Vancouver Aquarium defends keeping whales and dolphins in captivity

I think we all know the arguments for and against - there i nothing new here. Personally, I'm wondering exactly what a Senate Bill is - I was under the impression (seemingly erroneous) that the Senate was for "sober second thought" i.e. they passed judgement on legislation sent to them by the House, but could not initiate legislation.  So how would this bill become law? 

Liberal Senator Wilfred Moore wants to phase out holding cetaceans in captivity across Canada. The Nova Scotia senator says the animals belong in the wild, not in tanks.

If passed, the legislation would directly affect operations at the Vancouver Aquarium.