Biology

Michael J. Gill, Topic Editor

Chair, Circumpolar Biodiversity Monitoring Program, Environment Canada, Whitehorse, Yukon CA

October 15, 2010

Summary

The contribution of Arctic wildlife to global biodiversity is substantial. The region supports globally significant populations of birds, mammals and fish. For example, over half of the world's shorebirds and 80% of the global goose population breed in Arctic and sub-Arctic regions. Many of these populations experience natural and often dramatic cycles in abundance, switching from periods of growth and decline. Dramatic changes (e.g., sea-ice loss) in the Arctic's ecosystems have occurred, are predicted to continue over the next century, and may disrupt these natural cycles. Changes in physical attributes of the Arctic (e.g. increasing air temperatures, decreasing sea ice extent) are expected to result in winners and losers. Arctic species that have adapted to these extreme environments are expected to be displaced by the encroachment of more southerly (sub-Arctic) species and ecosystems. Understanding how the Arctic's living resources are responding to these changes is essential in order to develop effective conservation and adaptation strategies.

The biological components of the 2010 Arctic Report Cards highlight the inherently fluctuating nature of Arctic ecosystems and provide some insight into how Arctic ecosystems and the biodiversity they support are responding to changing environmental conditions. Dramatic declines in many wild caribou and reindeer populations over the past two decades and the dramatic increases in goose populations over the same period appear to be moderating. Barents Sea harvested stocks continue to fluctuate and these changes may be linked to sea temperatures and the associated fluctuations in sea ice cover. The Arctic Species Trend Index, released in 2010 and drawing on 965 populations of 306 Arctic and sub-Arctic vertebrate species across the Arctic, has been relatively stable since 1970. However, there are significant variations between groups and species, and geographic areas. Populations of vertebrate high arctic species declined 26% between 1970 and 2004. Low and sub-Arctic species have fared better over this time period: the low Arctic species index, largely dominated by marine species, has experienced increasing abundance (although the result is largely biased by pelagic data from the Bering Sea), while the sub-Arctic index (reflecting mostly terrestrial and freshwater species) has declined since the mid-1980s, resulting in no overall change over the 34 year period. These observed trends are largely consistent with current predictions regarding the response of Arctic wildlife to changing environmental conditions in the Arctic, caused by both natural and human-caused change. Given the predicted dramatic changes in the Arctic over the next century (e.g. from climate change), it is becoming increasingly important to invest in improved monitoring in this remote area to understand how these systems are changing and thereby facilitate more effective and timely conservation and adaptation actions.

Biology Essays:

• State of Reindeer herds
• Marine Mammals
• Murres
• Fisheries in the Bering Sea
• Fisheries in the Barents Sea
• Arctic Char
• Goose Populations
• Arctic Wildlife

Additional Information:

2010 State of the Environment: Biodiversity Special Report from the Canadian Northwest Territories

About the Report Card

Printable Handout :: Executive Summary :: Full Arctic Report Card (PDF)
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