Andrea Morden
Project
The northern range extension of the invasive Asian clam (Corbicula fluminea)The Asian clam is a highly invasive freshwater bivalve that has spread globally and is well established in North America and Europe. Due to its subtropical origin, the Asian clam was thought to be limited to warm temperate water bodies. In the past decade, numerous populations have been detected in cold temperate water bodies that experience seasonal ice cover. In order to persist at these sites, the clams need to survive and recover from prolonged cold and potentially hypoxic conditions. Recent research in our lab indicates that there is significant variation in cold tolerance among North American Asian clam populations. I have found similar variation between three Asian clam populations’ tolerance to hypoxia at low temperatures, reflecting winter conditions in some ice-covered water bodies. My work has shown that hypoxia tolerance data generated from one population of an invasive species can be misleading when predicting habitat invasion risk. I am also generating a spatially explicit habitat suitability model to predict which regions in Canada are at risk of an Asian clam invasion under current and future climate scenarios. Given the Asian clam’s recent establishment in cold temperate water bodies, previous assumptions that Canadian waterways are immune to C. fluminea establishment may be erroneous. In order to support my assessment that recently detected Asian clam populations have persisted at a site long enough to include it in a habitat suitability model, I have also deployed an experiment testing the rates and stages of C. fluminea shell degradation, for a variety of populations with different shell morphologies across a range of habitats. This may assist me in inferring establishment history for a newly detected Asian clam population based on the quality of spent shells found at a site.
