The Ecology Action Centre had said it feared Ottawa might ask for an increase in the catch, despite the species being under consideration for inclusion on Canada's Species at Risk Act.
But Kathryn Schleit, a spokeswoman for the centre, said Monday that the International Commission for the Conservation of Atlantic Tunas has decided during a meeting in South Africa to keep the quota at its level of 1,750 tonnes or less for the next year.
She said she hopes the decision allows the species, which has fallen to about one third of its 1970 population levels, to recover.
"There is a lot of rebuilding to be done and a lot of potential for the stock to be in better shape," she said from Cape Town, where she attended the meeting as an observer.
Faith Scattolon, the head of the Fisheries Department delegation, said it followed the advice of scientific experts with the commission.
She also said she is pleased scientific assessments of the bluefin tuna stocks will be looked at again at a June 2014 commission meeting in Canada.
"It will be a further opportunity ... to try to get at the sources of uncertainty and how we can improve information available to scientists," she said.
Last year, Canada's delegations stood alone at the commission meeting to ask for 250 more tonnes of quota, which drew criticism from environmental groups who said Canada was offside in efforts to conserve species.
Scattolon said scientific evidence supported her department's position at the time.
While pleased with the bluefin decision, Schleit says environmental groups remain concerned the commission didn't agree to bring in measures requiring fishing vessels to release porbeagle sharks they catch while harvesting other species.
She said she'd been hopeful Canada would support a European Union call for an end to this bycatch fishery, as Ottawa has recently ended a porbeagle fishery off its coasts.
Scattolon said Canada did not feel a measure ending the bycatch fishery was necessary based on scientific assessments of the shark stocks.
"We felt the harvest levels that are occurring in Canada will allow the population to rebuild," she said.