The Vancouver Aquarium is vowing to fight the new Vancouver Park Board bylaw which prevents it from bringing in new cetaceans.

"We will fight to the end to preserve our programs," said John Nightingale, long-time CEO of the aquarium.

Nightingale didn't rule out taking legal action, saying they were "keeping all options open."

The aquarium had been planning to open up a $20-million beluga habitat in 2019, which had been previously approved by the park board as part of a $100-million upgrade.

"In under five months we went from plowing ahead with a plan that was all approved, to going to whoop, you can't do any of that," he said.

Independent park board Commissioner Erin Shum, who was the only person who voted against the ban, said her decisions was partly due to the threat of legal action.

"Vancouverites, taxpayers, everyday residents are responsible here, we have to pay that, where that dollar could've gone to a community centre, or to that extra staff to clean up our parks," she said.

Passionate supporters both for and against the cetacean ban in Stanley Park were on hand for the Vancouver Parks Board vote on May 15. The Vancouver Aquarium's John Nightingale addressed supporters after the motion to ban passed. 1:21

Rescue services in jeopardy?

The aquarium also warned that the new bylaw would mean it can't rescue any cetaceans in need of rescue.

"If a whale is stranded this afternoon, your guess is as good as mine on what the DFO will say on if we can go rescue it," said Nightingale.

The Department of Fisheries and Oceans has to approve the aquarium to make a rescue, and then deems whether an animal is fit to be released or can be taken care of by the aquarium.

The aquarium normally cares for rescued animals at its offsite facility, which is not affected by the ban, before transferring those that can't be released back into the wild to the Vancouver Aquarium for long-term care.

In a statement, the DFO said each case is different and would be evaluated individually, but that "without the expertise of staff and facilities at the Vancouver Aquarium, we would not be able to rescue stranded or injured cetaceans. They are the only facility in Canada capable of responding to such incidents."

Opponents of a ban on cetaceans at the Vancouver Aquarium protest outside a Vancouver Park Board meeting on May 15, 2017. (Chrisy Corday/CBC)

"We actually couldn't believe that cooler heads or saner head wouldn't prevail, that they couldn't exempt animals who if they survived rescue need a long-term home," said Nightingale.

"Last night they defied logic and did that."

However, the Park Board said the aquarium rescues "mostly seals, not cetaceans", and believes that "the bylaw amendments are expected to minimally impact the aquarium's rescue and rehabilitation program."

"What they did voluntarily with orcas is they pick them up in a sling in the water and release it back," said Park Board Chair Michael Wiebe.

"What we're asking them to do is to treat other cetaceans like they do orcas"

The decision also leaves the future of five beluga whales currently on loan by the aquarium to U.S. facilities uncertain.

With files from Justin McElroy