Jacqueline Schoen: Short-Term Impacts of the Site C Dam on a Declining Aerial Insectivore: The Bank Swallow

Hydroelectricity is one of the largest sources of renewable energy globally, and currently generates the majority of Canadian power. However, dams reduce water velocity slowing down erosion processes, reduce the availability of low-lying wetlands for foraging, and likely lead to accumulation of heavy metals in the environment. The Peace River is the site for BC Hydro’s third hydroelectric project, Site C dam. The Peace is also home to one of the largest populations of Bank Swallows in the province, with an estimated 60+ breeding colonies and over 1,700 nests. Bank Swallows are Threatened in Canada under the federal Species at Risk Act; since the 1970s, Bank Swallow populations have declined in Canada by over 90%. During the 2021 and 2023 breeding seasons, 212 feather and 195 blood samples were collected from 22 colonies, both upstream and downstream of the site C dam construction. Using these samples, we have compared how Bank Swallow diet quality has changed both over time and spatially in relation to the dam construction, and whether heavy metals are being bioaccumulated in the population. Overall, we are exploring how the cumulative effects of this dam may alter the environment and consequently affect the health, survival, and fitness of this threatened species.