Monterey Bay Aquarium Research Institute
2004 projects
Upper ocean biogeochemistry

Observing complexity in the coastal ocean

Project Manager/Lead Scientist: John Ryan

The focus in 2004 is to study two dynamic regions of Monterey Bay that are at present poorly understood:

  1. The near-shore central bay where a plume emanates into the bay from the opening of Elkhorn Slough & Moss Landing Harbor
  2. The outer southern shelf off Monterey Peninsula where strong exchanges with the adjacent sea are evident in satellite imagery. 

Nearshore plume processes: Observations of Monterey Bay from aircraft reveal a significant scale (20-30 square kilometers), very complex structure, and strong variability in the plume that emanates from the Elkhorn Slough and Moss Landing harbor. The plume represents the primary year-round exchange between estuarine and coastal oceanic waters of Monterey Bay, but it remains poorly understood with regard to nutrient and sediment transports and ecosystem responses.

To better understand this exchange and its consequences, we will draw upon the strengths of a few key MBARI assets: the Dorado AUV, the MBARI vertical profiler (MVP), and the R/V Zephyr. The spectrum of measurements being made from Dorado is outstanding, and the science enabled is thus broad and multidisciplinary. During 2004 we will augment and apply capabilities of Dorado. Specifically, we will develop and test plume-responsive control behavior that will optimize sampling of amorphous, evolving plumes. Salinity, nitrate and turbidity measurements already operational on the AUV will provide strong signals for developing and testing control behavior. During the first wet season, we will characterize the plume and its variability using Zephyr-based mapping that will serve as the basis for Dorado sampling design during the second wet season. We will also employ continuous vertical profiling of water properties and ocean currents to characterize plume vertical structure and mixing within the bay.

These efforts will not only advance our understanding of this nearshore exchange between ocean and estuary in Monterey Bay, but also initiate plume-responsive control for Dorado that will be applicable from shallow river plumes to deep-sea vent plumes.

The outer southern shelf: Strong exchange between Monterey Bay and the adjacent sea is often evident in satellite imagery, but poor temporal resolution and lack of vertical resolution in satellite imagery prevents accurate characterization of the physical, chemical and biological exchanges of this region. We will fill this observational gap also using the combined strengths of Dorado, MVP, and Zephyr.  Application of this observational fleet will permit thorough characterization of the environmental variability in both study regions. We have found synergy in combining thorough understanding of environmental variability with knowledge of microbial species and their variability, as the MBARI Environmental Sample Processor (ESP) can uniquely provide. We will collaborate with the ESP team during their 2004 deployments to advance this synergistic combination of unique MBARI resources.

Last updated: Feb. 05, 2009