Napolitano, G. E.. ,
Hayakawa, K. E.. Lake Biwa Research Institute,
Kumagai, M. Lake Biwa Research Institute,

The elucidation of trophic relationships and the identification of sources and sinks of biogenic carbon are important steps for understanding the dynamics of aquatic ecosystems. The analysis of trophic relationships between organisms can be investigated in a number of ways, from the simple inspection of gut contents, to the use of biochemical, immunological and stable isotope analyses. Certain lipids can be used to identify algal classes and to trace the transfer of biomass through the food chain, helping to define predator-prey relationships. Lipid markers can also indicate sources and sinks of discrete pools of biogenic carbon in different compartments of the ecosystem, including dissolved and particulate organic matter in the water column. We are investigating the viability of using fatty acid markers and signatures of Microcystis aeruginosa and other bloom forming phytoplankters of Lake Biwa to study their transfer to the planktonic and benthic grazers, and their eventual incorporation into the sediments. The initial study of the fatty acid compositions of cyanobacteria and microalgae from Lake Biwa, performed during experimental blooms and on natural samples, showed that Microcystis biomass can be distinguished from other bloom forming phytoplankters (i.e., Volvox sp. Uroglena americana and several species of diatoms), on the basis of their fatty acid signature. SS36 SS42 SS21 ORAL PRESENTATION
Day: Thursday, Feb. 4
Time: 02:45 - 03:00pm
Location: Sweeney Center
Code: SS36TH0245S