DAO prepress abstract  -  DOI: https://doi.org/10.3354/dao03182

Quantifying parasite presence in relation to biological parameters of harbour porpoises Phocoena phocoena stranded on the Dutch coast

Mariëlle T. I. ten Doeschate*, Lonneke L. IJsseldijk, Sjoukje Hiemstra, Els A. de Jong, Arjen Strijkstra, Andrea Gröne, Lineke Begeman

*Email: marieltdoeschate@gmail.com

ABSTRACT: Harbour porpoises are often found to be infected by endoparasites in several organs including the lungs and stomachs as well as the heart, liver and ear. Nevertheless there is still little knowledge about the impact, ecology, transmission, and virulence of these parasitic infections. Here, we profile the presence of parasites in four frequently infected organs (lungs, stomach, liver and ears) in relation to biological parameters of harbour porpoises stranded along the Dutch coastline between December 2008-2013. We found that parasites are a common finding, with prevalence being 68% in lungs, 74.4% in ears, 26% in stomach and 23.5% in liver. We used Generalised Linear Models to further quantify parasite presence in relation to biological data gathered during necropsy (sex, body length and nutritive condition). Body length (used as a proxy for age) was significant in explaining parasite presence for all organs with increasing probability of having the parasite with increasing body length. For the parasitic infections in the ears and stomach the nutritive condition was additionally a significant factor, with a higher probability of parasite presence in porpoises in a poorer nutritive condition. The results of this study can be used as a baseline for assessing parasite presence in harbour porpoises and was the first step towards linking parasite infections to basic biological data gathered during necropsy.