Siliceous microfossil data (diatoms) from the western Gotland Basin, Baltic Sea, covering the last 1200 years

Elinor Andrén, Thomas Andrén

This dataset consists of siliceous microfossil counts (mainly diatoms) and concentration (absolute abundance), from a 233 cm long splice sediment record (core MSM62-1-60) from the western Gotland Basin, Baltic Sea, at a water depth of 203 to 218 m. The sediment was collected in March 2017 and covers approximately 1200 years (2017⁠ – ⁠756 CE).

Siliceous microfossil data are used to provide information on e.g. changes in primary production, stratification, bloom seasonality and surface water salinity conditions.

This dataset was used to compare the environmental conditions reconstructed during Medieval times with settings occurring the last century under influence of environmental stressors like eutrophication and climate change.

Citation

Elinor Andrén, Thomas Andrén (2020) Siliceous microfossil data (diatoms) from the western Gotland Basin, Baltic Sea, covering the last 1200 years. Dataset version 1. Bolin Centre Database. https://doi.org/10.17043/andren-2020-diatoms-1

References

Andrén E, van Wirdum F, Norbäck Ivarsson L, Lönn M, Moros M, Andrén T (2020). Medieval versus recent environmental conditions in the Baltic Proper, what was different a thousand years ago? Palaeogeography, Palaeoclimatology, Palaeoecology 555, 109878. https://doi.org/10.1016/j.palaeo.2020.109878

Data description

The dataset contains diatom species data (counts) and siliceous microfossil absolute abundance (concentration) data from 60 stratigraphical levels covering 2017⁠ – ⁠756 CE (~1200 years) from a 233 cm long splice sediment record (core MSM62-1-60). Sediment depth (cm below sea floor) and ages (years CE) are provided.

The data are provided in one xlsx spreadsheet file having two data tabs. The same data are also provided as two comma-separated values (csv) text files. Character set: Unicode (UTF-8).

Comments

Position of corers

• long gravity corer: 57° 58.64’ N, 17° 57.37’ E, water depth 218.6 m
• short multicorer: 57° 58.73’ N, 17° 57.56’ E, water depth 203 m

Elinor Andrén developed the microfossil data. Thomas Andrén developed the age model.

For information on age modelling see article by Andrén et al. (2020).

The sediment samples were prepared for siliceous microfossil analyses according to the method described in Battarbee (1986) and Battarbee and Kneen (1982). All concentrations are given in number per gram dry weight (No./gdw). The floras used for diatom identification and classification into salinity requirements and life form (pelagic versus benthic) are Cleve-Euler (1951⁠ – ⁠1955), Hasle and Syvertsen (1997), Krammer and Lange-Bertalot (1986⁠ – ⁠1991), Snoeijs et al. (1993⁠ – ⁠1998) and Witkowski et al. (2000), and taxonomic names are updated according to AlgaeBase. All references and details of methods can be found in Andrén et al. (2020).