The largest of all dolphins (the Delphidae family), the orca is also known as killer whale, blackfish and grampus. At birth an orca can weigh up to 395 lbs. The adult weight can range from 2.6 tons to 9 tons. Orcas can swim up to 34 mph (55 km/h). A female orca’s milk contains about 48% fat for several months after her calf is born.  During first several months of its life, the calf will often consume 10% of its body weight per day in order to develop a thick layer of insulating fat, or “blubber”, on its body.…

Orca aren’t the only whales found in the waters of the San Juan Islands. Northern minke whales also live in the inland coastal waters of Washington but can be shy of boat traffic.

The primary food source for the Southern Resident orcas is salmon. In fact, approximately 80-90% of a Resident orca’s diet is composed of these fish. A National Marine Fisheries Service study in March 2010 found that orca whales consume a specific species, the Chinook salmon. Also known as King or Tyee salmon, the Chinook salmon (Oncorhynchus tshawystscha) stocks originate in rivers from central California to northwest Alaska. These salmon are anadromous, which means that they spend the majority of their life in the ocean but return to their natal freshwater streams to spawn, or reproduce. Chinook are typically the largest…