von Jackowski, Anabel , Grosse, Julia , Nöthig, Eva-Maria and Engel, Anja (2020) Dynamics of organic matter and bacterial activity in the Fram Strait during summer and autumn. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 378 (2181). Art.Nr. 20190366. DOI 10.1098/rsta.2019.0366.

Preview	Text Jackowski 2020.pdf - Published Version Available under License Creative Commons: Attribution 4.0. Download (990kB) | Preview
Preview	Text (Pressemitteilung) pm_2020_42_DOMArktis.pdf - Supplemental Material Available under License Creative Commons: Attribution 4.0. Download (115kB) | Preview
Preview	Text (Press release) pm_2020_42_DOMArktis_en.pdf - Supplemental Material Available under License Creative Commons: Attribution 4.0. Download (116kB) | Preview

Abstract

The Arctic Ocean is considerably affected by the consequences of global warming, including more extreme seasonal fluctuations in the physical environment. So far, little is known about seasonality in Arctic marine ecosystems in particular microbial dynamics and cycling of organic matter. The limited characterization can be partially attributed to logistic difficulties of sampling in the Arctic Ocean beyond the summer season. Here, we investigated the distribution and composition of dissolved organic matter (DOM), gel particles and heterotrophic bacterial activity in the Fram Strait during summer and autumn. Our results revealed that phytoplankton biomass influenced the concentration and composition of semi-labile dissolved organic carbon (DOC), which strongly decreased from summer to autumn. The seasonal decrease in bioavailability of DOM appeared to be the dominant control on bacterial abundance and activity, while no temperature effect was determined. Additionally, there were clear differences in transparent exopolymer particles (TEP) and Coomassie Blue stainable particles (CSP) dynamics. The amount of TEP and CSP decreased from summer to autumn, but CSP was relatively enriched in both seasons. Our study therewith indicates clear seasonal differences in the microbial cycling of organic matter in the Fram Strait. Our data may help to establish baseline knowledge about seasonal changes in microbial ecosystem dynamics to better assess the impact of environmental change in the warming Arctic Ocean.

Actions (login required)

View Item