Sponsored by: National Aeronautics and Space Administration
Project Period: October 1, 1997 – September 30, 2000
Principle Investigators: Michael J. Behrenfeld, Paul G. Falkowski, and Zbigniew Kolber

Achieving the goals of NASA’s Mission to Planet Earth regarding the role of the oceans in global biogeochemical cycles requires both fidelity in the estimation of net phytoplankton primary production and an established mechanism for generating comparable ocean productivity data products across successive generations of ocean color sensors.
Currently, only about half of the observed variability in depth-integrated primary production (IPP) can be accounted for by any productivity model and there is no organized procedure for establishing and updating a standard algorithm for generating productivity data products. This research project comprises both fundamental studies on phytoplankton photosynthesis and working group activities which specifically address these issues.
Basic research is being conducted to improve the characterization of the maximum rate of carbon fixation within the water column (Pbopt), the estimation of which is currently the greatest source of error in productivity model estimates of IPP. The physiological model for Pbopt is based on the assembly and analysis of a variable fluorescence database. Model parameterization emphasizes process oriented relationships and is based, to the greatest extent possible, on remotely sensed physical variables.

 

Our primary goal is to provide databases, algorithm structure and code, and an investigator-independent framework that permits continuity, validation, and quality assurance for primary production calculations into the 21st century.
For more information about this project, please visit our Ocean Primary Productivity Study, IMCS, Rutgers University web site.

Sponsored by NIH – General Medicine
Principle Investigator: Paul G. Falkowski

As large amounts of sequence information become available from the Human Genome Project, sequence analyses will provide clearer evidence that numerous human diseases or disorders have deep evolutionary roots. The project addresses the evolutionary origins of proteases and cell death responses as a case in point. Specifically, the research seeks to:

• examine to the evolutionary origins of autocatalyzed cell death associated with the stress induced expression of novel (cryptic) proteases in single-celled, asexual eucaryotes, specifically the obligate photoautotrophic chlorophyte alga, Dunaliella tertiolecta,
• elucidate the molecular triggers in physiological stress responses that lead to the induction of novel proteases and catastrophic cell death in such cells, and
• examine to what extent the cryptic proteases are ubiquitous in eucaryotes.

These goals address the biological significance of apoptosis and autocatalyzed cell death in the context of the evolution of somatic eucaryotes and the processes that repress or silence the expression of cryptic proteases encoded within their nuclear genomes.

In humans, protease-triggered apoptosis occurs in cytotoxic T lymphocytes and other defensive cell lines, but is also a symptom of numerous chronic diseases or disorders with little or no clear Mendalian genetic lineage. We hypothesize that the genes encoding the stress-induced proteases have been incorporated into bacterial and eukaryotic genomes from relic viral infections, comparable to the endogenous retroviral protease genes found in metazoans. These genes, normally silenced either by repressor factors or transpositions, appear to be derepressed when the organism is selectively stressed.

Sponsored by: National Science Foundation – Division of Ocean Sciences
Project Period: September 1, 2000 – August 31, 2005
Principle Investigators: Paul G. Falkowski, Kenneth Miller, Andrew Knoll, Oscar Schofield, Costantino Vetriani

Archived page for this project

NSF Collaborative Biocomplexity Proposal

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Dr. Paul Falkowski is the Lead Investigator for the NSF Biocomplexity grant researching phytoplankton evolution. The funding for this project began September 1, 2000 and will run through August 31, 2005.

We would like to share our proposed phytoplankton evolution research to those interested in this work (i.e., Post-doctoral scientists, graduate students, etc.). Thus, we are posting our Project Summary, Project Description, and Reference information for everyone to view. Please click on the appropriate section of your choice:

• Project Summary
• Project Description
• References

We would like to acknowledge the following participants in this Biocomplexity Project:

Senior Personnel: (PIs & Co-PIs)

Name	Institution	Telephone number	Email
Falkowski, Paul	IMCS, Rutgers	732-932-6555 ext. 370	falko@imcs.rutgers.edu
Miller, Kenneth	Geology, Rutgers	732-445-3622	kgm@rci.rutgers.edu
Vetriani, Costantino	IMCS, Rutgers	732-932-6555 ext. 373	vetriani@imcs.rutgers.edu
Schofield, Oscar	IMCS, Rutgers	732-932-6555 ext. 548	oscar@imcs.rutgers.edu
Wright, James	Geology, Rutgers	732-445-5722	jdwright@rci.rutgers.edu
Reinfelder, John	Env.Sci.,Rutgers	732-932-8013	reinfelder@envsci.rutgers.edu
Kent, Dennis	Geology, Rutgers	732-445-2044	dvk@rci.rutgers.edu
Miller, James	IMCS, Rutgers	732-932-6555 ext. 545	miller@arctic.rutgers.edu
Rosenthal, Yair	IMCS, Rutgers	732-932-6555 ext. 250	rosentha@imcs.rutgers.edu
Kerkhof, Lee	IMCS, Rutgers	732-932-6555 ext. 335	kerkhof@imcs.rutgers.edu
Kolber, Zbigniew	IMCS, Rutgers	732-932-6555 ext. 233	zkolber@imcs.rutgers.edu
Sherrell, Robert	IMCS, Rutgers	732-932-6555 ext. 252	sherrell@imcs.rutgers.edu
Iglesias, Debora	IMCS, Rutgers	+44-117-9287592	M.D.Iglesias-Rodriguez@bristol.ac.uk
Chen, Yibu	IMCS, Rutgers	732-932-3494	yibu@imcs.rutgers.edu
Frank, Ilana	IMCS, Rutgers	732-932-3497	irfrank@imcs.rutgers.edu
Bralower, Timothy	U. North Carolina	919-962-0704	bralower@email.unc.edu
Armstrong, Robert	SUNY – Stony Brook	631-632-3088	rarmstrong@notes.cc.sunysb.edu
Knoll, Andrew	Harvard Univ.	617-495-9306	aknoll@oeb.harvard.edu
Bissett, Paul	U. South Florida	813-837-3374 ext.102	paul@marine.usf.edu
Durnford, Dion	U. New Brunswick	506-452-6207	durnford@unb.ca
Gersonde, Rainer	Alfred Wegner Inst.		rgersonde@AWI-Bremerhaven.DE
Levin, Simon	Princeton U.	609-258-6880	simon@eno.Princeton.EDU
Medlin, Linda	Alfred Wegner Inst.	49-471-4831-1443	lmedlin@AWI-Bremerhaven.DE
Raven, John	U. Dundee	+44 (0)1382 344282	p.m.marshall@dundee.ac.uk
Smetacek, Victor	Alfred Wegner Inst.	+49 471 4831 440	vsmetacek@AWI-Bremerhaven.DE
Taylor, Max	U. British Columbia	604-822-4587	maxt@unixg.ubc.ca
Young, Jeremy	Museum of Nat. His.,UK	+44 (0)20 7942 5286	J.Young@nhm.ac.uk

Project Summary

The focus of this multidisciplinary research program is to understand the historical origins and environmental conditions that led to selection and radiation of the major eucaryotic phytoplankton taxa, and the ecological processes that contribute to their continued success in the contemporary ocean. The proposed research utilizes a combination of geological, molecular biological, ecological, and modeling approaches to address an important and complex puzzle in Earth system science. Our primary goal is to develop the first quantitative models of eucaryotic phytoplankton community structure in the contemporary oceans based on paleoecological and evolutionary inference. The central question raised in this proposal is: Why have three phylogenetically diverse groups of eucaryotic, unicellular algae been so ecologically successful and what does their evolutionary history tell us about the history of Earth and the ability of eucaryotic phytoplankton to accommodate to change in the future?

The proposed research seeks to test a set of three related hypotheses, from which we will develop a conceptual model for evolution and ecological success (dominance) of key phytoplankton taxa in the contemporary ocean. The central hypotheses are:

•  The three dominant phytoplankton taxa in the contemporary ocean evolved in shallow shelf-seas in the Mesozoic Era in response to changes in the ocean environment, such as anoxia, changes in sea level, or tectonic processes that excluded ecological advantages previously afforded to chlorophytes.
• Once established, these groups radiated rapidly. The rapid tempo of evolution was a consequence of high mutation frequencies relative to reversion and sexual recombination, resulting in high genetic potential and DNA content relative to genetic expression in the three taxa. The rapid tempo of evolution in the three taxa has permitted rapid radiation and adaptation to changing oceanic conditions throughout the Mesozoic. This rapid tempo continues to the present time.
• The ecological dominance of the three major eucaryotic phytoplankton taxa is a consequence of pan-division traits that permit individual species within each group to rapidly accommodate large variations in oceanic conditions. These traits include the evolution of cell walls and vacuoles that respectively provide protection from predation while simultaneously optimizing the exploitation of pulsed nutrient supplies. A corollary of this hypothesis is that the structure of marine food webs in the contemporary ocean is primarily a consequence of the tempo of evolution of the three major taxa of eucaryotic phytoplankton, which itself is a consequence of continuous changes in oceanic regimes.

This ambitious research program involves 27 Senior Research Scientists from 5 US universities, and includes 6 foreign collaborators: 3 from Germany, 1 from the UK and 2 from Canada. Our approach incorporates expertise from three groups of investigators, who were selected not only for their individual expertise, but because of their proven ability to work collaboratively. The three groups contain expertise in geology and geochemistry, molecular biology and biochemistry, and algal physiology and ecological modeling. The fundamental concept is to compare paleoecological data, inferred primarily from geological and geochemical proxies, with molecular biological and biochemical information to test hypotheses 1 and 2. The paleoecological data will serve to help guide physiological experiments and ecological models to test hypotheses 1 and 3. The research program contains three basic elements: (I) A geological/geochemical team focussing on reconstructing the paleoecology at key periods in the Mesozoic; (II) A molecular biology/biochemical team engaged in elucidating how paleoecological processes have selected specific phenotypic traits that led to the origin and subsequent tempo of evolution of the major groups, and (III) An experimental ecophysiology/modeling group that quantitatively evaluates how phenotypic traits relate to the ecological success of specific taxa in the historical and contemporary ocean. These three elements will be integrated across traditional disciplinary lines and will include coordinated field, laboratory and modeling efforts. Modeling efforts will be directed towards hindcasting and forecasting the success of key phytoplankton groups using observational and experimental information.

The research program is coupled to a strong educational effort, designed to provide a broad exposure and opportunity for undergraduate and graduate students, as well as a K-12 and teacher-training program designed to integrate Earth system science in primary and secondary school curricula.

SERDP Conservation SI-1334

Sponsored by: Strategic Environmental Research and Development Program (SERDP)
Principal Investigators: Maxim Gorbunov and Paul Falkowski

Background:

The U.S. Department of Defense (DoD) maintains numerous facilities in tropical and subtropical environments that are adjacent to coral reefs.  Coral reefs are specifically susceptible to anthropogenic insult and rapidly degrade worldwide.  The development of advanced technologies for environmental monitoring of benthic communities under DoD jurisdiction requires an understanding of how different environmental factors affect the key elements of the ecosystems and the selection of specific monitoring protocols that are most appropriate for the identification and quantification of particular stresses.  Documenting the environmental state of reef communities is critical to developing remediation strategies that can both reduce anthropogenic impact and distinguish between natural stress and anthropogenic factors potentially related to military activity.  The quantitative assessment of the impact of stresses requires the accurate knowledge of baseline biophysical, optical, and genetic parameters for “healthy” coral reef communities.  Due to natural variability within populations and diversity amongst species, these parameters vary both within and between species.

The Objectives of this SERDP project are

• to develop advanced techniques for rapid and non-destructive assessment of the viability and health of coral reef communities with the capabilities of identification and quantification of natural and anthropogenic stresses;
• to develop prototypes of Fluorescence Induction and Relaxation (FIRe) Fluorosensors for permanent underwater monitoring stations and Remote Operated Vehicles or Diver Propulsion Vehicles;
• to collect an extensive library of baseline data on physiological, biophysical, bio-optical and genetic diversity of coral reef communities near DoD installations.

Summary:

Rapid and non-destructive assessment of the health and viability of benthic photosynthetic organisms is based on the use of variable fluorescence technique.  This technique relies on the relationship between the efficiency of photosynthetic processes and chlorophyll fluorescence and derives a comprehensive suite of fluorescent and photosynthetic parameters of the target (Kolber et al. 1998; Gorbunov and Falkowski 2005).  In laboratory and field experiments, we study the impact of common natural stresses (elevated temperature, excess irradiance, and nutrient load), and selected anthropogenic stresses (like toxic pollutants) on the physiological status of coral.  Our results provide scientific background for the development of advanced protocols for non-destructive assessment of the health of coral reef ecosystems.  The molecular biology and genetic part of the project is focused on identification, as well as spectroscopic and genetic characterization of color proteins from corals.  This information will provide insight into the remarkable diversity of the color palette of reef corals, which is an important indicator of the health of coral reef ecosystems. The instrument development includes design and construction of advanced FIRe systems for permanent monitoring stations and autonomous vehicles.

References:

• Tchernov D, Gorbunov MY, de Vargas C, Yadav SN, Milligan AJ, Haggblom M, Falkowski PG. (2004) Membrane lipids of symbiotic algae are diagnostic of sensitivity to thermal bleaching in corals. – Proc. Nat. Acad. Sci., U.S.A., 101 (37): 13531-13535.
• Gorbunov MY, and Falkowski PG. (2005) Fluorescence Induction and Relaxation (FIRe) Technique and Instrumentation for Monitoring Photosynthetic Processes and Primary Production in Aquatic Ecosystems. In: “Photosynthesis: Fundamental Aspects to Global Perspectives” – Proc. 13th International Congress of Photosynthesis, Montreal, Aug.29 – Sept. 3, 2004. (Eds: A. van der Est and D. Bruce), Allen Press, V.2, pp. 1029-1031.

Sponsored by:  NASA – Instrument Incubator Program
Principle Investigators: Zbigniew Kolber and Paul Falkowski

This project seeks to develop an airborne Lidar-based system to measure photosynthetic performance and primary production in terrestrial ecosystems.The proposed method is based on measuring laser- induced fluorescence transients (LIFT) in response to a 50 millisecond excitation sequence at energy levels of 30 to 50 W/m². Specifically, this project seeks to:

• develop a Laser Induced Fluorescence Transient (LIFT) methodology to remotely assess photosynthetic performance from fluorescence transients induced by weak excitation light;
• proof and validate LIFT methodology in laboratory conditions;
• implement this methodology in a compact prototype instrument capable of airborne operation;
• field-test the LIFT method in relevant environmental conditions, operating from an airplane platform;
• specify the engineering design of the LIFT instrumentation for the next stage of Announcement Opportunity (AO) development.

The project proposes to excite chlorophyll fluorescence of the plant’s green tissue with a 50-millisecond-long excitation sequence of controlled intensity averaging 30 to 50 W/m². This will expose the photosynthetic reaction centers to about 20 quanta, causing up to 60% saturation of the photosynthetic electron transport and inducing transient changes in the chlorophyll fluorescence yield. The functional character of the measured fluorescence transient is controlled by the excitation signal and by a set of photosynthetic parameters, such as photosynthetic light utilization, the efficiency of photochemical conversion, and the rates of electron transport in photosystem II. All these parameters can be calculated by fitting the measured fluorescence transients into a mathematical model describing the relationship between photosynthesis and fluorescence. The project develops this model, determines the experimental protocols satisfying the optimal conditions for LIFT measurements under a limited signal-to-noise ratio, and conducts laboratory studies to verify this approach.

The proposed instrument uses a rectangular array of individually modulated laser beams to produce a wide excitation beam. Moving along a flight path with a typical speed of 135 mph (60 m/s), the beam “paints” a spatially modulated excitation image on the ground. This excitation pattern will, in turn, produce a fluorescence image, modulated spatially by the photosynthetic light utilization of exposed plants. The fluorescence image will be collected by a telescope and acquired by a red-sensitive microchannel plate image intensifier. Photosynthetic parameters will be calculated by fitting these two images into a numerical model describing the functional relationship between light, fluorescence, and photosynthesis. The same model will be used to calculate the rates of primary photochemistry.

The excitation beam are generated by an array of blue, blue-green, and red laser diodes. Commercial solid-state laser diodes in the red region (640-670 nm) of appropriate power rating are currently available. Blue, and blue-green solid-state laser diodes are at an earlier stage of development, and should become commercially available within the next 1-2 years. Using an array of laser diodes instead of standard Q-switched YAG lasers has several advantages: compact size and low power consumption; ability to generate an arbitrary excitation sequence; multiple-color excitation, and ability to generate a spatially modulated excitation pattern. The project also investigates an option of using a frequency-doubled YAG laser operating in a cw mode, equipped with a beam-expanding and beam-forming optics.

The project includes a field-test of the prototype instrument conducted in collaboration with the NASA’s Lidar group (Goddard Flight Space Center.) The results of these tests will specify design and performance requirements of the instrument that can be made mission-ready at the AO stage of the LIFT project. The system will comply with ANSI Z-136.1 guidelines on eye-safe laser radiation.