You are here:
Does temperature structure phytoplankton community composition in the Ross Sea, Antarctica?
Citation:
Shields, A. R. Does temperature structure phytoplankton community composition in the Ross Sea, Antarctica? Presented at The American Society of Limnology and Oceanography Meeting, Orlando, FL, March 01 - 07, 2008.
Impact/Purpose:
Presentation at the American Society of Limnology and Oceanography Meeting
Description:
The Ross Sea polynya experiences one of the largest phytoplankton blooms in the Southern Ocean. Energy flow potential within the Ross Sea food web is primarily set by diatoms and prymnesiophytes, the latter dominated by Phaeocystis antarctica. We investigated physical, chemical, and biological factors that drive phytoplankton taxonomic composition and nutrient uptake in late austral spring. Principal components analysis (PCA) was performed on data from 2001-2005 including dissolved nutrients (N,P,Si), size fractionated chlorophyll, sample depth, BSi, POC, PON, temperature, and pigments. The temperature-based PC explained 13% of the variation in the data set, and further linear regressions were performed to assess the relationship between temperature and other biogeochemical variables. A significant relationship between increases in sea surface temperature and phytoplankton nitrate removal (R2=0.76, p<0.0001) was observed. Additionally, P. antarctica abundance appears to be favored under colder conditions while diatoms are abundant when surface temperatures are higher. Significant interannual differences in surface temperature were observed and are likely driven by changes in solar heating, stratification or by water mass intrusion, suggesting that physical processes may impact phytoplankton assemblage nutrient removal.