Abstract
A harbour porpoise calf, Phocoena phocoena, weighing 12.65 kg, was found stranded on Gonzales Beach, Victoria, British Columbia, Canada, on August 26, 2008. She was brought to The Vancouver Aquarium's Marine Mammal Rescue Centre (VAMMRC) via the Department of Fisheries and Oceans Canada (DFO). Based on her size, lack of fetal folds and teeth that had just started to erupt, Daisy (named by DFO officers) was estimated to be approximately six to eight weeks of age when she stranded and considered to be a dependent calf. Based on her age, poor body condition, blood results, and the fact that she improved in response to supportive therapy, it is likely that she stranded due to being extremely weak and malnourished as a result of maternal separation.
Once stabilized, antibiotics were administered to prevent secondary infection. Heart rate was monitored every hour while respiration was monitored every 10 minutes for the first 6 days and as per required after that. Supportive fluid therapy and nutrition were provided on a 24 hours a day basis. Initial rehydration included swimming in fresh water for the first 24 hours and administration of an electrolyte solution via gavage. Energy requirements were initially estimated at 200 kcal/kg/24/hr, however a mean of 311 kcal/kg/24hr over the next 71days, resulting in a weight gain of 203%. The diet included a fish based formula (310kcal/100ml) mixed with an electrolyte solution (40% of the volume of the formula at 7kcal/100ml) added to dilute the formula and administered by gastric gavage every 2 hours for the first 30 days, then a mean of 2.7 hours for the next 41 days.
On admission, the porpoise was extremely weak, could not support herself in the water and could not move her peduncle and appendages sufficiently to swim or stay afloat. She spent most of her time in a specially designed floatation sling or physically supported by staff or volunteers. With ongoing physiotherapy and support, the porpoise gained strength and slowly increased her range of motion. She was able to swim freely, 24 hours a day, on her own at day 44. She was deemed non-releasable by DFO and transferred to The Vancouver Aquarium on July 28, 2009, where she remains today. This case highlights the special metabolic requirements of a harbour porpoise calf. This successful effort was likely due to a rapid response and rescue, close monitoring of nutritional status, and intensive supportive therapy by a dedicated group of staff and volunteers.
Acknowledgements
The authors would like to extend tremendous gratitude to The Department of Fisheries and Oceans Canada for their support and the Vancouver Aquarium's Marine Mammal Rescue staff and volunteers for all their hard work and dedication. Additional thanks goes to the Marine Mammal and Animal Care Departments at the Vancouver Aquarium.