PEARL Paleoecological Environmental Assessment and Research Laboratory

PEARL

P

aleoecological

E

nvironmental

A

ssessment and

R

esearch

L

aboratory
Queen's University

Tern Island Project

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Arctic terns (Sterna paradisaea). Arctic terns have the longest yearly migration of any bird species, with some individuals covering ~80,000 km annually. Metals and other contaminants accumulated over their long journeys are ultimately deposited near their nesting sites, in some instances to toxic concentrations. Image courtesy of Mark Mallory.

A nesting Arctic tern (Sterna paradisaea). Most Arctic terns return to the same area, and often the same colony, from where they were hatched. Sediment cores from ponds that drain nesting areas provide a means to track long-term population dynamics because wastes from the colony (ie, guano, carcasses, eggshells) impart a unique geochemical signature to the pond sediments. Image courtesy of Mark Mallory.

A breeding pair of common eider ducks (Somateria mollissima). The male has distinctive black and white plumage with a green nape, whereas the female is brown. Eiders nest on coastal islands in colonies that range from less than 100 to upwards of 10,000 individuals. By feeding in the ocean, but nesting on land, eiders transport and focus marine-derived nutrients and contaminants to terrestrial ecosystems. Image courtesy of Mark Mallory.

Male common eider (Somateria mollissima) with its distinctive black and white plumage and green nape. The common eider is the largest duck in the northern hemisphere with adult males reaching up to 3 kg. Waste products released from eider colonies leave distinct biogeochemical signatures in soils and ponds sediments located near their nesting sites and can be used to infer population dynamics and identify long-term breeding habitats. Images courtesy of Mark Mallory.

Male common eider (Somateria mollissima) with its distinctive black and white plumage and green nape. The common eider is the largest duck in the northern hemisphere with adult males reaching up to 3 kg. Waste products released from eider colonies leave distinct biogeochemical signatures in soils and ponds sediments located near their nesting sites and can be used to infer population dynamics and identify long-term breeding habitats. Images courtesy of Mark Mallory.

Female common eider (Somateria mollissima). Eiders are capable of diving up to 20 m to obtain their prey, which consists primarily of mussels, clams, scallops, sea urchins, starfish and crabs. Their diet largely determines the degree to which they will accumulate different environmental contaminants such as metals, which ultimately are released to the terrestrial environment near their nesting sites, via excrement and other waste products. Image courtesy of Mark Mallory.

Arctic tern (Sterna paradisaea) eggs. The harvesting of tern eggs, or egging, for subsistence living still occurs in some regions of the Arctic and may have contributed to the decline of some local bird populations. Sediment cores from ponds located near tern colonies may be used to infer long-term population dynamics because waste products from the terns leave distinct biogeochemical signatures that reflect past population numbers as well as contaminant loads of the birds themselves. Image courtesy of John Smol. Common eider (Somateria mollissima) eggs, shown in a nest of the renowned eider down that is much sought after as one of the lightest and most effective insulators. Sediment cores from ponds located near eider colonies may be used to infer long-term population dynamics because waste products from the eiders leave distinct biogeochemical signatures that reflect past population numbers as well as contaminant loads of the birds themselves. Image courtesy of John Smol. Eider Pond, shown here, is located in the central portion of Tern Island and is surrounded by approximately 50-100 common eider hens. (source: John P. Smol, Queen’s University).

Tern Pond, shown here, is located in the eastern portion of Tern Island and is surrounded by approximately 300 pairs of nesting terns. The closeness of Tern and Eider ponds to one another (about 1 km) minimizes any variability related to differences in climate, geology and atmospheric precipitation between the two study sites. This provides a rare opportunity to compare and contrast the impacts of different seabird species on freshwater habitats. (source: John P. Smol, Queen’s University). Sediment cores, such as this one recovered from Eider Pond, can be used to track past seabird inputs over long-term timescales because seabird wastes leave distinct geochemical signatures that reflect contaminant loads and even differences in diet. (source: John P. Smol, Queen’s University). In flight photograph of an Arctic tern (Sterna paradisaea). (source: John P. Smol, Queen’s University)

Arctic terns (Sterna paradisaea) flying overhead during the sampling of Tern Pond. The use of helmets and protective head gear was necessary during sampling of the pond, because terns will aggressively defend their nests from any perceived predators. (source: John P. Smol, Queen’s University). Arctic terns (Sterna paradisaea) flying overhead during the sampling of Tern Pond. The use of helmets and protective head gear was necessary during sampling of the pond, because terns will aggressively defend their nests from any perceived predators. (source: John P. Smol, Queen’s University).  The remoteness and small size of Tern Island greatly minimizes the numbers of terrestrial predators such as the Arctic fox; however, the nesting seabirds must be wary of attacks from aerial predators such as this long-tailed jaeger (Stercorarius longicaudus). (source: John P. Smol, Queen’s University).

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