Crude oil exposure reduces ice algal growth in a sea-ice mesocosm experiment

Oil production in Arctic ice-covered areas poses a risk for pollution of the ecosystem including that within brine channel network sea ice. Sea-ice autotrophs contribute substantially to primary production, but are inherently difficult test oil exposure responses situ. This study had two objectives, first, we developed suitable lab-based mesocosm system, second, tested effects on sea-ice algae. Specifically, investigated if Alaska North Slope crude reduces ice algal abundance, biomass and concentration extracellular polymeric substances (EPS) using indoor tanks over 10-day period. Six one cold room were used pairs following treatments: (1) control, (2) release as layer under (3) dispersed oil. All inoculated with microbial communities collected from Utqiaġvik, Alaska. After 10 days exposure, abundance algae, dominated by pennate diatom genus Nitzschia, concentrations EPS chlorophyll significantly lower oiled treatments compared control. We suggest light attenuation oil, reduced mobility, toxicity causes this reduction. Observed changes cell fluorescence characteristics based DNA staining could be linked provide new tool assessment microalgae.