Diatoms in young sediments and net samples from the Kattegat

Core 14973, 590 cm long, retrieved from a depression at 130 m b.s.l. in the northeastern part of the Kattegat was analysed for its diatom content. The core material is assumed to have been deposited within the last 200 years. The diatom abundance (valves/g sed.) varied between 2 and 10 x 10 5 . The littoral Paralia sulcata was the predominant species. At 345 cm planktonic species dominated, with high percentages of Chaetoceros resting spores. Samples from 300 to 215 cm also had a fairly high planktonic element with Chaetoceros resting spores and Thalassiosira spp., especially T. angulata and T. eccentrica. The species composition compared well with records from the adjacent area, the Skagerrak, and from phytoplankton samples collected in the same area, although with a considerably larger proportion of benthic forms.