ACKNOWLEDGEMENTS

NEW SUBMERSIBLE ACTIVE FLUOROMETER USED TO MONITOR PHOTOSYNTHETIC PARAMETERS AND ALGAL BIOMASS

Dr. Raphael Kudela of the University of California at Santa Cruz and Dr. Erik Smith of the University of South Carolina

PHYTOFLASH SPECIFICATIONS

Turner Designs, Inc has developed an in situ variable fluorescence system that can be used to determine the quantum efficiency of phytoplankton in both oligotrophic and mesotrophic environments. The PhytoFlash (patent pending) is distinct from other ‘active’ fluorometers on the market in that it is the first solid-state instrument capable of variable fluorescence measurements on natural concentrations of phytoplankton. The solid-state platform allows for a much wider range of uses due to the small size, power efficiency, more stable components, and lower price point.

We would like to thank Dr. Raphael M. Kudela and Atma Roberts from the University of California at Santa Cruz, Dr. Erik Smith and Tracy Buck from the University of South Carolina’s Belle W. Baruch Institute for Marine and Coastal Sciences, Dr. Nick Welschmeyer from Moss Landing Marine Laboratories and his graduate students, Dr. Jacco Kromkamp from the Netherlands Institute of Ecology (NIOO-KNAW), and the USGS crew at Menlo Park, California.

Samples were collected at five sites during CTD profiles along a northern transect and tested on the PhytoFlash. The first graph presents a direct correlation between the Fo and extracted chlorophyll a. The second graph displays yields determined at each station. Phytoplankton samples comprised of mainly diatoms and dinoflagellates.

•The PhytoFlash is able to produce repeatable physiological parameters for freshwater and marine phytoplankton at low concentrations.

•The PhytoFlash is the first in situ,solid-state active fluorometer for use in natural waters.

•The PhytoFlash can be used for real-time data collection through the use of the internal data logger and battery pack or integrated into a CTD system.

•The PhytoFlash makes real-time, variable fluorescence measurements a reality for the research community.

Optical SpecificationsExcitation Filter <500 nmEmission Filter 680AF80 nmLED wavelength 460nm Minimum Detection Limit 0.15 µg/l

Electronic SpecificationsData Rate 230Hz Saturating LED duration 200-10,000 ms, 200ms (default)Data Format RS-232

Physical DimensionsLength 12 inches 30.5 cmWidth 3 inches 7.6 cmWeight (in air) 2.95 pounds 1.34 kgSample Volume 5.36 ml

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INTRODUCTION

Donovan, C. Turner Designs, Inc, Sunnyvale, California USA

Fo Minimum fluorescence Fm Maximum fluorescenceFv Variable fluroescence (Fm-Fo)Fv/Fm (yield) Maximum quantum yield of photochemistry in PSIIBlank Calculated blank value used in calibrationResponse Curves Available during laboratory mode

PHOTOSYNTHETIC PARAMETERS

The PhytoFlash can be integrated into a CTD or multi-parameter system, used in self-contained mode in conjunction with the internal data logger and attachable battery or in flow-through mode for laboratory work and in underway monitoring mode. The variable fluorescence measurement is being used in an ever-growing list of applications, such as;

•In situ measurement of phytoplankton photosynthetic parameters •Indicator of nutrient status of planktonic algae •Detection of the onset of algae blooms •Accurate measurement of algal biomass and monitoring algal community changes •Measurement of non-photochemical quenching (laboratory mode)•Ballast water monitoring

The PhytoFlash technique utilizes 3 low intensity LEDs to measure Fo and Fm and 6 high intensity LEDs to saturate cells in the sample chamber. The response curve from the saturating flash can be viewed in the laboratory mode. Unlike other ‘active’ fluorescence systems, the PhytoFlash does not provide induction curve data and is not designed as a physiological instrument for laboratory use. Rather, it is designed as a simplified and robust variable fluorescence system for submersible and/or laboratory use.

The PhytoFlash will provide the following parameters:

PERFORMANCE TESTING

CONCLUSIONS

Response Curves

Response curves and physiological parameters of Dunaliella salina and Skeletonema were determined using the Blue LED PhytoFlash.

IN SITU EXPERIMENTS

Minimum Detection LimitPhysiological ParametersDunaliella Skeletonema

Fo 5950 7450

Fm 17309 20273

Fv 11359 12823

Yield 0.656 0.642

USGS Hydrographic Stations in San Francisco Bay, California U.S.A

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FvFm Underway Mapping

The PhytoFlash was deployed as part of the NSF sponsored RISE program off the Oregon/Washington coast. Samples were collected from Niskin bottles, dark adapted for 30 minutes, and then run in laboratory mode. As expected there was a decrease in FvFm moving from onshore to offshore, and from surface to depth.

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http://online.sfsu.edu/~dhr/cimt/

United States Geological Survey South Bay Cruise in San Francisco Bay, California.

Long-Term Monitoring Site at North Inlet Winyah Bay National Estuarine Research Reserve, South Carolina.

The PhytoFlash was deployed at a depth of 0.5 m. An ISCO sampler was programmed to collect samples at two hour intervals. Samples were processed for extracted chlorophyll a, inorganic nutrients, and absorbance of filtered water samples.

1. Data reflecting absorbance, determined on a spectrofluorometer at 355nm, and water level over two tidal cycles (January 25, 2006). Absorbance is negatively correlated to water level, suggesting a strong export of colored fractionated water on the ebb tide.

2. Absorbance, water level, and PhytoFlash blank data were used a posteriori to “blank correct” for the PhytoFlash yields.

CDOM and Water Level

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Oyster Landing (OL) - (latitude 33o20'58" longitude 79o11'34")

The OL meteorological and water quality monitoring site, located at the end of the pier, is considered a fairly pristine and undisturbed area. The pier stretches into the upper reaches of Crabhaul Creek in the mid-western portion of North Inlet. The sampling site is located approximately 2.8km from the headwaters of Crabhaul Creek. The creek directly drains pine forested uplands and wetlands. Salinity can range from 0-32 ppt. and average tidal flux is approximately 1.4m.

The creek has an average depth of ~2m MHW and an average width of ~150m at MHW. The bottom is comprised mostly of oyster shell hash with some fine sediment and detritus. (http://www.northinlet.sc.edu/research/Default.htm#four%20sites)

http://www.google.com/lochp?hl=en&tab=wl&q=

North Inlet

Beta testing conducted by:

The PhytoFlash was integrated into the CIMT CTD January 2006 shipboard survey. Water samples were collected with Niskin bottles and processed for extracted chlorophyll a.

1. Data reflecting the correlation between Fo and Fm with extracted chlorophyll a. Calculated minimum detection limits (MDL) were 0.15 μg/l. MDL calculations were similar for Fo and Fm, suggesting yields are accurate at low chlorophyll a concentrations.

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y = 0.0005x + 0.1137

R2 = 0.8566

y = 0.0013x + 0.1715

R2 = 0.7789

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Coastal Ocean Projects Program/River Influences on Shelf Ecosystems Columbia River, Oregon/Washington