A Holocene seabird record from Raffles So sediments, East Greenland, in response to climatic and oceanic changes

A 3.5-m-long sediment sequence from a lake on Raffles empty set. off Liverp ool Land. East Greenland. was investigated for chronology. lithology. palyn ology and biogeochemistry. Radiocarbon-dating of plant remains and the lith ology,, of the sediment succession indicate continuous sedimentation since deglaciation of the area prior to 10 000 cal. yr BP. The postglacial palyno logical record shows little variation and evidence of a wind-transported po llen supply. both resulting from the geographical characteristics of Raffle s empty set. Significant variations in the biogeochemical data reflect chan ges in aquatic bioproduction. These changes depend to some extent on climat ic changes; however. they are mainly due to variations in seabird breeding colonies in the catchment which influence nutrient and cadmium Supply to th e lake. Large seabird breeding colonic, were present between 7500 and 1900, from 1000 to 500. and since c. 100 cal. yr BP. Their absence prior to 7500 cal. yr BP may be the result Of unsuitable feeding conditions close to Raf fles empty set caused by a too dense or too open sea-ice cover, In contrast . between 1900 and 1000 and from 500 to 100 cal. vr B.P. the seabird settle ment was probably restricted by an insufficiently long breeding season due to cold climate conditions in East Greenland.