Remote islands with high numbers of endemic species give us the opportunity to study unique aspects of intraspecific evolutionary history. Haida Gwaii, British Columbia, Canada, is such an intraspecific evolutionary history hotspot that served as a refuge during the last glaciation and resulted in species diversification. Today, Haida Gwaii is home to multiple endemic species as well as many unique forms of widespread species. However, these endemic species are currently facing multiple stressors including invasive species. The first goal of my project is to map the spatial patterns of community interactions in some of Haida Gwaii’s freshwater ecosystems by detecting invaders, their abundance and spread, and their patterns of co-occurrence and co-abundance with native species. The second goal of my project is to determine how environmental heterogeneity shapes the diversity of traits in an evolutionary model system and ecological keystone species, the threespine stickleback. My research will reveal the different factors interacting to shape the diversity found in Haida Gwaii’s threespine stickleback and will facilitate the identification of potential refuges from invasive species.
Environmental gradients, such as oxygen, temperature, or ions, have larger effects on some species than on others, raising questions as to how some species are able to persist across gradients when other species are not. We addressed this topic by considering how a critical fitness trait (scales) is influenced by a large environmental gradient in a key component of those scales (calcium). We find that all three studied native fish species are able to maintain a relatively consistent concentration of calcium in their scales across a massive gradient in calcium availability. This result suggests the presence of adaptive mechanisms enabling native fishes in low calcium conditions to better uptake, mobilize, and deposit calcium.