Veefkind, R. School of Earth and Ocean Sciences (SEOS), University of Victoria, Veefkind@uvic.ca
Whiticar, M. School of Earth and Ocean Sciences (SEOS), University of Victoria, Whiticar@uvic.ca
Perry, R. Pacific Biological Station (PBS), Department of Fisheries and Oceans (DFO), perryi@dfo-mpo.gc.ca
Whyte, J. Pacific Biological Station (PBS), Department of Fisheries and Oceans (DFO), whytei@DFO-MPO.gc.ca

 
THE STABLE CARBON ISOTOPE RATIO OF INDIVIDUAL FATTY ACIDS: A NOVEL TRACER IN MARINE FOOD WEB STUDIES?
 
The essential fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are important structural compounds in cell membranes of marine organisms. Synthesis of these compounds is limited in marine trophic levels higher than phytoplankton. Therefore an undisturbed transfer of EPA and DHA from phytoplankton to, e.g. fish, is likely. Furthermore, the stable carbon isotope ratio of these fatty acids (measured by Gas Chromatography - Isotopic Ratio Mass Spectrometry) should be similar in all organisms in the same food web. Difference in the 13C/12C values between bulk phytoplankton from bordering waters has been observed in other studies (Perry et al., submitted; Schell et al., 1998). Hence, by making use of the geographical divergence of 13C/12C at the base of the foodweb, our approach not only helps to delineate food web pathways, but potentially can also be used in fish movement and population dynamics studies. The presentation will present recent results from samples of particulate organic matter, zooplankton and fish, collected on multiple on-shelf to off-shelf transects off the West Coast of Vancouver Island. Similar single species samples taken at various stations will be compared and results of the analyses on fish tissues with different turnover rates will be discussed. References: Perry, R.I., Thompson, P.A., Mackas, D.L., Harrison, P.J. and Yelland, D. Submitted to Can. J. Fish. Aq. Sci. Schell, D.M., Barnett, B.A. and Vinette, K.A. (1998) Carbon and nitrogen isotope ratios in zooplankton of the Bering, Chukchi and Beaufort seas. Mar. Ecol. Prog. Ser. 162, 11-23.
 
Day: Thursday, Feb. 4
Time: 02:30 - 02:45pm
Location: Sweeney Center
 
Code: SS36TH0230S