Aurora, the Vancouver Aquarium's 20-year-old beluga whale, successfully gave birth at the facility at 3:39 p.m. Sunday afternoon.
Her labour began around noon Sunday when the calf's tail flukes emerged from the mother and became visible to mammal care staff.
The calf was born nearly three hours later when she twisted free to snap the umbilical cord.
In Pictures: Baby Beluga Birth
Her first movement was to break the water's surface and take her first breath.
Moments after the birth, the calf began swimming closely beside her mother. She could be seen bumping into the sides of the tank several times while trying to orient to her surroundings.
Aquarium President Dr. John Nightingale says it is a remarkable occasion.
"It's wonderful to have a birth," he said.
"The miracle of birth is wonderful, and when it's something as big as obvious and as well loved as a beluga its pretty special."
Both mother and calf are said to be in good health.
The newborn will remain unnamed until the fall, when it is expected members of the public will be invited to submit suggestions.
Sunday's delivery was smooth, according to Aquarium Vice-President Clint Wright.
"Aurora went through the birthing process very, very well," Wright said.
"She was very calm throughout; she certainly didn't look to be in any severe pain or discomfort."
In preparation for Sunday's birth, Aurora's other calves, Qila and Tiqa, were temporarily removed from the tank to allow the maximum space for her birth and avoid "interference from the other animals."
The pair will return to join Aurora and the new calf once the aquarium staff is certain that mom and the calf are ready to widen their social circle.
Staff veterinarian Dr. Martin Haulena says they are very confident about Aurora's mothering.
"Aurora has proven herself to be an excellent mother and grandmother and she has a very experienced veterinary and marine mammal care team standing by and ready to assist if required," he said.
Volunteers have been monitoring the beluga around the clock for signs the whale was ready to deliver her third calf.
Up until now, one-year-old Tiqa has been the youngest calf at the pool since her birth last June.
Aurora's male calf Tuvaq was born in the summer of 2002, but died three years later.
Beluga whales normally gestate for approximately 14 to 16 months. On average, they give birth every three years. Newborn belugas normally weight between 116 to 154 pounds (53 to 73 kg), and can be up to 1.5 metres in length.
A whale of a time
The Vancouver Aquarium obtained its first whale, Kavna, in 1976, seven years after the animal was captured in the Hudson Bay off Churchill, Manitoba.
Imaq was taken from the same area in the late 1980s, as was another male beluga, Nanuq, who has since been transferred from the facility to Sea World in San Antonio.
The aquarium abandoned its direct-capture policy after it acquired Aurora, and now only accepts whales and dolphins that have been injured or born in captivity.
Beluga whales can reach lengths of 5.5 metres and weigh between 700 to 1,600 kilograms for an adult male. This is larger than all but the largest dolphins, but is small compared to other toothed whales.
