GLOBEC: Collaborative Research: Mesoscale and Finescale Mapping of Physical and Biological Fields in the Northern California Current System

Oregon State University, Corvallis OR

Investigators

Abstract

GLOBEC Collaborative Research: Mesoscale and Finescale Mapping of Physical and Biological Fields in the Northern California Current system This project will address the mesoscale physical and biological oceanographic distributions and processes that influence juvenile salmonid habitat along the Oregon/California coast. The PIs will characterize, across a range of spatial scales, the circulation patterns associated with upwelling fronts and coastal jets, particularly in response to coastal promontories such as Cape Blanco. These patterns will be evaluated in the context of the retention and/or loss of phytoplankton and zooplankton biomass and species within the coastal system in both spring and late summer. An instrumented, towed, undulating vehicle (a SeaSoar) will be used to map physical and biological distributions over spatial scales of 5-30 km. The SeaSoar will be equipped with appropriate sensors/instrumentation to measure physical fields (conductivity, temperature, depth), phytoplankton and bio-optical parameters (multiwavelength fluorometers and multi-wavelength absorption meters), copepod and small euphausiid mesozooplankton (Optical Plankton Counter), and large euphausiids and fish (HTI Acoustics system) for the mesoscale region extending from Newport, OR to Eureka, CA. In addition, there will be continuous underway surface sampling and along-track Acoustic Doppler Current Profiling (ADCP) of water transport. Immediately following each mesoscale survey will be a sequence of interconnected finescale mapping surveys of a region ca. 50 km offshore by 80 km along-shore, followed by process-oriented field studies. The different sampling regions are expected to display contrasting juvenile salmonid habitat properties due to the offshore transition of the main jet of the California Current at Cape Blanco which results in distinctly different physical and biological regimes north and south of the Cape.