Evolution, Ecology, and Conservation of Dolly Varden, White spotted Char, and Bull Trout

Abstract

AbstractWe review the ecology and conservation of three lesser‐known chars (genus Salvelinus): Dolly Varden (S. malma), white‐spotted char (S. leucomaenis), and bull trout (S. confluentus). Dolly Varden is distributed across the northern Pacific Rim and co‐occurs with bull trout and white‐spotted char at the southern extremes of its range. In contrast, bull trout and white‐spotted char are naturally isolated, with the former restricted to North America and the latter distributed in northeastern Asia. Though the range of Dolly Varden overlaps with the two other chars, it is most closely related to Arctic char (S. alpinus), whereas bull trout and white‐spotted char are sister taxa. Each species exhibits diverse life histories with respect to demographic characteristics, trophic ecology, and movement. This diversity appears to be tied to environmental variability (e.g., temperature, habitat connectivity), resource availability (e.g., food), and species interactions. Increasingly, these interactions involve nonnative species including nonnative salmonines and changes in food webs related to establishment of species such as Mysis shrimp in large lakes. As humans expand into the remote and pristine habitats that support these three chars, we encourage proactive consideration of the lessons learned where chars have already declined and internationally‐based research and conservation.