complement ongoing marine microbial and biogeochemical studies supported by the Agouron Institute in the permanent OMZ off northern Chile and Peru (see http://omz.udec.cl ).