We need to understand the extent to which floods further degrade fish habitat
The BC floods of 2021 blurred the distinction between fish habitat and human communities as contaminants from human activities washed unfettered into streams and rivers.
A version of this article was published by Vancouver Sun on December 8, 2022.
In November 2021, we viewed with alarm the unfolding flood disaster in southern BC. With government agencies dealing with the urgent public safety needs of the day, the health of fish habitat ranked low on the list of priorities. But as flood waters rose, the distinction between terrestrial and aquatic habitats blurred, salmon and sturgeon swam across farmer’s fields, and contaminants from human activities washed unfettered into streams and rivers.
We need to understand the extent to which floods (further) degrade water quality in fish habitat.
We at Raincoast Conservation Foundation responded to concerns expressed by the Sumas First Nation, the Indigenous-led Lower Fraser Fisheries Alliance and S’ólh téméxw Stewardship Alliance, and the Pacific Salmon Foundation by mobilizing an emergency response team to sample and analyze water samples from the flood-ravaged Sumas area. These entities would provide much-needed funding, alongside the federal Department of Fisheries and Oceans and the BC Ministry of Environment and Climate Change Strategy.
Our team collected samples from Sumas waterways following the floods, and submitted these for comprehensive contaminant analysis. With few pre-flood baseline data against which we could compare our findings, we ended up painting a picture of just how degraded fish habitat had become, with or without the intervention of the floods. And while many agencies have roles to play when it comes to water, the embedded silos designed to distinguish among ministerial mandates meant that salmon – those enigmatic fish to which we all ascribe value – risked falling between the cracks. Salmon must navigate contaminated corridors from their natal streams to the ocean and back again, transiting multiple regulatory and physical boundaries.
Our findings painted a bleak picture of the health of the waterways meandering through the remnants of Sumas Lake, drained nearly 100 years ago by the Barrowtown Pump Station. We found that cocaine, sucralose, Ibuprofen, the tire chemical 6-PPD Quinone, pesticides, hydrocarbons and perfluorinated substances were omnipresent in the area. The levels of several metals, pesticides and hydrocarbons in Sumas waters exceeded established Canadian Environmental Quality Guidelines – a total of 59 times. This meant that among those contaminants for which guidelines exist in Canada, a clear and present danger for salmon was lurking in these flood-ravaged waters.
And while guidelines serve to inform our understanding of risks to aquatic life, no guidelines exist for 77% of the contaminants that we sought to measure. This meant that we have no sanctioned means of determining whether the levels of such things as cocaine, sucralose, or 6-PPD quinone are below, at, or above levels of concern to salmon. With the derivation of new Environmental Quality Guidelines taking years, if not decades, this has the potential to make people think that the concentrations of these contaminants are safe for fish. Pharmaceuticals and veterinary drugs are designed to affect physiological systems in humans and livestock; pesticides are designed to kill unwanted weeds and pests; nutrients are designed to make plants grow. In fish habitat, the principles of comparative toxicology suggest that we have some reason for concern.
Prior to the arrival of settlers, the Sumas Prairie was a lake. A lake that quadrupled in size every fall as the rains fell. A lake that teemed with salmon, whitefish, sturgeon, freshwater clams, and migratory birds. For the Stó:lō peoples, the banks of this lake were not only home, but a vital means to access the lake’s resources.
The re-emergence of Sumas Lake killed farm animals, destroyed property, and threatened livelihoods. It has also provided us with an opportunity to take stock of what has become of fish habitat here, and in the wider Lower Fraser Valley. Fish today continue to eke out an existence in the waterways of the former Sumas Lake. But the migratory corridors of our prized salmon have changed, with dikes, flood control barriers and pumps channeling and draining their habitat.
As climate change looms large, the catastrophic BC floods of 2021 have reminded us of Mother Nature’s power, and provided us with an opportunity to consider questions worth posing: How can we identify contaminants of concern in fish habitat? Can we better protect fish habitat from excess nutrients, pesticides, hydrocarbons and domestic wastewater? Can we design a win-win green infrastructure agenda that protects both communities and fish habitat?
We can all do better – our future depends on it.
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Raincoast’s in-house scientists, collaborating graduate students, postdoctoral fellows, and professors make us unique among conservation groups. We work with First Nations, academic institutions, government, and other NGOs to build support and inform decisions that protect aquatic and terrestrial ecosystems, and the wildlife that depend on them. We conduct ethically applied, process-oriented, and hypothesis-driven research that has immediate and relevant utility for conservation deliberations and the collective body of scientific knowledge.
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