Autotroph-herbivore interactions in marine food webs are important to fisheries, the global carbon cycle, and, because of harmful algal blooms, human health. The recent hypothesis that harmful algae interfere with the growth and reproduction of zooplankton because of specific structural modifications of the algal sterols will be tested in research on the roles of nutritional factors in planktonic food webs. The effects of marine algal sterols on herbivorous crustaceans will be investigated in three calanoid copepods, Acartia hudsonica, Eurytemora affinis, and Calanus finmarchicus, and brine shrimp, Artemia salina. In this project, studies will be carried out to determine whether marine algal sterols can be metabolized to cholesterol by zooplankton and the relative efficiency of this process. This information is critical for assessing the nutritional value of different algal diets. Using the metabolic studies as a foundation, further experiments will seek to determine whether selected sterols, some of which have structural similarities to steroid hormones, have an inhibitory impact on the growth and reproduction of crustaceans. The analytical techniques used in these experiments will be high-field 13C-nuclear magnetic resonance spectrometry (NMR) and gas chromatography-high resolution mass spectrometry (GC-HRMS). Test sterols for these experiments will be labeled with stable isotopes (13C and 2H) in specific positions by chemical synthesis.
An important aspect of this project is the education and development of scientists. At SUNY-ESF, both doctoral and undergraduate students will benefit from research experience in bio-organic chemistry, while at Ohio University and Mount Desert Island Biological Laboratory, students will be trained in marine ecology. This interdisciplinary research will be educationally valuable and includes opportunities for the students from both groups to meet. Scientific infrastructure will be enhanced by a high sensitivity 13C-NMR probe requested for the 600 MHz NMR spectrometer, which is expected to benefit researchers at SUNY-ESF, as well as NMR users throughout the central New York state region. The scientific results will be published in peer reviewed journals and presented at conferences and seminars. The knowledge generated is expected to contribute to the enhanced understanding of marine ecosystems, and find application in aquaculture, the scientific study of fisheries and marine geochemistry.