Optical Phytoplankton Discriminator (OPD, a.k.a. BreveBuster) determines colored dissolved organic material (CDOM)
absorption spectra and particulate light absorbance spectra. The CDOM absorption spectra and correlation coefficients
(referred to as 'similarity indexes') between the particulate absorbance spectra and known phytoplankton classes are
available in real-time. Post-deployment processing calculates the best fit of multiple absorbance spectra from known
phytoplankton taxonomic classes. Through this process the OPD provides an estimate of the phytoplankton community
chlorophyll distribution among the classes included in the fit process. The major components of the OPD include: a
liquid-waveguide capillary cell (LWCC), a fiber-optic spectrometer, a tungsten-deuterium fiber-optic light and a 0.2
micrometer pore cross-flow filter. In-water operation of the OPD began in May 2003. Since that date 25 of these
instruments have been deployed on a variety of autonomous underwater vehicles, buoys, piers, channel markers and
boats and ships. It has been utilized in CDOM studies off the New Jersey coast, in HAB monitoring efforts in the Gulf
of Mexico and the Great Lakes, and in phytoplankton community structure studies in the Galapagos Islands and the
Mediterranean Sea. Most recently, it has been deployed to Veracruz, Mexico for HAB monitoring. Presently, several
OPD's operating on Slocum gliders and coastal buoys make up a local HAB observatory south of Tampa Bay, Florida,
partially supported by the NOAA/IOOS through GCOOS. This presentation will detail the OPD's capabilities and report
results from several of the deployments listed above. The ongoing effort to effectively visualize 4-D phytoplankton
community structure will be discussed.
Bioluminescence emitted from marine organisms upon mechanical stimulation is an obvious military interest, as it provides a low-tech method of identifying surface and subsurface vehicles and swimmer tracks. Clearly, the development of a passive method of identifying hostile ships, submarines, and swimmers, as well as the development of strategies to reduce the risk of detection by hostile forces is relevant to Naval operations and homeland security. The measurement of bioluminescence in coastal waters has only recently received attention as the platforms and sensors were not scaled for the inherent small-scale nature of nearshore environments. In addition to marine forcing, many ports and harbors are influenced by freshwater inputs, differential density layering and higher turbidity. The spatial and temporal fluctuations of these optical water types overlaid on changes in the bioluminescence potential make these areas uniquely complex. The development of an autonomous underwater vehicle with a bioluminescence capability allows measurements on sub-centimeter horizontal and vertical scales in shallow waters and provides the means to map the potential for detection of moving surface or subsurface objects. A deployment in San Diego Bay shows the influence of tides on the distribution of optical water types and the distribution of bioluminescent organisms. Here, these data are combined to comment on the potential for threat reduction in ports and harbors.
Diver visibility analyses and predictions, and water transparency in general, are of significant military and commercial interest. This is especially true in our current state, where ports and harbors are vulnerable to terrorist attacks from a variety of platforms both on and below the water (swimmers, divers, AUVs, ships, submarines, etc.). Aircraft hyperspectral imagery has been previously used successfully to classify coastal bottom types and map bathymetry and it is time to transition this observational tool to harbor and port security. Hyperspectral imagery is ideally suited for monitoring small-scale features and processes in these optically complex waters, because of its enhanced spectral (1-3 nm) and spatial (1-3 meters) resolutions. Under an existing NOAA project (CICORE), a field experiment was carried out (November 2004) in coordination with airborne hyperspectral ocean color overflights to develop methods and models for relating hyperspectral remote sensing reflectances to water transparency and diver visibility in San Pedro and San Diego Bays. These bays were focused areas because: (1) San Pedro harbor, with its ports of Los Angeles and Long Beach, is the busiest port in the U.S. and ranks 3rd in the world and (2) San Diego Harbor is one of the largest Naval ports, serving a diverse mix of commercial, recreational and military traffic, including more than 190 cruise ships annual. Maintaining harbor and port security has added complexity for these Southern California bays, because of the close proximity to the Mexican border. We will present in situ optical data and hyperspectral aircraft ocean color imagery from these two bays and compare and contrast the differences and similarities. This preliminary data will then be used to discuss how water transparency and diver visibility predictions improve harbor and port security.
Using a highly resolved LTER database collected near Palmer Station, Antarctica, from 1991-1994, the variability in the column photosynthetic cross section ((Psi) , m2, g Chl a-1) was analyzed. For the whole dataset, (Psi) had an average value of 0.0695 m2 g Chl a-1 but extreme values extended over a 50-fold range. A six-fold variation in (Psi) was observed with time of year and was strongly associated with the high seasonality in incident irradiance characteristic of these polar sampling sties. Variability in daily incident irradiance as influenced by cloudiness and variation in chlorophyll content were responsible for an additional two-fold variation in (Psi) . Finally, the taxonomic dependency of (Psi) was demonstrated for the first time. For identical chlorophyll content and surface irradiance, mean (Psi) value of 0.114 +/- 0.051 m2 g Chl a-1 were recorded for diatom blooms and 0.052 +/- 0.011 m2 g Chl a-1 for cryptophyte- dominated populations. Results illustrate the validity of (Psi) -based approaches for estimating primary production for the Southern Ocean but emphasize the need to address taxon- specific photophysiology to better estimate primary production on smaller spatio-temporal scales.
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