Physiological Ecology of "Herbivorous" Antarctic Copepods

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Animals in the polar oceans have adapted to dramatic seasonal changes in day length, food availability, and ice cover, as well as to consistently cold waters. This project focuses on the adaptations of copepods - small animals that live in the water column and are an important food source to many different predators. The field studies will take place in the western Antarctic Peninsula, an environment and ecosystem that is rapidly changing. Antarctic copepods have developed particular feeding and behavioral strategies to survive in their very seasonal environment, however it is not known how each of these species will respond to environmental change. The overall goal of this project is to examine and compare these adaptations across species and to understand how each species responds to short-term changes in food availability. The project contains three main objectives: the first objective is to compare the sets of genes across species, especially looking at genes related to storage of energy from food. The second objective is to measure and compare the responses of copepods to changes in food availability. The third objective is to determine how variation across the western Antarctic Pensinsula habitat affects the feeding condition of the copepods. To make the data more useful to the broader research community, a database will be developed enabling easy comparison of genetic information between copepod species. This project will provide hands-on training opportunities to graduate and undergraduate student and will seek to recruit students from underrepresented groups. Results and scientific concepts will be shared through outreach activities, including an expedition blog, a series of interactive animations, and public presentations.Polar marine organisms have adapted to dramatic seasonal changes in photoperiod, light intensity, and ice cover, as well as to cold but stable thermal environments. The western Antarctic Peninsula, the focal region for the field studies, has experienced rapid warming and ice melt. While it is difficult to predict exactly how physical conditions in this region will change, effects on species distributions have already been documented. Large Antarctic copepods in the families Calanidae and Rhincalanidae are dominant components of the mesozooplankton that use different metabolic and behavioral strategies to optimize their use of a highly seasonal food supply. The overall goal of this project is to leverage molecular approaches to examine the physiological and metabolic adaptations at the individual and species level. The project focuses on three main objectives: the first objective is to characterize the gene complement and stage-specific gene expression patterns in Antarctic copepods within an evolutionary context. The second objective is to measure and compare the physiological and molecular responses of juvenile copepods to variable feeding conditions. The third objective is to characterize metabolic variation within natural copepod populations. The metabolically diverse Antarctic copepods also provide an excellent opportunity to compare mechanisms regulating energy storage and utilization and to test hypotheses regarding the roles of specific genes. The field studies will aim to utilize information from an ongoing long term research program (the Palmer Long-Term Ecological Research), which complements the ongoing program and provides extensive context for this project. To make the data more useful to the research community, a database will be developed facilitating comparison of transcriptomes between copepod species. This project will provide hands-on training opportunities to graduate and undergraduate students. Efforts will be made to recruit students who are members of underrepresented minorities. Results and scientific concepts will be broadly disseminated through an expedition blog, a series of interactive animations, and public presentations.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.