Climate change has a wide range of effects with the potential to cause broad changes in marine ecosystems. The Arctic is predicted to be one of the most highly impacted areas, with average temperatures increasing by as much as 3-5°C. As temperatures rise, Arctic sea ice is disappearing earlier each year, leading to changes in the ocean environment. Thick-billed murres (Uria lomvia) (TBMU) and northern fulmars (Fulmarus glacialis) were collected at colonies in the eastern Canadian Arctic to examine potential changes in Arctic marine food webs over the past three decades.
Otoliths and invertebrates were examined in the murre stomachs, and the results compared to data collected from the same colonies in the 1970s and 1980s. Few changes were observed in the diets of the high Arctic thick-billed murres where the ice-associated Arctic cod continue to dominant the prey items found in the thick-billed murres. Significant changes were found in birds sampled from the low and mid-Arctic. In the low Arctic, Arctic cod has declined across all of the colonies sampled, while the capelin, which is a sub-Arctic species, has become dominant in the diets of the birds in the low Arctic and a common prey species mid-Arctic where it was not observed in the diet of TBMUs previously, indicating a northward expansion of this species. The proportion of invertebrate species has changed in some zones and mysids now constitute a large proportion of the murre diet in the low and mid Arctic where hyperid and gammarid amphipods used to be the main invertebrate consumed.
The birds can be used as samplers of the marine environment, and as integrators of the environmental changes that are occurring, but prey were not the only items found in the stomachs on birds sampled. Marine plastic debris was also found in the stomach contents of both murres and fulmars from every colony sampled indicating plastic ingestion is becoming a widespread problem for Arctic seabirds. Plastics found in northern fulmars indicate that marine plastic debris is increasing in the Arctic Archipelago, and monitoring of this recognized indicator species of plastic debris will allow long term monitoring of man-made debris in Canada’s north. Plastic debris was also found in thick-billed murres from all of the colonies sampled. Although murres are not useful indicators of general marine plastic debris the presence of plastics at all the colonies sampled indicate that plastics are not just a problem for surface feeding seabirds, but a threat to a number of species found in Canadian waters.
| Identifer | oai:union.ndltd.org:uvic.ca/oai:dspace.library.uvic.ca:1828/3003 |
| Date | 31 August 2010 |
| Creators | Provencher, Jennifer |
| Contributors | Dower, John F., O'Hara, Patrick D. |
| Source Sets | University of Victoria |
| Language | English, English |
| Detected Language | English |
| Type | Thesis |
| Rights | Available to the World Wide Web |
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