Abstract
Successful refloating of live-stranded whales is logistically challenging due to their large size and is complicated by the urgency posed by their rapid physiological decline when grounded or out of water. A sub-adult, male gray whale (Eschrichtius robustus) measuring 730 cm (24 feet) in length, estimated to weigh 3,700 kilograms, and in good body condition (BCS 3/5) stranded for unknown reasons on August 16, 2017, on the outer coast of Washington State and was refloated on August 19, 2017. The whale was alert and responsive to the presence of people throughout the stranding. Responses included head lifting, mouth opening, pectoral fin slapping, and tail fluke movement. Respiratory rate was constant throughout the three-day stranding period at 2 to 4 breaths per minute. Pronounced horizontal nystagmus was present. Basic supportive care measures were initiated immediately and maintained throughout the stranding. These included covering the body of the whale during daylight hours with wet cloths and a shade tent, and a large public barrier. Low-dose midazolam (0.03 mg/kg) was administered on day two and day three to provide anxiolysis and reduce the negative physiological impacts related to the stress of stranding including tachycardia and hyperthermia. Mixed vitamin B complex (10 mcg/kg) and dexamethasone SP (0.1 mg/kg) were administered intramuscularly for their individual therapeutic values and potential antinociceptive synergy during the low-tide prior to the refloat attempt on day three.1 All injections were administered in the dorsal epaxial musculature at the level of the pectoral fins via 91 cm (36 inch) 18 gauge needles. Certain medical procedures, including phlebotomy and oral gavage for hydration, were not feasible due to the active state of the animal. A harness was rigged on the whale at low tide by passing a 2.5 cm (1 inch) double braided nylon rope under both pectoral fins and over the back of the animal leading forward to a 20 cm (8 inch) single block pulley system anchored approximately 45 m (150 feet) offshore in ~ 3 m of water depth with a 36 kg (80 pound) Danforth-type anchor. The harness pulley system was designed to aid in turning the whale seaward and preventing the whale from being pushed further onshore as the high tide returned. The harness was connected to the pulley line using a remote detachment system to ensure none of the harness and rope from the pulley system remained on the animal upon release. During high tide, the animal was successfully refloated with 25 responders working on the pulley system. Active surveillance of the region’s beaches including systematic beach surveys for 2 weeks and one aerial survey did not detect re-stranding. Images for individual identification and skin samples for genetics were collected from the whale for potential future matching. Coordinated and collaborative responses, such as demonstrated in this case, improve medical and technical capacity for effectively responding to large stranded marine wildlife, including endangered and threatened marine mammals such as Southern Resident Killer Whales (Orcinus orca) and humpback whales (Megaptera novaeangliae).2
Acknowledgements
The authors thank the numerous volunteers who made this response effort possible. In addition, we thank Dr. Michael Moore of Woods Hole Oceanographic Institute, Dr. Cara Field of The Marine Mammal Center, and the National Park Service and staff from Olympic National Park for their support and technical assistance.
* Presenting author
Literature Cited
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2. Geraci JR, Lounsbury VJ. 2005. Marine Mammals Ashore: A Field Guide for Strandings. 2nd ed. National Aquarium in Baltimore, Baltimore, MD. 371.