TY - JOUR
T1 - A decade of microbial community dynamics on sinking particles during high carbon export events in the eastern Fram Strait
AU - Cardozo-Mino, Magda G.
AU - Salter, Ian
AU - Nöthig, Eva-Maria
AU - Metfies, Katja
AU - Ramondenc, Simon
AU - Wekerle, Claudia
AU - Krumpen, Thomas
AU - Boetius, Antje
AU - Bienhold, Christina
PY - 2023/7/11
Y1 - 2023/7/11
N2 - Marine sinking particles sequester atmospheric carbon dioxide to the deep ocean via the biological carbon pump. Understanding how environmental shifts drive changes in the microbial composition of particles, and how these affect the export of organic matter from the surface to the deep ocean, is critical, especially in the rapidly changing Arctic Ocean. Here, we applied next generation sequencing of the 18S and 16S rRNA genes to sediment trap samples from around 200 m water depth in the eastern Fram Strait, covering a time frame of more than one decade (2000-2012). The aim was to characterize their microbial composition during annual highest particulate organic carbon flux events. The bimodal annual spring and summer export fluxes were representative of the strong seasonality in the region. Furthermore, the study period was characterized by considerable interannual variation, marked especially by a warm water anomaly between 2005 and 2007. During this period changes in the hydrography and sea ice cover also led to measurable changes in the microbial composition of particles. The warm water period was marked by a decrease in diatoms affiliated with Chaetoceros, an increase of small phytoplankton and an increase in sequence abundance of the bacterial taxa Oceanospirillales, Alteromonadales and Rhodobacterales on the particles. The resulting changes in microbial composition and the associated microbial network structure suggest the emergence of a more developed retention system in the surface ocean. Our results provide the first long-term assessment of the microbial composition of sinking particles in the Arctic Ocean, and stress the importance of sea ice and hydrography for particle composition and subsequent flux of organic matter to deeper waters.
AB - Marine sinking particles sequester atmospheric carbon dioxide to the deep ocean via the biological carbon pump. Understanding how environmental shifts drive changes in the microbial composition of particles, and how these affect the export of organic matter from the surface to the deep ocean, is critical, especially in the rapidly changing Arctic Ocean. Here, we applied next generation sequencing of the 18S and 16S rRNA genes to sediment trap samples from around 200 m water depth in the eastern Fram Strait, covering a time frame of more than one decade (2000-2012). The aim was to characterize their microbial composition during annual highest particulate organic carbon flux events. The bimodal annual spring and summer export fluxes were representative of the strong seasonality in the region. Furthermore, the study period was characterized by considerable interannual variation, marked especially by a warm water anomaly between 2005 and 2007. During this period changes in the hydrography and sea ice cover also led to measurable changes in the microbial composition of particles. The warm water period was marked by a decrease in diatoms affiliated with Chaetoceros, an increase of small phytoplankton and an increase in sequence abundance of the bacterial taxa Oceanospirillales, Alteromonadales and Rhodobacterales on the particles. The resulting changes in microbial composition and the associated microbial network structure suggest the emergence of a more developed retention system in the surface ocean. Our results provide the first long-term assessment of the microbial composition of sinking particles in the Arctic Ocean, and stress the importance of sea ice and hydrography for particle composition and subsequent flux of organic matter to deeper waters.
KW - Sediment trap
KW - Fram Strait
KW - Arctic
KW - Pelagic-Benthic coupling
KW - Environmental DNA
KW - Sea-ice
KW - Carbon sequestration
KW - Biological carbon pump
KW - Autonomous Sampling
KW - Time-series
UR - http://dx.doi.org/10.3389/fmars.2023.1173384
U2 - 10.3389/fmars.2023.1173384
DO - 10.3389/fmars.2023.1173384
M3 - Article
SN - 2296-7745
VL - 10
SP - 1
EP - 22
JO - Frontiers in Marine Science
JF - Frontiers in Marine Science
M1 - 1173384
ER -