Data on the heterotrophic bacterioplankton and concurrent environmental characteristics in the outer shelf and slope area of the Laptev Sea (Arctic Ocean)

In regions close to the continental shelf edge, the transfer of particulate organic carbon (POC) within the food web and with downward fluxes contributes to the long-term storage of carbon in deep basins. The degradation of POC by heterotrophic prokaryotes is one of the key indices of biological productivity and ecosystem functioning. Here we present data on the spatial and vertical distribution of the total bacterial abundance, fraction of high DNA-content and particle-associated bacteria, and POC concentration. Additionally we determined environmental parameters (temperature, salinity, turbidity, fluorescence and dissolved oxygen concentration). The data were collected in the Vilkitsky Strait and along two transects from the outer shelf of the Laptev Sea to the adjacent continental slope region of the Arctic Ocean in August−September 2018. Principal component analysis was used to reveal relationships between environmental factors and bacterial characteristics. Total bacterial abundance (BA) was positively correlated with seawater fluorescence, dissolved oxygen concentration and POC, but negatively linked to depth and salinity. The percentage of both particle-associated bacteria (%PAB) and bacteria with high DNA concentration (%HDNA) were positively linked to depth and salinity. The data obtained may be useful for a comprehensive assessment of the state of ecosystems in the vicinity of the Arctic continental slope under changing environmental conditions, as well as for studying microbial input in the carbon cycle.