The Chironomidae of Gróthúsvatn, Sandoy, Faroe Islands: climatic and lake-phosphorus reconstructions, and the impact of human settlement

Abstract

Chironomids were examined as part of a multiproxy palaeolimnological study of Gróthúsvatn, Sandoy, Faroe Islands. A total of 37 taxa was found in the top 1 m of the core. Chironomid-inferred total phosphorus and temperature reconstructions indicate that after landnám (the Norse settlement period) total phosphorus levels rose slightly, then peaked at a temperature minimum (interpreted as the `Little Ice Age'). Total phosphorus levels subsequently fell to only slightly above pre-settlement levels at the sediment surface. Little indication of increased erosion in the catchment after landnám was found, and it is likely that the impacts of human settlement on Gróthúsvatn and its catchment were slight. We therefore propose that the temperature decrease caused the increase in the lake's productivity.