MUSE 2: Iron regulation of ocean ecosystems
Project Manager: Steve Fitzwater
Lead Scientist: Ken Johnson

The goals of this Iron Regulation of Ocean Ecosystems project are to extend our understanding of the roles that iron plays in regulating ecosystem structure and the impact of iron on biogeochemical cycles and climate. We will focus on two projects. First, we will continue our time series observations of iron concentrations and biogeochemical processes in Monterey Bay. As part of this effort, we will study in more detail the interaction of dissolved iron with particles. Moss Landing Marine Laboratories is acquiring a High Resolution, Inductively Coupled Mass Spectrometer that will be available as a regional facility. This instrument will be key to enabling the study of particle composition.

Second, we propose to build upon the 2000 MOOS Upper-water-column Science Experiment (MUSE) experiment with a comparative field study of trace metal cycling and biological response at the upwelling centers north (Davenport) and south (Pt. Sur) of Monterey Bay. There is a fundamental difference between these two systems: during summer and fall there is typically very much less chlorophyll visible with the SeaWIFS satellite in the Pt. Sur area despite the fact that upwelling, indicated as low surface temperature, may be more intense to the south.

This experiment is key to the development of an operational ecosystem observatory in the Monterey Bay region. We must understand the processes that regulate the development of phytoplankton communities within the observatory area. Our working hypothesis, based on earlier work by Ken Bruland’s laboratory and our work in Monterey Bay, including MUSE, is that the much narrower shelf in the Pt. Sur region is a weaker source of iron and the phytoplankton communities in the Pt. Sur region are, therefore, strongly iron limited. We propose to undertake this study using a combination of classical observations with surface ships and autonomous observations using the Environmental Sample Processor (ESP). We will coordinate our field efforts with the deployment of the ESP that is planned by Scholin’s lab for summer 2002. This will provide synergy between both field efforts.