Seagrass appears to be a surprisingly sweet carbon sink. 

Sugar (sucrose) accumulates under seagrass meadows at concentrations that are around 80 times higher than previous marine records, according to new research. 

An international research team says their findings suggest seagrasses may represent a large global store of organic carbon because the plants produce compounds to hinder microbes that degrade the sugar, which would release carbon. 

The team analysed the chemistry of water from the sediment beneath three seagrass meadows around the world, finding high sucrose levels. 

Among the microbes living in the sediments, 80 per cent had genes for degrading sucrose, but these were only active in 64 per cent. 

The authors say low oxygen conditions in combination with compounds produced by the seagrasses known as phenolics may have hindered the activity of microbes, explaining why sugar has built up under these meadows.

The study is accessible here.