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

Abstract

Melles, M. 2001 (September): A Holocene seabird record from Raf es Sø sediments, East Greenland, in response to climatic and oceanic changes. Boreas, Vol. 30, pp. 228-239. Oslo. ISSN 0300-9483.A 3.5-m-long sediment sequence from a lake on Raf es Ø, off Liverpool Land, East Greenland, was investigated for chronology, lithology, palynology and biogeochemistry. Radiocarbon-dating of plant remains and the lithology of the sediment succession indicate continuous sedimentation since deglaciation of the area prior to 10 000 cal. yr BP. The postglacial palynological record shows little variation and evidence of a wind-transported pollen supply, both resulting from the geographical characteristics of Raf es Ø. Signi cant variations in the biogeochemical data re ect changes in aquatic bioproduction. These changes depend to some extent on climatic changes; however, they are mainly due to variations in seabird breeding colonies in the catchment which in uence nutrient and cadmium supply to the lake. Large seabird breeding colonies 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 es Ø caused by a too dense or too open seaice cover. In contrast, between 1900 and 1000 and from 500 to 100 cal. yr BP, the seabird settlement was probably restricted by an insuf ciently long breeding season due to cold climate conditions in East Greenland.

Lake sediments from Store Koldewey, Northeast Greenland, as archive of Late Pleistocene and Holocene climatic and environmental changes

“…7), most likely represent phases of high productivity during periods of warmer summers. Two warm peaks separated by a cold interval around 1 kyr BP have been registered in other records from East and Northeast Greenland (Wagner et al 2000; Wagner & Melles 2001). Distinctly lower chironomid concentrations in the late Holocene might be influenced by frequent changes of temperatures.…”

“…This Holocene temperature pattern is also recorded in deltaic sedimentary records and several lake sediment sequences (Wagner et al 2000; Christiansen et al 2002; Wagner & Melles 2002; Wagner et al 2005). Most of the former studies on lake sediments used pollen or biogeochemical proxies (Funder 1978, 1979; Björck et al 1994a, b; Fredskild 1995; Wagner et al 2000; Wagner & Melles 2001, 2002). Chironomid larvae are the most abundant insects found in freshwater lakes (Cranston 1995) and preserve well as fossils in lake sediments.…”

Quantitative relationships between benthic diatom assemblages and water chemistry in Macquarie Island lakes and their potential for reconstructing past environmental changes

“…Similar work has been undertaken on Signy Island where seal hairs were used to track an expanding seal population following the decline and cessation of the whaling industry (Hodgson & Johnston 1997) and on King George Island and Hope Bay where faecally derived elements have been used to track changes in penguin populations (Zale 1994, Sun et al 2000. In the northern high latitudes, changes in nutrient inputs to lakes have been used to track the impact of changing seabird populations (Wagner & Melles 2001). A similar approach could be used to reconstruct past animal populations on Macquarie Island.…”

A Regional Approach to the Medieval Warm Period and the Little Ice Age

“…Greenland has been the subject of palaeoclimatological research efforts for several decades, resulting among other things in a number of well-known δ 18 O ice-core records (Andersen et al, 2006;Dansgaard et al, 1975). In the last decades, marine sediment cores from Greenland's extensive coastlines as well as lake sediment cores from the ice-free coastal areas have also become available (Andresen et al, 2004;Cremer et al, 2001;Moros et al 2006;Møller et al, 2006;Roncaglia and Kuijpers, 2004;Seidenkrantz et al, 2007;Wagner and Melles, 2001). Most of the sediment records unfortunately have too low a temporal resolution and/or too large uncertainties in the dating to be useful in a quantitative multiproxy temperature reconstruction aimed at being calibrated to temperature values.…”