The Vancouver Park Board’s long-running debate on cetacean captivity has seemingly been brought to its conclusion after the body voted unanimously to end the practice of keeping whales, dolphins and porpoises at Vancouver Aquarium.

A previous ruling by the Park Board banning the breeding of captive cetaceans collapsed in November 2014 when it tried to push a ruling through at the last minute.

Following the sudden deaths of the aquariums two beluga whales last November, Park Board chair Sarah Kirby-Yung – former vice-president of communications for the aquarium – said that the events justified a vote by city residents on continued whale captivity in the region.

Following two nights of debate over the matter, councillors vote to “bring forward for enactment by the Board an amendment to the Parks Control bylaw to prohibit the importation and display of live cetaceans in Vancouver parks.” The amendment for enactment will be issued by 15 May 2017.

“I know our team will continue to fight for nature long after this conversation has ended, and I’m immensely proud to be part of a team that reminds me daily of why people around the world look to Vancouver Aquarium as a beacon for world conservation,” said Vancouver Aquarium CEO John Nightingale, speaking after the vote.

The decision is a heavy blow for the aquarium, which recently announced a CA$100m (US$76.1m, €72.2m, £61.3m) 12-year expansion. At its heart, the expansion features a larger enclosure for its Arctic beluga habitat, with a new water filtration system and improved security measures.

The aquarium last month announced a new 12-year beluga conservation programme centred on a small group of non-breeding beluga whales, which would be brought back to the aquarium from peer accredited institutions to participate in an expanded Marine Mammal Research Programme. By the end of 2029, the aquarium was planning to permanently end its display of beluga whales.

The aquarium could still appeal the decision to the province, which could nullify the decision through an amendment to the Vancouver Charter. If that happened the aquarium would be able to resume its display of Cetaceans in its home of Stanley Park.

The aquarium owns six belugas, four of which reside at SeaWorld in Orlando, with the remaining two calling Georgia Aquarium home. Including the recent deaths, the aquarium has lost three belugas since 2015, with a beluga – loaned to Orlando SeaWorld from Vancouver Aquarium – dying after an encounter with other animals in its tank in February 2015.

The aquarium currently has three cetaceans on display – a harbour porpoise, a Pacific white-sided dolphin and a false killer whale.