The impact of climate change on the American mink in Iceland
The impact of climate change on the diet of American mink in the Snaefellsnes Peninsula, Iceland
The American mink has been present in Iceland since the 1930’s and despite heavy hunting since 1939 the species has become well established. The ecosystem in Iceland is simpler than in other areas where mink are found; the only other mammalian predator is the arctic fox. Direct competition between these species appears to be minimal although the arctic fox will sometimes chase mink and disturb them while foraging. Iceland is therefore an ideal place to study undisturbed feeding behaviour and ecology of mink.
Various marine changes have occurred in Iceland in past years. The Iceland scallop population in Breidafjordur has decreased since 2000 and suffered increasingly poor conditions. The sandeel population has been decreasing for more than a decade and suffered from a severe recruitment failure in 2005 and 2006. This had a major impact on recruitment in seabird populations, notably arctic tern populations, and the puffin population in the Westman Islands. A study conducted in the Snaefellsnes Peninsula, West Iceland, revealed a 46% decrease in the mink population size there between the years 2002 and 2006. Since these coastal mink feed mainly on fish, the decrease in population size might be linked to the recent marine species collapse, which has been associated with climate change.
During this 3-year project, we will analyse the contents of alimentary tracts obtained from mink in and around the Snæfellsnes Peninsula in the years 2002-2008. Stable isotope analysis on bones and soft tissues of yearling mink will be conducted, which allows assessment of the diet (terrestrical versus marine) of each animal at three levels:
1. Stomach content: What the mink ate the day it was killed
2. Soft tissues: Diet in the last few months
3. Bones: Diet in the first year of life
Building on the information obtained from these analyses, we aim to construct a dietary model, explaining the influence of various abiotic factors, and thus to assess the potential impact of climate change.