Two reports released this week bring new insight into the state of salmon habitat in the Fraser Valley. One study, by the Earth to Ocean Research Group at Simon Fraser University (SFU), used time-lapse photography to understand how current flood protection infrastructure impacts salmon habitat. The second study, by the University of Victoria Environmental Law Centre (UVic ELC), commissioned by Watershed Watch Salmon Society, reveals an ongoing lack of oversight of salmon habitats behind dikes, despite the historical and ecological importance of these habitats for juvenile Fraser salmon.

Time-lapse photography of flood gates that open daily, July 11-16, 2014, Nathan Slough, Langley/Abbotsford.

Time-lapse photography of flood gates that open daily, July 11-16, 2014, Nathan Slough, Langley/Abbotsford.

Rebecca Seifert is the lead author of the SFU study, released today by the Journal of Estuaries and Coasts.

“Most tributaries and side channels to the Fraser River are behind dikes, with floodgates controlling how and when water passes through,” says Seifert. “These floodgates are installed to protect homes and farms from flooding, however, when they are closed, they also bar native fish from accessing valuable habitat.”

Seifert used time-lapse photography to document how often these floodgates were open and closed. For those waterways that had floodgates open more often, there was higher native fish biodiversity and better oxygen levels.

“This study shows that opening the floodgates more often would improve conditions for native fish, including salmon.”

Lina Azeez, campaigner for Watershed Watch Salmon Society, says the solution is to implement flood management plans and corresponding policies and bylaws that consider the whole ecosystem.

“We want municipalities, who often own and maintain flood infrastructure, to build it to be fish-friendly,” says Azeez. “The technology exists. It’s the will that’s lacking.”

While this solution sounds straightforward, figuring out who is responsible for guiding this change has proved to be more challenging.

The UVic report, also released this week, confirmed that while local, provincial and federal levels of government all have some responsibility for healthy salmon habitat, there is little ongoing oversight of fish habitat behind dikes, or fish passage through flood structures.

“No one is effectively overseeing the more than 1,400 km of salmon habitat behind floodgates in the lower Fraser Valley,” says UVic ELC’s Acting Executive Director and law professor Deborah Curran. “It’s quite startling to see that the fish-related impacts of the over 155 pump stations and floodgates are not subject to systematic ecological review or monitoring.”

Watershed Watch Salmon Society is contributing to a regional strategy dealing with the challenge of upgrading aging flood infrastructure. They aim to make fish-friendly infrastructures the new standard.


Link to SFU research.

Link to ELC UVic legal review