T2-2.5 Critical seasonal windows of responses to multiple stressors on key organisms of benthic and pelagic food chains

Abstract

Due to climate change and pollution Arctic ecosystems are exposed to multiple stressors. Arctic ecosystems are highly seasonal and include substantial changes in the lipid composition of the organisms throughout the year. In periods with lipid mobilization many marine species will be prone to external stressors which may influence their ecology, physiology and biochemistry. These “critical periods of effects” (when energy stores are depleted and pollutants are remobilized from lipids to blood and other body organs) need to be determined in Arctic species belonging to the benthic and pelagic food chain. Key species in the benthic (amphipods, bivalves and common eiders) and pelagic (macrozooplankton, polar cod and kittiwakes) food web will be sampled throughout the year, with seabird data primarily from collaboration with ongoing and NPI lead work in breeding colonies. For fish and birds, organ specific distributions of pollutants and organ specific annual composition of fat, protein and energy will be quantified to determine their critical periods of effects in relation to time of year. From this, combined with habitat use and activity levels, critical periods of effects can be predicted.