survive winters in larger numbers and expand their range. Hunting, gathering and certain forms of food preparation and preservation methods may increase the risk of zoonotic infections (Hueffer et al., 2013). The frequency of contagious diseases in Arctic species has increased, for example, avian cholera outbreaks inmarine birds in the northern Bering Sea and Arctic Archipelago, and mortalities in seals and walruses in the US Arctic (CAFF, 2017). Thawing permafrost on land also has the potential to release previously immobile spores of anthrax, as shown by the outbreak inYamal in the Russian Arctic in 2016, whichwas widely covered in themedia and resulted in the death of a 12-year-old boy, the hospitalization of around 100 people and the death of 2,300 reindeer (Goudarzi, 2016). However, even if the risk of anthrax outbreaks is linked to a warming climate and the Arctic has the right conditions for them, outbreaks have been muchmore common further south and this situation is predicted to continue (Walsh et al., 2018).
Insects like mosquitoes and ticks have the potential to connect the Arctic and tropics (Evengård and Sauerborn, 2009) and there is already evidence of the northward spread of zoonotic diseases across Canada, Russia and Europe. For example, the number of reported cases of Lyme disease in Canada, which is transmitted by the black-legged tick, has been steadily rising in the last 10 years and has doubled between 2016 and 2017 (Government of Canada, 2018). Climate warming is expected to support further expansion northwards, with the increase in the number of days over 0°C being the most important determinant for the establishment of ticks (Leighton et al., 2012). Migratory birds also have the potential to transmit ticks over long distances. Further research is needed to better understand the distribution and spread of climate-sensitive infectious diseases in Arctic ecosystems and societies to develop early warning systems and preventive measures.