Dinoflagellate cysts from the ‘Anthropocene’ of Gullmar Fjord, west coast of Sweden and their potential for monitoring climate change

Abstract

A small set of samples from Gullmar Fjord, on the west coast of Sweden, together with published data, has allowed the investigation of the ‘Anthropocene’ within the fjord. The dinoflagellate cyst record and its statistical analysis fails to show any marked changes within the assemblages either across the proposed boundary or indeed within the youngest sediments at the top of the sequence. However there are some small scale differences in the youngest assemblages that are of interest. In particular these include quantitative shifts in the numbers of some of the species especially Pentapharsodinium dalei, which may be indicative of somewhat cooler environments linked to the winter North Atlantic Oscillation (NAO) and extra availability of nutrients from Ekman pumping. These small scale shifts in the assemblages point to clear dynamism within the phytoplankton populations reacting to both anthropogenic and natural environmental change; evidence of the complexity of the system.The proven utility of dinoflagellate cysts in charting climate change throughout both the Pleistocene and Holocene within Gullmar Fjord, and elsewhere along the west coast of Sweden is in marked contrast to the little change at the ‘Anthropocene’ boundary. Nonetheless the geographical position of the fjords along the Skagerrak are ideal to monitor environmental change within the North Sea basin and perhaps further afield in the eastern North Atlantic Ocean; especially since further climate change threatens regime change within the marine environment affecting tourism, industry and mariculture along the coast.