Are they dangerous?
There is only one dangerous invertebrate on Svalbard, the worm Echinococcus mulitilocularis found associated with the foxes and voles around the deserted Russian mine at Grumont. Infection with this parasite can lead to a serious and fatal disease. However, this parasite is found over wide areas of Europe and North America and while personal hygiene when visiting Grumont must be observed, there is only a very small likelihood of becoming infected.
Of a bigger nuisance are the mosquitoes. There is one species of mosquito on Svalbard, Aedes nigripes. This species has a broad distribution around the Arctic including Greenland and northern Canada. On Svalbard it is found in particularly high densities at Kapp Thordsen, Brucebyen and even up Adventdalen. While it is rare in Ny-Ålesund it can become a problem on Blomstrandhalvøya. It is not thought that the mosquito on Svalbard spreads human diseases.
While there are few invertebrates that are dangerous to humans there are many that exploit other mammals as hosts, for example the nematode gut parasites of the reindeer. These may have effects on the pregnancy rates of the reindeer and hence effect host population dynamics but the effects are difficult to unravel from other environmental stress factors such as hard winters with significant surface icing.
Bird tick densities seem to be increasing in Svalbard (click here). Feeding by these ticks may result in the host loosing blood and/or irritation, both of which may have negative effects on breeding success. But a recent invetigation of bird ticks in Svalbard failed to detect the presence of tick-bourne viruses (Elsterová et al. in press).