Greening the high Arctic : When and how have seabirds transformed the fresh waters of the NOW Polynya?
The North Water Polynya (NOW) is host to an exceptionally large number of seabirds, which gather in large colonies over the brief summer months. These birds link marine and terrestrial ecosystems as they rely on the productivity of the marine polynya for their sustenance but use the terrestrial envi...
| Main Authors: | , , , , , , , , , , , , , |
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| Format: | Conference Object |
| Language: | English |
| Published: |
2017
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| Subjects: | |
| Online Access: | https://pure.au.dk/portal/da/publications/greening-the-high-arctic--when-and-how-have-seabirds-transformed-the-fresh-waters-of-the-now-polynya(35ff375c-cc6f-4caa-b42e-18dacb76c504).html http://conferences.au.dk/fileadmin/conferences/2017/NOW/NOW_Conference_web_14nov_Final.pdf |
| Summary: | The North Water Polynya (NOW) is host to an exceptionally large number of seabirds, which gather in large colonies over the brief summer months. These birds link marine and terrestrial ecosystems as they rely on the productivity of the marine polynya for their sustenance but use the terrestrial environment as breeding sites. Here, we examine how the little auk (Alle alle), alters freshwater and terrestrial ecosystems using stable isotope ratios (δ15N and δ13C) of freshwater and terrestrial biota, terrestrial vegetation indices and physical– chemical properties, productivity and community structure of fresh waters in catchments with and without little auk colonies. We then examine the long-term patterns of presence, absence and abundance of a range seabirds across the NOW using palaeoecological approaches. Lake sediment core were taken from lakes within little auk colonies on Salva Ø and at Annikitsoq on the Cape York peninsula. Peat cores were extracted at sites with little auk colonies at Søkongdale, Annikitsoq, and Robertson fjord, from Eider duck colonies at Three Sister Bees and Booth Sound and from a thick billed Murre colony on Saunders Island. δ15N values provided an unequivocal signature of bird arrival at the lake sites, whereas radiometric dating of the basal sample of a peat deposit provides a minimum maximum age. 14C dating of the peat cores suggest that eider and thick billed mure have a long history of presence in the NOW going back over 5000 years. Whereas the little auk colonies appear the have arrived at the coring sites 4300 years before present, whereas the peat cores are dated to circa 2400 years BP. We discuss how the arrival and abundance of bird colonies may relate to Holocene climate variation and the history of human habitation. |
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