Publication Date:
2021-10-20
Description:
Coastal sands are biocatalytic filters for dissolved and particulate organic matter of marine and terrestrial origin, thus, acting as
centers of organic matter transformation. At high temporal resolution, we accessed the variability of benthic bacterial communities
over two annual cycles at Helgoland (North Sea), and compared it with seasonality of communities in Isfjorden (Svalbard, 78°N)
sediments, where primary production does not occur during winter. Benthic community structure remained stable in both,
temperate and polar sediments on the level of cell counts and 16S rRNA-based taxonomy. Actinobacteriota of uncultured
Actinomarinales and Microtrichales were a major group, with 8 ± 1% of total reads (Helgoland) and 31 ± 6% (Svalbard). Their high
activity (frequency of dividing cells 28%) and in situ cell numbers of 〉10% of total microbes in Svalbard sediments, suggest
Actinomarinales and Microtrichales as key heterotrophs for carbon mineralization. Even though Helgoland and Svalbard sampling
sites showed no phytodetritus-driven changes of the benthic bacterial community structure, they harbored significantly different
communities (p 〈 0.0001, r = 0.963). The temporal stability of benthic bacterial communities is in stark contrast to the dynamic
succession typical of coastal waters, suggesting that pelagic and benthic bacterial communities respond to phytoplankton
productivity very differently.
Repository Name:
EPIC Alfred Wegener Institut
Type:
Article
,
isiRev
Format:
application/pdf
