HALIFAX -- Rare "intimate" video that captures wild Atlantic salmon spawning in a Nova Scotia brook near a proposed gold mine should help persuade governments to reject the project, conservation groups said Wednesday.

The video shot last November was released in Halifax by the Nova Scotia Salmon Association, the St. Mary's River Association and the Atlantic Salmon Federation.

It shows a pair of wild Atlantic salmon preparing to spawn in McKeen Brook, a tributary of the St. Mary's River near the Cochrane Hill gold mine being proposed by Atlantic Gold, a subsidiary of Australian-owned St. Barbara.

"We hope these images, taken just a few hundred metres from a planned open pit gold mine, help people realize what's at stake," said Tom Cheney, who worked with photographer Nick Hawkins to make the video.

Cheney said the video shows the "beautiful, secretive, intimate and ancient ritual" of a female salmon flipping onto her side and using her tail to strike the pebbly bottom to make a pit for her eggs.

Kris Hunter, the Atlantic Salmon Federation's director of programs for Nova Scotia and Prince Edward Island, said the images are relevant to the company's application for environmental approvals.

He noted the Atlantic salmon has been recommended for listing as an endangered species.

The Canadian Environmental Assessment Act includes provisions calling for an assessment of whether a project affects fish, and the federal Fisheries Act prohibits adding substances to water that would degrade or alter it in a way that is "deleterious to fish or fish habitat."

Hunter said the film clearly shows the species is at a crucial point of its life in the Guysborough County river.

"We know there's stuff in that (gold mine) effluent and that it gets out into the environment," he said. "They (the company) deem that as an acceptable risk ... and we don't."

The company said in a statement that it appreciates the conservation efforts of the salmon federations and will review the information presented.

It notes the proposed mine will go before a federal-provincial environmental assessment process, and protection from any potential harm to salmon would have to be assured before the mine is approved.

The company says federal fisheries laws require that any water leaving the mine site would have to be "clean, strictly monitored, tested and regulated."

It also says the company's current mine in Moose River, N.S., has operated next to a lake and a wilderness area for more than two years and testing indicates that water and aquatic life haven't been harmed.

However, the salmon protection groups are saying they're unconvinced and argue the discovery of spawning grounds shows how crucial it is to avoid any form of contamination of the pristine waters in northeastern Nova Scotia.

"Over decades there has been an incredible amount of work put into the river," said Scott Beaver, president of the St. Mary's River Association.

"We have invested more than $1 million since 2014 to improve habitat for wildlife and recently received a $1.2-million federal grant to continue the work. This development could undermine everything we've done."

St. Barbara also wants to develop the Beaver Dam mine, next to the nearby West River at Sheet Harbour, and conservation groups have been raising objections to that proposal.

A spokeswoman for the province's Environment Department said in an email that the Cochrane Hill mine site is currently undergoing a joint federal and provincial environmental assessment which started in November 2018.

"Information on potential impacts to all species, including Atlantic salmon, must be provided in the environmental assessment document," the statement said.

The document is reviewed by federal and provincial experts, the public and Mi'kmaq of Nova Scotia.

Once the environmental assessment document is submitted, Nova Scotia Environment and the Impact Assessment Agency of Canada will receive public comments and submissions.

This report by The Canadian Press was first published Feb. 12, 2020.