Biological Pump Influence on the Persistent Organic Pollutants Biogeochemistry in Pristine Environments

Persistent organic pollutants (POPs) reach Antarctica through atmospheric transport, oceanic currents, and to minor extent, by migratory animals. The Southern Ocean is a net sink for many POPs with a key contribution of the settling fluxes of POPs sorbed to organic matter (biological pump) to this sink. However, little is known about POP transfer through the food web in the Southern Ocean, where krill is an important ecological node. In the present project we will meassure the concentration of POPs (PCBs, HCHs and HCB) in several environmental matrices to test the influence of the POPs Biological Pump sinking fluxes on the transfer of POPs trough the food web. The rationale of the project is that, during high productivity periods, POPs are effectively transferred to sediments due to high sedimentation fluxes compared to tbiomagnification of POPs to Krill and in consequence to higher trophic levels. Due to this, exportation fluxes to deeper waters will prevent or reduce the biomagnification of POPs trough the food-web. To tackle this we propose to sample air, water, sinking particles, phytoplankton and zooplankton during a short time serie (2 months) in highly to moderate productive areas in Antarctica. The present project will cover all the POPs Biogeochemical processes occurring between the air, water, sediments and biota. Allowing to estimate the magnitude of POP fluxes trough the food chain and the POPs biological pump sinking fluxes. By estimating these fluxes we could elucidate if the biological pump is preventing the POPs transfer trough the food web during high productivity periods.