NRES Departmental Seminar by Dr. Sergiusz Czesny, Director, Lake Michigan Biological Station and Assistant Adjunct Professor in the Department of Natural Resources and Environmental Sciences (NRES) at the University of Illinois, Urbana-Champaign.

Title: Application of fatty acid analysis in aquatic ecology: Trophic tracers and essential nutrients

Chemical trophic tracers (fatty acids, stable isotopes etc.) are readily used in aquatic ecology to describe the structure of ecosystems and to better understand trophic interactions within food webs. Scientists reach for these tools to explore spatial and temporal trends in both species and trophic level interactions. From small streams to large lakes and oceans, trophic tracers allow ecologists to decipher resource partitioning and energy flow.

Application of fatty acid signature (FAS) analysis in food web ecology can provide additional insights because some fatty acids are known to be essential nutrients that can affect the physiological state of animals. Therefore quality rather than quantity of available food often becomes the limiting factor in trophic coupling as nutritional value of food can affect various physiological functions and contribute to reproductive success or cause suboptimal reproductive outcomes.

Within the Great Lakes, fish assemblages vary substantially as each ecosystem constitutes an inimitable community and has management strategies adapted to the particulars of its fisheries and conservation needs. Within each lake there are also considerable temporal fluctuations in the prey assemblage as native and nonnative species undergo sizable abundance oscillations. As a result, the nutrients available to top predators utilizing such a dynamic prey base should vary spatiotemporally and could affect their reproductive success.

Poster (PDF)

Speaker's website: http://www.inhs.uiuc.edu/staff/index.php?action=list&user_name=czesny.