Additionally to the ´biological pump´,the seasonal ´lipid pump´ is highly efficient at sequestering carbon into the deep ocean. It involves the vertical transport and metabolism of carbon rich lipids by overwintering zooplankton.
Every autumn across the North Atlantic, large numbers of zooplankton of the copepod species Calanus finmarchicus migrate from the surface waters into the ocean’s interior to hibernate at depths of 600–1,400 m. Through this migration, they actively transport lipid carbon to below the permanent thermocline, where it is metabolized at a rate comparable to the carbon delivered by sinking detritus. In other ocean basins, other species can be expected to fulfil similar roles as deep overwintering migrations of copepods are a common life strategy. This active transport of lipid carbon – the so-called lipid pump – has not been included in previous estimates of the deep-ocean carbon sequestration, which are based on either measurements of sinking fluxes of detritus, or estimates of new primary production. In particular, unlike other components of the biological pump, the lipid pump does not strip the surface ocean of nutrients, and decouples carbon sequestration from nutrient replenishment, a process we term the “lipid shunt.”
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Sigrún Huld Jónasdóttir, André W. Visser, Katherine Richardson, and Michael R. Heath, 2015. Seasonal copepod lipid pump promotes carbon. Proceedings of the National Academy of Sciences.
DOI: 10.1073/pnas.1512110112