The oxygen fluxes of sandy littoral areas: Quantifying primary and secondary producers in the Baltic Sea

The study aimed to estimate the total oxygen flow through the shallow littoral of the Gulf of Gdańsk (southern Baltic Sea). Daily primary production and daily oxygen consumption by meso- and macroplankton and meio- and macrobenthos were measured, as well as the remaining (abiotic/microbial) oxygen consumption of the water column and bottom sediment. The daily gross primary production was 5.0 l of oxygen m−2, oxygen consumption was 9.2 l m−2, of which 16% were used by the water column and 84% by the bottom sediment. Abiotic oxygen consumption in water column contributed to less than 5% of the total oxygen consumption, and in the bottom sediment to 67%. Mesoplankton in the water column and meiobenthos in the bottom sediments were the major oxygen consumers in the littoral (67% and 26%, respectively).