Oregon Spotted Frogs are extremely rare in British Columbia, and they have likely been extirpated from much of their historical range. Oregon Spotted Frogs are much more aquatic than other species and rarely move between ponds, except through waterways, making them highly susceptible to habitat fragmentation. A large swatch of Oregon Spotted Frog habitat was lost when the Sumas Lake area was diked and drained in the early 1900s. Exotic species may also influence Oregon Spotted Frog viability such as American Bullfrogs and Reed Canary Grass (Phalaris arundinacea), which overgrows shallow, warm waters that Oregon Spotted Frogs prefer for breeding and foraging. Reed Canary Grass is found at every site in British Columbia known to contain Oregon Spotted Frogs. The communal egg-laying habit of Oregon Spotted Frogs has also contributed to their decline. Several females (up to 100 in some cases) will lay their eggs in the same spot, often on top of each other. If water depth, temperature, or chemistry change drastically in that area, some (or all) of the egg masses can be lost. Road mortality does not appear to be an issue for this species, as they rarely move into terrestrial habitats. Pollution from pesticides and herbicides, road salt, and sediment from forestry can cause mortality and developmental defects. They may also be susceptible to pathogens such as Chytrid fungus and Ranavirus. Climate change is a threat to all frog species as it may increase the frequency and severity of drought and flood events.