Ellen Oldenburg – Heinrich Heine University Düsseldorf, Germany
Timeseries analysis of Arctic pelagic bacterial and eukaryotic communities
Microbial communities as central elements of marine ecosystems show distinct spatiotemporal variability and harbor diverse interactions, shaped by environmental parameters. However, these dynamics in polar waters remain poorly understood, but are essential to characterize for assessing the fate of the future Arctic Ocean. In this study we analyze amplicon sequences of prokaryotes and eukaryotes autonomously collected over four years in the West Spitsbergen and East Greenland Currents within the FRAM long-term observatory and combine this with the MOSAiC project. MOSAiC started with the icebreaker Polarstern, which drifted with the sea ice over the central Arctic over one year. The aim of the this study is to perform an explanatory spatiotemporal analysis of eukaryotic and prokaryotic dynamics. Additional cooccurrence analysis and time series forecasts will allow us to describe community changing over time considering climate conditions. Beside the various descriptive analyses we analyze the time series components of each organism and their community. Ordering the abundance data by time shift allow us to characterize the appearance of each species over the year. We analyze the dynamic of prokaryotes and eukaryotes using Fourier transformation and regression analysis. This enables us to describe the individual time series components, such as seasonality and trend. Cooccurrence of species is described using a network approach based on similar species dynamics. Our results point to a fine tuned biological clock which is best described by an average temperature change of 2°C over the year. However, temperature explains only 60% of the variance. We identify daylight duration and eukaryotic/prokaryotic interaction as additional explanation variables. The integrated analyses of annual time series data will improve our overall understanding of the dynamics of the Arctic pelagic microbial community over the annual cycle. The narrow temperature range that enables species dynamics of primary producers and their consumers shows how sensitive the ecological system is to climate change. Comparison of species communities between the different locations revealed the uniqueness of the ecological niches.
This talk is part of the CyanoWorld online seminar series, hosted by Nicolas Schmelling and Ilka Axmann, and was held on Zoom on May 19th, 2022.
Follow Us on Twitter: https://twitter.com/CyanoWorld1