Dissertation Research: Quantifying the role of mixotrophic feeding in aquatic food webs

Suny College Of Environmental Science And Forestry, Syracuse NY

Investigators

Abstract

One of the basic tenets of aquatic ecology is that primary production by algae, through the process of photosynthesis, supports all aquatic food webs and is responsible for approximately half of the primary productivity on earth. In reality, many algal species are mixotrophic; that is, they are capable of supplementing photosynthetic production with heterotrophic consumption of bacteria, other algae, or even dissolved and particulate material transported into lakes from terrestrial sources. The proposed dissertation research will use natural stable isotopic tracers to quantify the amounts of algal production due to photosynthesis versus mixotrophy. Estimates of mixotrophy from laboratory and field experiments will be combined with predictive models of mixotroph abundance across the continental United States to evaluate the importance of mixotrophy in freshwater food webs. Mixotrophy represents a potentially important natural process that has been known for some time, but is poorly understood. Results from this study will allow more accurate descriptions and models of aquatic food webs. This knowledge will provide better predictions of changes to freshwater ecosystems - such as the occurrence of toxic algal blooms - that are increasingly exposed to human-induced modifications. The investigators will recruit undergraduates from under-served groups to participate in the research through ongoing SUNY-ESF programs. In addition, the research will be carried out at SUNY-ESF's Cranberry Lake Biological Station, which is an active teaching campus throughout the summer. Students enrolled in courses at the station will participate in the study.