VANCOUVER — In a first for North America and possibly the world, the Vancouver Aquarium has successfully bred Arctic cod in captivity.

Within weeks an estimated 500 to 600 juvenile cod will be on display for the public, said Danny Kent, the aquarium's curator of B.C. Waters.

"We're super happy about it," said Kent. "The Arctic display is there to educate the public and it's more cost-effective to replace our display animals (ourselves) when they pass on."

Kent said it's also an opportunity for researchers to come to Vancouver to study Arctic cod, who are a keystone species in the Arctic ecosystem,

"Everyone is starting to get more interested in the Arctic because of global warming and oil exploration so their survival is important. Arctic cod is such a key to other species in the Arctic food chain. Arctic char, seals and belugas all depend on Arctic cod for their food."

He said in the last three years biologists from the aquarium have gone to the Arctic four times and collected a couple of dozen Arctic cod adults. It was from these fish marine biologists, over the past six months, were able to breed the cod now in the juvenile stage.

"Rearing Arctic cod is a delicate and intensive process, and the early development stages are critical to the livelihood of the cod," said Kent. "The Arctic cod larvae and eggs are extremely fragile and require meticulous and constant expert care to thrive."

He said under a previous curator the aquarium tried to breed Arctic cod in the late '80s and early '90s but was unsuccessful. Marine biologists resumed their effort in 2009.

Kent said he believes one of the reasons why they were successful this time is the aquarium now has a better water system to hold the fish and get the right quality of food to them when they were in the larvae stage.

"Arctic cod instead of laying eggs in a ball scatter them and they free float in the super cold water. They almost look like an embryo — a ball of yolk with a tail floating around (when hatched). We were able to get them eating well and developing. We're in the clear now. We can truly call them juveniles. The fish look like miniature Arctic cods," he said.

He added opportunities to study Arctic cod are extremely rare because of their remote natural habitats and the extremely challenging water temperature and conditions in the Arctic.

The species lives in northern Canada, including the Beaufort Sea, the Arctic Archipelago, Hudson Bay, Baffin Bay, and along the coasts of Labrador and Newfoundland. They spend approximately nine months a year under the ice, making it challenging for scientists to collect information on their life cycle and basic requirements to live.

The aquarium's Arctic Connections exhibit opened in 2009 and is the only North America aquarium to have Arctic cod on display.

kpemberton@vancouversun.com