When the Free Willy bill made an unexpected leap from the Senate on Tuesday, down the hall into the House of Commons, Elizabeth May was waiting with open arms for it to land.

The Green Party leader will sponsor the Ending the Captivity of Whales and Dolphins Act, which, after nearly three years in the red chamber, is finally forging ahead.

“I’m extremely pleased that we’re moving ahead,” May said. “The bill should have gone through when (original sponsor and former Liberal senator) Wilfred Moore was still in the Senate. But the fact that it actually happened is such a relief.”

The bill is expected to have its first reading on Monday.

“After all the time that was lost in the Senate, we didn’t want to waste any time in the House,” she said. “We’re determined to get this through before the election. It’s one of those things where good will on all sides will be required. We have a lot of non-partisan support, (so) I expect this to be a very different experience than the Senate.”

Tabled by Moore in December 2015, Bill S-203 aims to end the captivity of whales, dolphins and porpoises in Canada. It has a grandfather clause for those animals already in captivity and permits legitimate research, as well as the rescue of animals in distress. It would also ban the trade of reproductive materials, but nothing in the bill criminalizes the conduct of researchers.

Sen. Murray Sinclair took on sponsorship of the bill when Moore retired in January 2017 and introduced a clause to recognize Indigenous treaty rights and s.35 of the Constitution before the bill moved on from committee.

Throughout the legislative process, and up against a tide of Tory stalling tactics, May has pushed for the bill to pass in the Senate. The Conservative opposition was led by Sen. Don Plett, the party’s whip and caucus critic on the bill, who repeatedly used procedural obstruction to keep it from moving to a vote — a tactic that appeared to have the support of the party’s caucus.

In March, May sent an open letter to Conservative Party Leader Andrew Scheer, calling on him to wade in and tell his senators to stop blocking the bill. She said the stalling “disappoints the tens of thousands of Canadians who wish to see a vote on this bill, and reflects poorly on the national Conservative caucus.”

In June, she joined MPs from all parties — Conservative MP Michelle Rempel, Liberal MP Nathaniel Erskine-Smith, and NDP MP and Fisheries critic Fin Donnelly, along with Animal Justice and the Humane Society International — at a news conference to call on senators to stop playing games with the bill.

In September 2017, May also filed a complaint to the lobbying commissioner, raising concerns about possible past and ongoing breaches of the Lobbying Act related to Bill-203.

She called for an investigation into the conduct of Marineland, as well as the Vancouver Aquarium, both of which have been strong opponents of the bill.

At the time of May’s complaint, neither Marineland Canada nor any of its agents were registered under the Registry of Lobbyists. A search of the registry failed to produce any reported instances of the park’s lobbying of public office-holders related to the bill.

She also pointed to information that suggested reason for concern about the Vancouver Aquarium’s conduct. Neither it, nor its legal name (Ocean Wise Conservation Association), was registered under the Registry of Lobbyists at the time of her complaint. As well, there are no reported instances of it lobbying public office-holders in relation to Bill S-203.

Despite this, May offered evidence to suggest significant lobbying of senators by the aquarium has occurred.

“Both Marineland Canada and the Vancouver Aquarium are on the public record as opposing Bill-203, and both organizations generate significant revenue from the display of captive cetaceans,” she said in her complaint.

READ MORE: Lobbying complaint filed against Vancouver Aquarium and Marineland

May cited several reasons to suspect improper lobbying: social media posts (some of which have since been deleted), comments made by senators at committee, professionally prepared letters sent to all senators by both facilities, and a grassroots letter-writing campaign aimed at senators organized by the aquarium.

In a letter dated Sept. 27, 2017, from the Office of the Commissioner of Lobbying of Canada, Phil McIntosh, director of investigations, confirmed the complaint had been received. This past February, May’s office was told by a senior investigator it had been identified as a priority file. To date, there’s been no word from the office on the status of that investigation.

More than eight months after the complaint was filed, Marineland added its name to the federal lobby registry. The park’s lawyer, Andrew Burns, registered as a consultant on May 9.

Just before that, on April 11, Yaroslav Baran of Earnscliffe Strategy Group, who lobbies for Ocean Wise, made his first reported mention of the legislation on the lobby registry.

“Discussions with government officials: reasoned opposition to bill S-203,” his profile reads.

In a statement to CBC News, Marineland panned the Senate’s passing of the proposed legislation.

“Bill S-203 was not supported by the relevant ministries or the credible scientific community,” it said. “Sadly, it impairs legitimate scientific and research programs and is explicitly targeted to close Marineland.”

The park wants to see the bill halted in the House, as it said the debate has been “highly emotional, lacking in fact-based or science-based analysis, and mired in unnecessary conflict incited by radical animal rights groups from the United States.”

Those are claims Plett and Sen. Tom McInnis have repeated in the Senate, most recently on Tuesday.

At committee, however, in addition to researchers from the Vancouver Aquarium who spoke out against the bill, senators also heard from animal-welfare advocates and a slew of scientists, including: Dr. Hal Whitehead, a renowned marine biologist from Dalhousie University; Dr. Naomi Rose, a marine mammal scientist; Dr. Ingrid Visser, a marine biologist in New Zealand who has studied orca for decades; and Dr. Lori Marino, a neuroscientist and expert in animal behaviour. Each spoke in support of the bill, citing the harm that whales and dolphins suffer in captivity.

Between February and October of 2017, Bill S-203 spent months before the Senate Standing Committee on Fisheries and Oceans, which held more than 17 hearings and heard from more than 40 witnesses.

Echoing what many witnesses told senators at committee, May said that, in the wild, many cetacean species live their entire lives with their families called pods that may contain up to 100 members. Their pods have unique dialects, and they can travel up to 150 kilometres a day, reaching speeds of 45 km/h and diving more than 200 m deep. In comparison, an orca’s range in captivity is only 1/10,000th of one per cent the size of its natural home range.

For her, there’s no doubt science is on the side of this bill.

“There’s absolutely no question,” May said, noting that, without the backing of science, all the efforts to derail the bill might have succeeded.

“Keeping these highly evolved creatures in captivity is cruel, as is the entertainment value of watching whales and dolphins swim circles in concrete tanks. The sooner the House of Commons passes this bill, the better.”

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