Location: Animal Parasitic Diseases
Title: Invasion, establishment, and range expansion of two parasitic nematodes in the Canadian Arctic Authors
Submitted to: Global Change Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 25, 2013
Publication Date: November 1, 2013
Citation: Kutz, S.J., Checkley, S., Verocai, G.G., Dumond, M., Hoberg, E.P., Wu, J., Orsel, K., Seegers, K., Warren, A., Abrams, A. 2013. Invasion, establishment, and range expansion of two parasitic nematodes in the Canadian Arctic. Global Change Biology. 19(11):3254-3262. Interpretive Summary: Climate warming is being implicated as a critical driver of environmental change with substantial implications for new patterns of parasite and pathogen distribution on varying geographic and temporal scales. Examples of new host and geographic ranges for pathogens have become apparent over the past decade as accelerated climate warming influences the structure and function of complex ecosystems. The Arctic in this regard is an important model-system for changing climate, and global warming is modifying host-parasite interactions across this region. Collaborative and field-based research linking laboratories and complementary expertise at the University of Calgary, the Government of Nunavut, Canada and the US National Parasite Collection demonstrated recent invasion or geographic expansion from the mainland of Canada to an Arctic island by protostrongylid nematodes (lung-dwelling round worms), that are serious pathogens in either muskoxen or caribou. Historically these parasites had been confined to mainland habitats, a point indicated by extensive field surveys and comparisons to archival biological collections accumulated over past decades. The recent occurrence of the parasites was demonstrated initially by molecular based diagnostics which identified the occurrence of Umingmakstrongylus pallikuukensis in muskoxen and a species of Varestrongylus in muskoxen and caribou. Geographic expansion to island habitats appears mediated by sporadic dispersal of muskoxen and seasonal migration by caribou from the Canadian mainland. A newly permissive environment resulting from substantial warming in the past 20-30 years likely facilitated initial establishment and now drives continued range expansion for both parasites. Results of our research show the importance of archival biological collections as foundations for understanding the distribution of diversity for hosts and pathogens. Further these studies indicate the importance of integrating morphological and molecular methods for parasite identification such as those used in the current study. Recognition of a new and expanding geographic range for these parasites is important in the science of climate change, as this is one of few empirically demonstrated examples for invasion and emergence by helminth parasites, and one that serves to corroborate current theoretical and conceptual models. The results of the study are of significance for disease ecologists, wildlife biologists, veterinarians and others who are tracking the interactions of climate and environmental perturbation on patterns of distribution for disease organisms in both domestic and free-ranging ungulates and other animals.
Technical Abstract: Climate warming is modifying host-parasite interactions in the Arctic. Invasion of an arctic island by protostrongylid nematodes appears mediated by sporadic dispersal of muskoxen and seasonal migration by caribou from the Canadian mainland. A newly permissive environment likely facilitated initial establishment and now drives range expansion for both parasites.