Parasite Communities in Artic Blue Mussels - Exploring Spatial and Temporal Dynamics

Abstract

Blue mussels (Mytilus spp.) play an important role in intertidal ecosystems along coastlines worldwide. Trematodes, which often parasitize these mollusks, can effectively alter blue mussels’ functional role in intertidal ecosystems. Due to the trematodes complicated life cycles and manifold but hidden effects on the intertidal ecosystems, they are often ignored in marine research, especially in understudied areas. This study explores the community dynamics of trematodes within Artic Norwegian blue mussels on various spatial and temporal scales. In the Sommarøy area, differences in trematode infection intensity and infection prevalence between human-influenced and natural sampling locations, between wave-exposed and sheltered sampling sites, and differences along the intertidal gradient and seasonal dynamics were tested. In a sample of 1557 blue mussels, three trematode species were identified (Renicola sp., Gymnophallus sp., and Himasthla sp.), of which Renicola sp. and Gymnophallus sp. occurred frequently. The abundance of Renicola sp. was negatively affected by human influence, wave exposure, and an increase in intertidal level, while no such trends were observed for Gymnophallus sp. Further, it was observed that Renicola sp. increased slightly in infection intensity in the later phase of the vegetative period (fall) in Arctic intertidal zones. This thesis takes a multidimensional approach to unravel antagonistic, interactive, and additive effects on the infection dynamics of trematodes within blue mussels and provides a baseline to understand these organisms and their implications in Arctic ecosystems.