Iceland’s remoteness has greatly limited the number of native animal species. Only one land mammal, the Arctic fox (Vulpes lagopus), has colonised Iceland on its own. Other species have been introduced by humans, some intentionally but others by accident. Some species have adapted to conditions in Iceland well and are generally recognised as part of the Icelandic fauna, including the wood mouse (Apodemus sylvaticus) and reindeer (Rangifer tarandus). Not all introduced species are well liked. The mink (Mustela vison) is classified as an invasive species in Iceland. Mink were initially brought to Iceland for fur farming, but soon escaped into the wild. A feral population was quick to adapt to Iceland’s natural environment and now has a wide distribution in Iceland. The introduction of this species has been detrimental to birdlife in Iceland and caused changes to birds’ breeding behaviour.
Insects and animal pests have been introduced to Iceland by humans from the earliest settlement times. Many species today classified as native to Iceland certainly arrived due to human activity. Introduction of small animals and insects has become significantly more common in recent years, due to burgeoning importation of goods and merchandise from around the world. To date, few of these accidental imports have gained a foothold. Climate change will, however, improve the prospects of some species, opening a window for colonisation of Iceland. This has become increasingly apparent in recent years, as numerous species have established a presence here in Iceland. Most of these species inhabit man-made habitats, such as inhabited areas, gardens, and disturbed habitats. They will continue to bide their time in such areas until conditions change to the point where they are able to spread to the natural environment. Some of these species are pests in the human environment.
Three species introduced by humans have been defined as invasive in Iceland. An invasive species is an introduced species that negatively impacts other species accepted as native to a given environment. The Spanish slug (Arion vulgaris) has been brought to Iceland with imported plants. In Northern European countries it is defined as an invasive species. In Iceland it is still too rare to deserve that definition, but the potential should not be ignored.
The fresh water snail (Physella heterostropha) has been imported as an aquarium species. The snail has been introduced to lakes where aquariums have been emptied. In these lakes, the snail is a potential competitor for native water snails.
The white-tailed bumble-bee (Bombus lucorum) was inadvertently introduced to Iceland in the 1970s due to importation of goods. The species rapidly colonised both populated areas and natural habitats. At the same time, the heath bumble-bee (Bombus jonellus) population began to fall. Until recently, the heath bumble-bee was the only bumble-bee species in Iceland. The white-tailed bumble-bee is larger and more aggressive in visiting the flowers that are their food source. Other bumble-bee species have established populations in Iceland in recent years, but they have not colonised natural habitats and are unlikely to do so.
Introduction of new species with imported goods cannot be fully prevented. However, more strict regulation of gardening products is necessary, particularly concerning the importation of soil and potted plants. Garden soil should be specially handled before it is distributed. Many colonisers have been introduced to Iceland in recent decades. Some have proved invasive and detrimental, but their effects have been limited mainly to gardens and the human environment. A warming climate is likely to increase the impact of invasive species on nature in Iceland.
The Icelandic Institute of Natural History participates in the North European and Baltic Network on Invasive Alien Species (NOBANIS) on behalf of Iceland. This collaborative project between North and Central European states aims to minimise or prevent the damage caused by invasive species. In compiling information for this project, numerous experts at the IINH and elsewhere have provided their assistance. The main goal of NOBANIS is to act as a regional portal for sharing information on exotic and invasive species in North and Central Europe and to make this data available online. The resources accessible through the portal include information on the number of invasive or potentially invasive species in Iceland.