Linking Arsenic Biogeochemistry, Phosphorus Limitation, and Phytoplankton Dynamics in Oceanic Surface Waters
Jim Sanders, Skidaway Institute of Oceanography
30 Oct 2009
Arsenic (As) is a biologically reactive element, chemically quite similar to phosphorus. Its chemical form is highly variable in aquatic systems, with oxidized, reduced, and organic forms often present. The variability in chemical form of As is in response to the element's biological reactivity and its similarity to P; thus As cycling in aquatic systems is controlled to some extent by both the availability of P and the organisms present. Arsenic is also toxic, but differentially so, leading to potential changes in dominant phytoplankton species and species succession in systems, with potential for shifts in carbon and energy flow. During this seminar, I will review general aspects of As biogeochemistry, As-P coupling, and As cycling, and the interactions between As and phytoplankton and the potential for each to "regulate" the other, with particular attention to areas of the ocean with very low P concentrations.