You can’t ‘offset’ extinction of Fraser River Chinook salmon

Globally, only 15.5% of the world’s coastal regions remain ecologically intact. In British Columbia, the Fraser River Estuary has already lost 85% of its flood plain habitat, and more than 100 species that live there are at risk of extinction. Now, they face another threat. 

The Vancouver Fraser Port Authority (the port) wants to double the size of its shipping terminal at Roberts Bank in the Fraser Estuary. A growing body of evidence indicates that habitat offsetting cannot counteract the serious effects the massive Terminal 2 expansion will have on the habitat of threatened and endangered species.  

The federal government’s environmental assessment of the Terminal 2 project was clear and unambiguous with regard to Fraser Chinook salmon and southern resident killer whales. In a 613-page 2020 report, the Impact Assessment Agency of Canada identified that T2 would result in negative and ongoing effects to juvenile Chinook salmon populations from the Lower Fraser and South Thompson Rivers. These Chinook populations are the primary fish that southern resident killer whales forage on in the summer months. The agency concluded that the loss of these Chinook salmon for southern resident killer whales would be regional in extent, permanent in duration, irreversible and continuous. Read that again, continuous and irreversible. 

For the already nutritionally-stressed southern resident killer whales, this does not bode well. Coupled with this loss of prey, the project would also subject the whales to an increase in underwater noise. The agency concluded that this would result in a significant adverse cumulative effect on these whales. Between an increase in underwater noise and the declining abundance of Fraser Chinook that are anticipated from Terminal 2, it is probable that these conditions would increase their likelihood of extinction. 

In the same report that outlines the significant and irreversible impacts Terminal 2 will have on Chinook salmon and southern residents, it also discusses “offsetting” these negative effects. But can you compensate for permanent impacts on species that are already at risk of extinction? 

Habitat offsetting emerged as a strategy to reduce the negative effects to biodiversity that result from development. However, due to a lack of evidence demonstrating the effectiveness of offsetting, there have been significant concerns regarding its use to make up for destroyed habitat. The problem with habitat offsetting is that you cannot “replace” nature. 

In the Fraser River Estuary, a 2016 study found that among offsetting sites implemented between 1983 to 2010, only 33% of sites attained their intended biological function and goals. The study found that even after three decades, time did not make a positive difference in meeting these objectives. 

In the agency report, it was clearly stated that the port’s proposed plan to offset a total of 72 acres is not sufficient to compensate for the loss of habitat that will occur from the 437 acres of concrete poured into the estuary. For Chinook salmon, the report stated it is “unlikely that there are sufficient offsetting opportunities for Chinook in the project vicinity to compensate for the lost productivity.” In other words, the agency suspects this habitat is irreplaceable.

In December 2021, the port provided an updated habitat offsetting plan to the newly elected Minister of Environment and Climate Change, Steven Guilbeault. The updated information proposes mitigation projects that make a suite of assumptions, assign subjective values to habitat quality and use models to predict whether these projects work. However, there is no evidence indicating that these mitigation projects will be effective in compensating for the negative effects to Chinook salmon and southern resident killer whales. Speculation from the proponent’s modeling does not meet the standard of evidence-based mitigation.

On Feb. 7, a group of renowned scientists with expertise on Chinook salmon, southern resident killer whales and the Fraser Estuary co-authored a letter to Minister Guilbeault that outlined the biological rationale for rejecting Terminal 2. They stated that the proposed mitigation measures by the port are insufficient to offset the damages that will incur to habitat, and if Canada is committed to recovering at-risk species the project must be rejected. 

The bottom line is that you cannot offset extinction. If the development of Terminal 2 pushes southern resident killer whales and populations of Fraser River wild salmon into extinction, can it ever be worth it?