B.C’s wild salmon population is dwindling. What is going wrong and why? Kerry Banks follows the trail of the Fraser River and sees why these stunning species of salmon are struggling, and what efforts are being made to help them.
In B.C. and Yukon, 121 stocks of migratory salmon and trout have gone extinct in the last century, mostly due to urbanization and dams that eliminate spawning routes.
There are five species of Pacific Salmon–chinook, sockeye, coho, pink and chum; the populations of the first three are all far smaller than they used to be.
In 2005, the federal government adopted the Wild Salmon Policy which helped push conservation to the forefront of decision making. However many of its calls for action have been ignored.
Understanding what happens to the salmon is hard, because they undertake such a long journey, through many different conditions. Anything that happens out in the expanses of the deep, wide oceans is a mystery to scientists.
When the salmon move inland however and start their journey upstream, scientists are able to paint a better picture of what is causing a large portion of the decline.
What is Causing the Decline? “Overfishing, disease, pathogens from fish farms, habitat loss, the warming of the oceans. It’s death by a thousand cuts,” said one salmon expert.
Let’s look at these problems individually.
“Climate change is the most serious threat. It’s obvious,” said Scott Hinch, a professor of aquatic ecology and fish conservation at the University of British Columbia. Higher temperatures can prevent young salmon from developing and causes acidification of the water. Feeding grounds, energy levels of the salmon, even the route they take can all be thrown off by the increase in temperature.
Hatching New Problems – Hatcheries produce lots of new salmon, but one DFO officer compared them to “chemotherapy for the rivers.” Hatcheries in Russia, Japan, and Alaska are now pumping out as many as five billion salmon a year, most commonly pink or chum salmon. These fish eat smaller salmon and deplete food stores for migrating salmon before they can get there.
Losing Count – The DFO can’t be blamed for climate change, but according to a 2017 study in the Canadian Journal of Fisheries and Aquatic Sciences, the department does get a failing grade for its monitoring effects.
On the Farms – Pathogens and sea lice could be spreading from B.C.’s open-penned fish farms and infecting wild stock. This is not helped by incidents such as in 2017 when high tides, caused 300,000 Atlantic salmon to break free and compete with the local fish.
Swimming Up – Salmon are a key species for the B.C. river ecosystems, replenishing the nitrogen in the soil allowing trees along the river shore to grow. Without them, there is a knock-on effect throughout the environment.
There is cause for hope though. Some areas, like Vancouver’s severely polluted Still Creek, has seen the miraculous return of salmon for the first time in 80 years, back in 2012. Partnerships with local First Nations people, and looking to their methods of the past, may provide the key to saving the salmon’s future.
The salmon is a resilient species, but it is facing an upriver swim, and one we need to make easier for them.