Rather sweet than salty: In the ocean microalgae produce a lot of sugar during algae blooms. These enormous quantities of algal biomass are normally recycled rapidly by marine bacteria – a degradation process that is an important part of the global carbon cycle. Especially sugars have been considered as easily digestible and therefore poor candidates for natural carbon sequestration. Now scientists from Bremen revealed: There exists a sugar in algae that resists rapid microbial degradation, accumulates, aggregates into particles and stores carbon during spring blooms. With this finding they show that this sugar can potentially act as an important carbon sink.