Can fatty acids improve our ability to trace food web processes?

Over the next 3 years a team of investigators at SUNY ESF will be trying to answer this question.  Read on to learn more!

NSF-Funded Project Summary

Essential fatty acids are synthesized by primary producers; herbivores and predators must obtain these biochemicals from their diet.  Interest in the vital nutritional role of essential fatty acids has surged in the past decade, meriting attention in such diverse fields as agriculture, aquaculture, and medical science, and the human health benefits of essential polyunsaturated fatty acids (‘fish oils’) have made headlines in the popular press.  Several essential polyunsaturated fatty acids, such as EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) are associated with both phospholipids of biomembranes and hormone precursors, and thus are involved in many physiological processes including neurological function.

Although the importance of fatty acids in nutrition of organisms such as zooplankton and fish is the focus of current research, the potential influence of fatty acids on community and ecosystem ecology is relatively understudied.  Many suggestive ecological studies on essential fatty acids have relied on uncontrolled field correlations.  We propose several sets of controlled experiments utilizing a model aquatic food web to investigate two potential ways the study of essential fatty acids may improve our understanding of food web processes.

First, food rich in essential fatty acids appears to be of high food quality, i.e., it promotes higher growth of some consumers.  Per unit carbon or energy, a food web dominated by primary producers that have a high fatty acid content may thus have a higher trophic transfer efficiency than a system dominated by primary producers low in these essential compounds.  Further, a consumer eating a mixed diet may derive a disproportionate amount of its growth potential from a small diet component that is rich in essential fatty acids.  Including essential fatty acid composition as a component of food quality will allow ecologists better to predict trophic transfer efficiency and identify nutritionally crucial food resources that may previously have been overlooked.

Second, it has been proposed that the conservation of essential fatty acids from food to consumer may allow the relative abundances of particular fatty acids to be used as a tracer of diet.  Although several studies have documented similar fatty acid composition between food source and consumer, there have been no rigorous tests of the potential limitations of using fatty acids as food web tracers, especially under realistic mixed diet scenarios.

The proposed experiments will quantify both trophic transfer efficiency and food-consumer fatty acid similarity across three trophic levels:  from four different algal primary producers, to both selective and non-selective herbivores, and finally to predators.  Experiments will be performed both with uniform and mixed diets.  The concentration of several essential fatty acids will be manipulated independently of algal taxon, to allow isolation of fatty acid effects.

Principle Investigators

Mark Teece	Kim Schulz
SUNY ESF, Environmental Chemistry  http://www.esf.edu/chemistry/faculty/teece.htm	SUNY ESF, Environmental and Forest Biology  http://www.esf.edu/efb/faculty/schulz.htm

Co-PIs

Karin Limburg	John Farrell
SUNY ESF, Environmental and Forest Biology http://www.esf.edu/efb/faculty/limburg.htm	SUNY ESF, Environmental and Forest Biology http://www.esf.edu/efb/faculty/farrell.htm

Project Opportunities

Student Opportunities -- Ecology and Biochemistry Research Assistantships
Two fellowships are available for PhD (preferred) or MS students interested in working at the boundary of ecology and biochemistry on a NSF-funded project at the State University of New York’s College of Environmental Science and Forestry in Syracuse, New York (www.esf.edu). 

Students will develop dissertations which will examine the role of essential fatty acids in aquatic food webs.  Specifically research will focus on the effects of fatty acids on trophic transfer efficiency from phytoplankton to fish, their potential use as tracers of diet, and the possibility for biosynthesis of these ‘essential’ compounds by consumers. 

Successful applicants will receive 12 month Research Assistantships with tuition waivers, and interdisciplinary training in both ecology (aquatic culture techniques, nutrient chemistry, food web analysis) and biochemistry (fatty acid analysis, stable isotope techniques).  The project will involve both laboratory and field work.  Fellowships are available beginning either winter or summer 2006.

Interested individuals should contact either:

Kimberly Schulz                                                           OR       Mark Teece
Environmental and Forest Biology                                             Environmental Chemistry
SUNY ESF                                                                              SUNY ESF
kschulz@syr.edu                                                                      mteece@esf.edu
(315) 470-6808                                                                       (315) 470-4736

The Research Foundation of the State University of New York is an Equal Opportunity/Affirmative Action employer. All qualified applicants will receive consideration for employment without regard to their race, color, religion, national origin, age, disability, veteran status, marital status, sexual orientation, or sex, except where sex is a bona fide occupational qualification.

SUNY ESF specializes in environmental science and renewable resource programs, and combines the best qualities of a small college (1,600 undergraduates and 600 graduate students) and a research intensive doctoral-degree granting institution; its academic campus is located in Syracuse N.Y. on the campus of Syracuse University, and it has over 25,000 acres of field stations and regional campuses across New York State.  Syracuse is within easy driving distance of Lake Ontario, the Finger Lakes, and the Adirondack Mountains, with many local outdoor recreational opportunities including skiing, snowboarding, hiking and canoeing.

For more information contact either Kim Schulz (kschulz@syr.edu) or Mark Teece (mteece@esf.edu)
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