Phytoplankton and zooplankton distribution along the Western Antarctic Peninsula: Implications for food web dynamics

 Montes-Hugo et al. (2009) and Mendes et al. (2013) found recent shifts in phytoplankton distribution associated with climatic variables; the former mapped abundance via satellite- Relative abundance derived chlorophyll concentrations Phytoplankton Chromatography sampling and chemical data for diatoms  Atkinson et al. (2004) noted increasing salp taxonomy and cryptophytes and decreasing krill stocks on a decadal scale

Laurence M. Gould A research cruise in January 2009 Inverse distance weighted (Antarctic summer) Points (vector) added by interpolation (raster) and Zooplankton Counting and Number per latitude and longitude for reclassification for each Sample calculation of additive (phytoplankton 3 sampling classification 1000 m data for phytoplankton ( ) and population to determine co-exclusion) and multiplicative (krill and diatom krill and salps zooplankton ( ) distribution patterns co-occurrence) map algebra for raster grids

B Zooplankton: Salps and krill exhibit co-exclusion trends  This project established distribution patterns Salps are more abundant Krill are more abundant in and correlations for populations whose in northern and offshore southern and onshore abundance is important to higher levels in the sites, and weakly co-occur sites, similar to diatoms Antarctic food web  Future work can investigate temporal Figure: (A) Inset map depicting the Western Antarctic changes, correlations with seabirds and Peninsula study area in pink. (B) Representative mammals, and potential driving of distribution Antarctic food web highlighting the lower trophic levels. by sea ice, temperature, salinity, or depth The foundation are phytoplankton; large diatoms are consumed by krill, and smaller cryptophytes are Cryptophytes and salps are Diatoms and krill are consumed by salps. Salps are a dead end in the web not strongly co-occurring somewhat co-occurring while krill offer nutrition for higher trophic levels. Shifting Atkinson, A., Siegel, V., Pakhomov, E., & Rothery, P. (2004). Long-term abundances and distributions at the lower levels have decline in krill stock and increase in salps within the Southern consequences for the entire food web. Ocean. Nature, 432(7013), 100-103. Mendes, C. R. B., Tavano, V. M., Leal, M. C., de Souza, M. S., Brotas, V., & Garcia, C. A. E. (2013). Shifts in the dominance between diatoms and cryptophytes during three late summers in the Bransfield Strait (Antarctic Peninsula). Polar biology, 36(4), 537-547. Montes-Hugo, M., Doney, S. C., Ducklow, H. W., Fraser, W., Martinson, D., Stammerjohn, S. E., & Schofield, O. (2009). Recent changes in Horizontal comparisons: populations phytoplankton communities associated with rapid regional climate change along the Western Antarctic Peninsula. Science, 323(5920), at the same level Phytoplankton: Cryptophytes and 1470-1473. Phytoplankton: Do cryptophytes and diatoms diatoms exhibit co-exclusion trends co-exclude each other? Zooplankton: Do salps and krill co-exclude each other? The Woods Hole The Palmer Long Term Oceanographic Institution Ecological Research Site including Scott Doney, team, especially principal Vertical comparisons: populations Maria Kavanaugh, and Hugh investigators Oscar Schofield and Ducklow for mentoring during my Debbie Steinberg for their High through the food web summer project, which then sparked Performance Liquid Chromatography my interest in extending my analyses and Zooplankton Density data tables Do diatoms and krill co-occur? to mapping with GIS from the summer 2009 cruise Do cryptophytes and salps co-occur? The Antarctic Digital The Tufts University GIS Database from the Scientific staff for their helpful Committee on Antarctic discussions during the Hypothesis Research for coast and sea polygons planning and execution of this project Horizontal comparisons will show segregation into areas of higher abundance and vertical Cryptophytes are more abundant Cartographer: María Ordovás-Montañés AS&E: Biology and Community Health comparisons will show areas with correlation in northern and onshore sites, GIS 101: Introduction to GIS | December 2014 between predator and prey and weakly co-occur Map Projection: WGS 1984 Antarctic Polar Stereographic