HISTORICAL ECOLOGY OF FLORIDA KEYS CORAL REEF ECOSYSTEMS

John Largier (UCD)

Link to NOAA Strategic Plan: NOAA's Mission Goal 1: Protect, Restore, and Manage the Use of Coastal and Ocean Resources through Ecosystem-based Management; Goal 3: Serve Society’s Needs for Weather and Water Information

RESEARCH OBJECTIVES AND SPECIFIC PLANS TO ACHIEVE THEM

Cordell Bank (http://cordellbank.noaa.gov) is a center of productivity on the Northern California shelf, rising to within 60 meters of the surface of the ocean from the surrounding deeper waters (Figure 1). The Bank is situated roughly 65 nautical miles downstream from a major and persistent upwelling center at Point Arena to the north, and is occasionally impacted by outflows that arrive from San Francisco Bay, 40 nautical miles to the south. Inter-annual and intra-annual variability in the various oceanographic influences can be expected to lead to variability in the productivity of the Cordell Bank National Marine Sanctuary ecosystem.

In collaboration with the Cordell Bank National Marine Sanctuary, Bodega Marine Laboratory (BML) has recently completed the design and deployment of a mooring on the Cordell Bank (Figure 2). The World Meteorological Organization (WMO) number assigned to the mooring is 46095. The project goals are: (1) to monitor and document physical and biological conditions on the Bank, (2) to increase understanding of the relationship between upwelling / productivity at the Bank and the physical forcing, and (3) to educate the public about oceanic processes, and this valuable Sanctuary in particular. Instruments record top-to-bottom water current profiles and wind speed / direction. Sea-surface temperature, salinity, chlorophyll fluorescence, and turbidity are also monitored. The measurements are transmitted back to shore real-time via satellite. The data will be made available to the public, researchers, and partners through the BML website (http://www.bml.ucdavis.edu/boon/cbb.html), and the National Data Buoy Center (http://www.ndbc.noaa.gov). In combination with the Cordell Bank Oceanographic Monitoring Program (CBOMP) monthly surveys and the Bodega Ocean Observing Node (BOON) data, the mooring measurements will allow for much improved assessment, monitoring and understanding of the essential characteristics of this pelagic habitat.

RESEARCH ACCOMPLISHMENTS

Researchers at Bodega Marine Laboratory and the Cordell Bank National Marine Sanctuary worked together to define the system requirements and deploy the buoy. With BML providing much of the instrumentation, the mooring definition has been expanded slightly from that outlined in the original scope of work. Based on a competitive bidding process, the system integration, buoy hull, and controller were provided by Axys Technologies, Inc.

The instrument suite includes: (1) an R.M. Young anemometer, (2) a Nortek 400 kHz downward-looking ADCP, (3) a Sea-Bird Electronics temperature / salinity sensor, and (4) a WETLabs fluorescence / turbidity sensor. The measurements are synthesized into a single data stream by the Axys WatchMan 500 controller and sent back to shore via the Iridium satellite system. System parameters can be changed remotely through the WatchMan 500 controller, allowing sampling strategies to be modified in response to changing environmental conditions. Solar-rechargeable batteries provide system power. Spare controller channels are available for future expansion of the instrumentation suite.

For initial evaluation and testing, most of the instrumentation has been set to sample for 10 minutes every hour. The averaged data are sent back to shore as a single lengthy text message. With the exception of the ADCP data, these “hourly estimates” can be viewed graphically using Axys software. BML personnel are currently developing scripts to facilitate easy viewing of the ADCP measurements. Once the measurements have been verified, and data is flowing smoothly from the mooring, through BML, and to the general public, a higher-resolution sampling scheme may be implemented.

The WMO number for the buoy (46095) has been provided by personnel at the National Data Buoy Center (NDBC). Data directories have been set up to allow BML to send the measurements directly to NDBC over the internet via the File-Transfer-Protocol (FTP). BML and NDBC are currently working together to determine the most appropriate file format for sending the data. The challenges are determining the appropriate tags, or descriptors, for the measurements, and ensuring that the chosen tags interface seamlessly with the NDBC data parsing system.

Operationally, plans call for full mooring maintenance to be performed annually or every-other-year using the NOAA ship McArthur II. Instruments will be serviced approximately every 2 months using either the Sanctuary vessels or the R/V Mussel Point, operated by Bodega Marine Laboratory. Hopefully sanctuary funding will allow the buoy to continue to be operated for at least the next several years, and to become an established component of the Central and Northern California Ocean Observing System (CeNCOOS).

Fig. 1 Cordell Bank shaded relief image. Depths are in meters. The bank is downstream of the major upwelling center at Point Arena [figure adapted from NOAA, 2002, courtesy of M. Carver]

Fig. 2 The Cordell Bank buoy, WMO number 46095, after deployment. Sensors on the buoy are used to record wind speed / direction, water current profiles, and sea-surface fluorescence, turbidity, temperature, and salinity. Measurements are sent back to shore via satellite