Seasonality of microbial genetic functions in the Arctic Ocean revealed by autonomous sampling
The functional diversity of microbes along the seasonal extremes in the Arctic Ocean including the Polar Night are virtually unknown. Here, using PacBio long-read metagenomes derived from automated samplers over an annual cycle, we elucidate functional microbial seasonality in the Fram Strait in the context of a high-resolution amplicon time-series. In the ice-free West Spitsbergen Current, the transition from the phototrophy-dominated spring and summer ecosystem states to the dark winter was evident in bacterial genomes. Proteorhodopsin- and DMSP-utilizing genes peaked in late summer, marking a transition phase. Winter mixing of the water column covaried with microbial taxa encoding ammonia- and urea-metabolizing genes, with probable implications for nitrogen recycling and the following phytoplankton bloom. In the ice-covered East Greenland Current, functional diversity varied with the extent of ice cover and polar water masses. During intermittent low-ice conditions in winter, the metagenomic repertoire resembled that during summer, indicating rapidly (i.e. within weeks) shifting ecosystem states with ice cover. Overall, we provide a baseline to understand ecological and biogeochemical processes in a region severely affected by climate change, with implications for the present and future Arctic Ocean.
Helmholtz Research Programs > CHANGING EARTH (2021-2027) > PT6:Marine and Polar Life: Sustaining Biodiversity, Biotic Interactions, Biogeochemical Functions > ST6.2: Adaptation of marine life: from genes to ecosystems
Helmholtz Research Programs > CHANGING EARTH (2021-2027) > PT6:Marine and Polar Life: Sustaining Biodiversity, Biotic Interactions, Biogeochemical Functions > ST6.3: The future biological carbon pump
Ocean-based Stations > Hausgarten Observatory
Vessels > Polarstern
PS > 114
PS > 121
PS > 126/1
PS > 99