Salmon have been swimming in Pacific Northwest waters for at least seven million years, as indicated by fossils of large saber-tooth salmon found in the area. During that time, they’ve been a key species in intricate, interconnected coastal ecosystems, bringing nitrogen and other nutrients from the ocean and up streams and rivers to spawning grounds, feeding whales, bears and eagles and fertilizing the magnificent coastal rainforests along the way. For as long as people have lived in the area, salmon have been an important food source and have helped shape cultural identities.

But something is happening to Pacific coast salmon. This year, B.C.’s sockeye salmon run was the lowest in recorded history. Commercial and First Nations fisheries on the world’s biggest sockeye run on B.C.’s longest river, the Fraser, closed. Fewer than 900,000 sockeye out of a projected 2.2 million returned to the Fraser to spawn. Areas once teeming with salmon are all but empty.

Salmon define West Coast communities, especially Indigenous ones. The West Coast is a Pacific salmon forest. Today, salmon provide food and contribute to sustainable economies built on fishing and ecotourism. West Coast children learn about the salmon life cycle early in their studies.

Salmon migrations, stretching up to 3,000 kilometres, are among the world’s most awe-inspiring. After spending adult lives in the ocean, salmon make the arduous trip up rivers against the current, returning to spawn and die where they hatched. Only one out of every thousand salmon manages to survive and return to its freshwater birthplace.

So what’s going wrong? Climate change is amplifying a long list of stressors salmon already face. Sockeye salmon are sensitive to temperature changes, so higher ocean and river temperatures can have serious impacts. Even small degrees of warming can kill them. Low river flows from unusually small snowpacks linked to climate change make a tough journey even harder.

Oceans absorb the brunt of our climate pollution — more than 90 per cent of emissions-trapped heat since the 1970s. Most warming takes place near the surface, where salmon travel, with the upper 75 metres warming 0.11 C per decade between 1971 and 2010. Although ocean temperatures have always fluctuated, climate change is lengthening those fluctuations. A giant mass of warmer-than-average water in the Pacific, known as “the blob”, made ocean conditions even warmer, with El Niño adding to increased temperatures. Salmon have less food, and face new predators migrating north to beat the heat.

Beyond creating poor environmental conditions for salmon, climate change increases disease risks. Warm conditions have led to sea lice outbreaks in farmed and wild salmon, and a heart and muscle inflammatory disease has been found in at least one farm. Scientists researching salmon movement through areas with farms are finding wild fish, especially young ones, with elevated parasite levels. Diseases that cause even slight deficiencies in swimming speed or feeding ability could make these marathon swimmers easy prey.

Some question whether wild salmon will remain a West Coast food staple. For the first time, the Monterey Bay Aquarium’s Seafood Watch program has advised consumers to avoid buying chinook and coho from four South Coast fisheries. Researchers also predict changing conditions will drive important food fish north by up to 18 kilometres a decade.

Disappearing salmon don’t just affect humans but all coastal ecosystems and wildlife. Eighty-two endangered southern resident killer whales depend on chinook salmon to survive. As chinook stocks go down, the likelihood that these whales could become extinct goes up.

Although the federal government has committed to implement recommendations from Justice Bruce Cohen’s inquiry into Fraser River sockeye and to follow the Wild Salmon Policy, reversing this dire situation will take widespread concerted and immediate action. A weak provincial climate plan that fails to meet emissions targets and acceptance of new ocean-based fish farm applications won’t help wild salmon. We need to move fish farms out of the water and onto land.

Salmon are resilient and have survived ice ages and other challenges over millions of years. They’ve survived having their streams paved over. They’ve survived toxins dumped into their environments. The question is, can they — and the ecosystems that depend on them — survive climate change and fish farms and all the other stressors humans are putting on them?

Written with contributions from David Suzuki Foundation senior communications specialist Theresa Beer.

Learn more at www.davidsuzuki.org.

The Narwhal’s reporters are telling environment stories you won’t read about anywhere else. Stay in the loop by signing up for our free weekly dose of independent journalism.

Gary Krause was mystified by an unusual fish he caught in his trawl net off B.C.’s Pacific north coast in October. It was a Pacific electric ray, named for a pair of organs behind its head that can knock a human adult down with a powerful shock.

Trawl fishery records show 88 of these rays in B.C. waters since 1996. Although an electric ray was first recorded off Vancouver Island’s west coast in 1928, nearly a quarter of the more recent sightings came from 2015 alone.

Fishermen like Krause, who worked an astounding 4,000 days at sea over the past 35 years, are often the first to observe the beginnings of fundamental ecosystem shifts. In 2008, he also identified the first ever brown booby, a tropical seabird, in Canada’s Pacific waters.

Why are creatures like electric rays, which prefer warmer southern California or Baja waters, turning up with greater frequency further north?

Unlike land temperatures, which constantly fluctuate, ocean temperatures are usually stable, with virtually no daily changes, little seasonal differentiation and only minor shifts over decades. Most marine animals prefer a narrow temperature range and move only in response to changes.

Short-term oceanographic events, such as El Niño and the Pacific “blob” — an enormous area of unusually warm water in the North Pacific — demonstrate that while oceans may be relatively stable, they aren’t immune to temperature shifts. These phenomena explain the appearance of unexpected species off B.C.’s coast over the past winter, including a Guadalupe fur seal, green sea turtle and Risso’s dolphins.

Higher water temperatures are also changing the relative concentrations of microscopic, occasionally toxic algae.

While these marine oddities don’t necessarily indicate a full-scale ecosystem shift, they may be signs of what to expect as the planet warms. Shorter-term phenomena correspond with longer-term oceanographic changes around the world. These changes promise to fundamentally alter the cast of characters in marine ecosystems before we’ve had the opportunity to adequately study them.

Climate change is pushing more species of fish closer — and faster — to the cooler North and South poles than similar climate-provoked wildlife movements on land. Fish are moving an average of 277 kilometres every decade and phytoplankton are speeding along at 470 kilometres. Land-based wildlife are inching along at an average of six kilometers a decade.

These shifts are bringing together species that have never had contact before, introducing new predators that could result in regional extinctions. In addition to moving, phytoplankton, which produce half the world's oxygen and support most ocean life, have been declining dramatically over the past century, an average of one per cent a year.

Sea levels are also rising quickly because of climate change. Over the past two decades, global levels have risen more than twice as fast as in the 20th century. As water warms up, it expands.

Thermal expansion in warmer ocean waters has been the greatest contributor to global sea level rise over the past century — although rapid melting of glaciers, polar ice caps, and Antarctic and Greenland ice sheets is also a factor.

Higher ocean temperatures also stress coral reefs, which then release algae, causing the corals to bleach and often die.

Australia’s Great Barrier Reef just experienced its worst bleaching ever, with the Great Barrier Reef Marine Park Authority reporting that half the coral in the northern parts of the reef were dead, according to a Guardian article.

Along with environmental impacts, warming oceans will create economic insecurities for industries such as fisheries. One study predicted a nearly 50 per cent decline in B.C. First Nations’ catches for culturally and commercially important fish by 2050.

We can help marine life by reducing greenhouse gas emissions to keep global average temperature increases below the 1.5 C goal set out in the December Paris Agreement. Well-monitored fisheries, like those in British Columbia, will become essential data-collection points for understanding shifting marine environments.

Although it’s difficult to reverse temperature and other oceanographic changes that climate change has already set in motion, we may be able to lessen the impact through habitat protection, strong fisheries management and robust scientific monitoring.

The Pacific electric ray is just one of many marine canaries warning us of changing ecosystems. We’d be wise to listen to these signals.

Written with contributions from David Suzuki Foundation senior research scientist Scott Wallace.

Learn more at www.davidsuzuki.org.

Image: Pennington Marine Science Center/Youtube.

The Narwhal’s reporters are telling environment stories you won’t read about anywhere else. Stay in the loop by signing up for our free weekly dose of independent journalism.