Although the majority of Arctic species are not currently declining, some harvested species of importance to Arctic people or species of global significance are declining.

Wild reindeer and caribou are very important to the livelihoods of Arctic peoples. Since the 1990s and early 2000s, however, herds have declined by about one-third, from 5.6 to 3.8 million. While this may be a result of naturally occurring cycles, the ability of these populations to rebound is uncertain given the multiple stressors to which they are now exposed, such as climate change and increased human activity.

Although much has been learned, information is deficient on many species and the relationship to their habitat. Even for charismatic animals such as the polar bear, trends are known for only 12 of 19 subpopulations; eight of these are declining.

Arctic shorebirds, such as the red knot, migrate long distances to breed in the Arctic. Evidence indicates that shorebird populations are declining globally. Of the six subspecies of red knot, three are declining while the other three are either suspected of being in decline or their status is unknown.

The Arctic Species Trend Index (ASTI), which provides a snapshot of vertebrate population trends over the past 34 years, shows a moderate 10% overall decline in terrestrial vertebrate populations. The decline partially reflects declining numbers of some herbivores, such as caribou and lemmings, in the high Arctic. In the low Arctic, vertebrate populations have increased, driven by dramatically increasing populations of some goose species, which have now exceeded the carrying capacity of the environment to support them.

Populations of some very abundant seabirds, such as common eiders, are generally healthy. Some Arctic seabird populations, such as murres, may be showing divergent trends. Their populations fluctuate in relation to major climate regimes in the Northern hemisphere, while others are still affected by overharvesting.

Freshwater Arctic char populations appear to be healthy in comparison to those in more southern locations. For marine fish, there is evidence of a northward shift in the distribution of some species in both exploited and unexploited stocks. The shifts appear to be the result of climate change, in addition to other pressures, such as fishing.