Abstract

National Oceanic and Atmospheric Administration (NOAA) Fisheries in cooperation with Fisheries and Oceans-Canada, the Vancouver Aquarium and numerous advocacy groups in Washington State and British Columbia rescued, rehabilitated and released a lone, orphaned female juvenile orca in the Pacific Northwest. The two-year-old whale, identified as A73 of the northern resident population, was separated from her natal pod and found living in Puget Sound, several hundred kilometers from her home range. Scientists observed her over several months during the spring of 2002 and reported that she appeared underweight, had a ketotic odor to her breath, and was suffering from a dermatological disease of unknown origin. They also reported that she was exhibiting increased interactions with vessels. Based on concerns for the health and safety for her and for boaters using Puget Sound, NOAA Fisheries assembled a team of experienced researchers, husbandry personnel and veterinarians to rescue the 600-kilogram animal in mid June and transported her a short distance to a floating net pen at a NOAA facility, near Seattle, for rehabilitation.

The medical team initiated a health assessment on the free-swimming whale in situ prior to capture and conducted intense diagnostic tests and behavioral observations throughout her rehabilitation. She was treated for a mild contracecum infestation and for an elevated erysipelothrix antibody titer. Efforts were made to limit her interactions with rehabilitation personnel who observed the animal's progress via remote video monitoring. Blind feeding techniques and environmental enrichment were also part of the rehabilitation regime. After one month of treatment in the rehabilitation pen, the whale was transported to Hanson Island, British Columbia for reintroduction to the wild in the heart of the whale's summer range. Following transport, A73 was allowed to stabilize briefly in a floating pen prior to being fitted with several suction cup telemetry tags. She was released in close proximity to a related pod of whales. Post release monitoring was conducted from vessels, using telemetry and visual observations, over the next several weeks. The young whale migrated from the summer range with her pod mates in the fall and observers await her anticipated return in the spring. This is the first time that an orphaned orca has been successfully rehabilitated and released in North America.