North American river otters (Lontra canadensis) are semi-aquatic mammals that range over most major river drainages, large lakes, and coastal marshes of North America. On the west coast, from Northern California (Bouley et al., 2015) to Alaska (Bowyer et al., 2003), river otters forage in and rely on healthy subtidal and intertidal zones where they feed on a variety of marine fish and invertebrates. The subspecies L. c. pacifica is found throughout the Salish Sea’s rivers, estuaries, coastlines, and coastal islands and plays an important role in the nearshore marine ecosystem. They are often confused with sea otters (Enhydra lutra) by the public because they are otters swimming in the sea. River otters do use and rely on marine resources, but taxonomically, they are not considered marine mammals like sea otters.