Mammals

Beavers are typically associated with freshwater environments, but scientists have learned that they also survive and thrive in the shoreline marshes of the Salish Sea. New research is revealing the vital connection between tidal beavers and salmon.

Pink salmon now comprise nearly 80 percent of all adult salmon in the North Pacific. This record abundance is coming at a cost to other salmon species such as threatened Chinook, which compete with pinks for spawning territory. A new study shows that the ecological toll may extend all the way to endangered southern resident killer whales.

While not true marine mammals, river otters do use and rely on marine resources. The expansion of their populations since the early 1900s is a true conservation success story. Ecosystem recovery efforts and river otter reintroductions restored otter populations to much of their historic range. River otters often live in small social groups that include mother and offspring or other unrelated adults.

Just last year, scientists published the first direct evidence that noise interferes with orca feeding behavior. Officials hope a new law establishing a larger buffer zone between boats and endangered southern resident orcas will mean quieter seas and healthier whales.

The appropriately named common dolphin is probably the most abundant cetacean on the planet. Common dolphins occur in most of the world’s tropical and temperate waters. Historically, they have not been common in inshore waters in Puget Sound and the Salish Sea but they are becoming more frequent as water temperatures warm.

Pacific white-sided dolphins (Lagenorhynchus obliquidens) are found in the colder offshore waters of the North Pacific, but they also occasionally occur in inshore waters of the Salish Sea, and more rarely, Puget Sound. They make use of cooperative foraging techniques, and feeding at night in dark conditions means their finely tuned sonar or echolocation serves them well.