A Montreal pond is rapidly drying and advocates are raising the alarm. Technoparc Oiseaux, a group representing the wetlands in the Saint-Laurent borough's Technoparc Montréal industrial park, said in a press release Monday that as much as 90% of the Heron Marsh could soon be dried up.

Technoparc Oiseaux said the REM has been tunnelling under the area to construct the branch of the light-rail network that will extend to Montreal-Trudeau Airport just to the south.

What's happening at the Montreal pond?

The organization specifically hypothesizes that what's happening is a process called "subsidence," which the U.S. National Oceanic and Atmospheric Administration (NOAA) defines as a "sinking of the ground because of underground material movement."

Technoparc Oiseaux also said a hole has been discovered in the marsh.

In its statement, the organization did not state definitively that the tunnel boring was the cause of the pond emptying, but said it has contacted the REM and the environment ministry about what it calls an emergency.

"A dried marsh will have catastrophic consequences for next year's fish population (spawning is likely to have already been seriously affected) and on the birds and other wildlife that feed on them," it said.

What is the REM's response?

The REM, for its part, said in a statement shared with MTL Blog that it's aware of the situation and wants to "reassure [...] citizen groups that the preservation of the wetlands in the Technoparc sector is of the highest importance" to the company.

It said it's investigating but that "all protocols have been put in place in collaboration with relevant authorities and respecting the highest standards" to protect the wetlands during the tunnel-boring project.

Technoparc Oiseaux is calling on officials to step in to help preserve the area.

"What will it take to get municipal, provincial, and federal authorities to value this last unprotected natural space on the island of Montreal, 215 ha of unprotected and non-fragmented wetland and greenspace north of Pierre-Elliot Trudeau Airport?" it asked.

"Where is the good stewardship of our vital natural spaces?"