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Projects: Using Fluorescence Induction to Study Phytoplankton |
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Measuring the health of phytoplankton using Webb gliders
Development of fluorescent induction and relaxation systems for the measurement of biomass and primary productivity on Webb Slocum gliders
Funding Agency: NOAA’s Office of Ocean Exploration
Project Dates: October 1, 2006 to September 30, 2009
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COOL Examples |
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The ability to map the concentration and productivity of phytoplankton is a key to understanding the biogeochemistry of Earth. While great progress has been made to in mapping the concentration of the phytoplankton using ocean color techniques, the ability to measure rate processes remains difficult. Our group has been developing new platforms (cables & robots) for exploring the world’s oceans. As these technologies represent the future of ocean exploration and new sensors must be developed for these platforms. The buoyancy driven gliders represent the most challenging platforms as these systems require small sensors that have minimal power requirements. Therefore the goal of this project is to develop a new sensor that can measure the health of the phytoplankton with a sensor capable of being carried on a Webb Slocum glider.
Over the last decade, chlorophyll fluorescence measurements have provided unprecedented insights into the factors controlling phytoplankton physiology and primary production in the ocean. The technique relies on active stimulation and detection of the induction and subsequent relaxation of chlorophyll fluorescence yields on micro- and millisecond time scales. Analysis of the induced variable fluorescence provides a comprehensive suite of fluorescent and photosynthetic parameters of the phytoplankton. From these, a detailed picture of photosynthetic status can be deduced. The measured parameters provide the basis to model gross primary productivity and assess the impact of environmental stresses. This project will build a miniature Fluorescence Induction and Relaxation (FIRe) System for Webb Gliders. This project will demonstrate the FIRe mounted on a Webb Glider.
Our results to date:
- The prototype FIRe have been constructed. It will be mounted into a Glider. The initial deployment is currently scheduled for August 2008.
- To improve Glider power capabilities, a new lithium payload was developed and tested by flying a glider from New Jersey to Halifax Canada. The blog of the deployment can be found at http://blog.i-cool.org/.
- The prototype FIRe will be used to study the physiology of phytoplankton during the Fall and Winter in the Mid-Atlantic Bight. The goal will be to assess the impact of large storms on the health of phytoplankton.
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 An example of the FIRe measurement protocol consisting of four phases: 1. a strong short pulse of 100 µs duration (called Single Turnover Flash, STF) is applied to cumulatively saturate PSII and measure the fluorescence induction from Fo to Fm(STF);
2. weak modulated light is applied to record the relaxation kinetics of fluorescence yield on the time scale of 500 ms;
3. a strong long pulse of 50 ms duration (called Multiple Turnover Flash, MTF) is applied to saturate PSII and the PQ pool;
4. weak modulated light is applied to record the kinetics of the PQ pool re-oxidation the time scale of 1s
 The prototype FIRe system for the Glider. Visible is the blue excitation light.
 The flight path of the lithium Webb Glider.
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Oscar Schofield
RU COOL
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Scott Glenn
RU COOL
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Clayton Jones
Webb Research
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Scott MaClean
Satlantic Inc.
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Historical references
- Falkowski, P. G. & Raven, J. A. 2007. Aquatic Photosynthesis. Blackwell Scientific Publishers, Oxford, 375
Behrenfeld, M. J., and Z. S. Kolber. 1999 Widespread iron limitation in the South Pacific Science. 283, 840-843. [Reprint Copy - PDF ]
- Gorbunov, M.Y., Z.S. Kolber and P.G. Falkowski. 1999. Measuring photosynthetic parameters in individual algal cells by Fast Repetition Rate Fluorometry. Photosyn. Res. 62: 141-153. [Reprint Copy – PDF ]
- Kolber, Z. S., O. Prasil, and P. G. Falkowski. Measurements of variable chlorophyll fluorescence using fast repetition rate techniques. I. Defining methodology and experimental protocols. 1998. Biochem. Biophys. Acta 1367, 88-106. [Reprint Copy - PDF ]
Progress Report
Additional Information
The duration of the flight to Halifax: here >>
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