Lipid content in overwintering Calanus finmarchicus across the Subpolar Eastern North Atlantic Ocean

The boreal copepod Calanus finmarchicus accumulates lipid reserves during summer feeding in surface ocean waters, which enable it to stay at depth and survive famine during overwintering. Respiration of lipids during prolonged overwintering at ocean depths (> 1000 m in some areas) has been shown to result in a net sequestration of carbon into the deep ocean: the so-called “lipid pump.” Here, we provide a comprehensive synthesis of the geographic and vertical variations in lipid content of overwintering animals across the Subpolar Eastern North Atlantic and, on the basis of this, we revise the estimates of carbon sequestration. Wax ester content ranged from 40 to 190 μg individual ⁻¹ at > 250 m depths, with highest concentrations in the coldest (< 0°C) waters at 400–600 m depth at the slope east of Faroe Islands and east of Greenland and lowest in the warmer (> 4°C) Irminger Sea and Rockall Basin. Our new analysis results in about 44% higher estimates of carbon sequestration at up to 11.5 g C m ⁻².