Vancouver Park Board is banning the city’s aquarium from bringing in new whales, dolphins and narwhals — even those that are injured or rescued.

Animal rights groups supported the move, arguing that keeping cetaceans in captivity is cruel.

"There's substantial scientific evidence that cetaceans do suffer in captivity, and that outweighs the benefit of putting them on display for our entertainment," Vancouver Humane Society spokesperson Peter Fricker told the BBC.

The decision was taken in a vote on Monday night, despite Vancouver Aquarium’s claim that the move would be harmful rather than positive.

"It turns its back on some of the marine animals when they are in need," said CEO John Nightingale. He argued that the aquarium is the only one in Canada to offer a program that provides long-term care for rescued cetaceans that can't be released back into the wild.

The program has treated just six cetaceans in the last 50 years, but Nightingale said the research center has attracted marine life experts to Vancouver Aquarium.

The Park Board will support “the important and excellent work by Vancouver Aquarium staff and volunteers in the Marine Mammal Rescue Centre run at a facility outside of Stanley Park,” according to a statement released by the Vancouver Park Board on its website. “The proposed bylaw amendments will have a minimal impact on the program, as most of the rescued mammals are harbor seals. As confirmed by the Aquarium, cetaceans represent a tiny percentage of all of the marine mammals rescued since the program began.”

The chair of the Vancouver Park Board, Michael Wiebe, said the tide has turned when it comes to seeing whales and dolphins in aquariums. "I believe it is time to move on," he said. “The Park Board voted unanimously to amend the Park Control bylaw after discussions with aquarium staff, extensive public consultation, and a thorough review of marine science and best practices in aquariums around the world.”

The decision was prompted by an incident last year where two beluga whales died in the same week at the aquarium. An investigation found that they died from an unknown toxin, which could have been in their food.

The ruling reflects the Board’s decision to ban the import of all cetaceans into Vancouver parks, but acknowledges the need to address the current cetaceans already in residence at the Vancouver Aquarium. These animals will remain and are not affected by the ban.

Before the vote was officially held, the CEO and president of the Vancouver aquarium, John Nightingale, walked out the door without comment, but the aquarium communications staff released a prepared statement.

“For an enduring community organization founded by Vancouver residents, we feel the true essence of the topic was lost in the conversation,” the release said. “While we debate the value of caring for and studying beluga whales, there is no debating that we are experiencing the biggest mass extinction since the age of the dinosaurs.”

Nightingale praised the energy and ideas of dedicated marine researchers and biologists along with thousands of volunteers. “Despite recent challenges, my hope is that we all continue to do our part to slow down the impact we’re having on the planet.”