Tracking Trends in Arctic Wildlife: The Arctic Species Trend Index

For the first time, an index providing a pan-Arctic perspective on trends in the Arctic's living resources has been developed. The Arctic Species Trend Index (ASTI), like the global Living Planet Index (LPI), illustrates overall vertebrate population trends by integrating vertebrate population trend data of an appropriate standard from across the Arctic and over the last 34 years (1970 as the baseline). An increasing index indicates that overall more vertebrate populations in the Arctic are increasing than decreasing. Whereas a decreasing index, indicates the opposite situation. The ASTI not only allows for a composite measure of the overall trajectory of Arctic vertebrate populations, but can be disaggregated to investigate and display trends based on taxonomy, biome, region, time period and other categories. These disaggregations reveal underlying trends in abundance and can help identify groups of species and regions for which change has been most rapid. Over time, tracking this index will help reveal patterns in arctic wildlife response to growing pressures, thereby facilitating a better predictive ability on the trajectory of arctic ecosystems.

A total of 965 populations of 306 species (representing 35% of all known arctic vertebrate species) were used to generate the ASTI. In contrast to the global LPI, whose overall decline is largely driven by declines in tropical vertebrate populations, the average population of arctic species rose by 16% between 1970 and 2004. This pattern is very similar to the temperate LPI and is consistent in both the North American and Eurasian Arctic. The overall increasing trend in the Arctic is thought to be partly driven by the recovery of some vertebrate populations (e.g. marine mammals) from historical overharvesting as well as from recent changes in environmental conditions both inside (e.g. Bering Sea Pollock) and outside of the Arctic (e.g. Lesser Snow Geese) resulting in dramatic increases in some species' populations. This increasing trend however, is not consistent across biomes, regions or groups of species.

This presentation will present results of various analyses of trends in arctic vertebrates and will highlight the need to expand the current extent of arctic monitoring by targeted data collection to fill gaps in the data set and by engaging the network of arctic nations to increase monitoring efforts.