Wild Salmon Migration Monitoring

Pacific salmon are born in freshwater, migrate out to the ocean, and then fight their way back — often hundreds of miles — to spawn in the very stream where they hatched. After spawning they die, and their bodies feed the river that raised them. That return is the heartbeat of British Columbia’s watersheds: it feeds bears, eagles and orcas, carries ocean nutrients far inland, and anchors the culture and economy of the communities along the water.

The Pacific salmon life cycle — courtesy of the Pacific Salmon Foundation.

Knowing how many fish actually make it back is the single most important number in salmon management — escapement targets exist to guarantee enough survive to spawn. But counting them by hand, river by river, season after season, simply does not scale. Together with the Pacific Salmon Foundation, the Wild Salmon Center, Lumax AI and Simon Fraser University, we built SalmonVision — a multi-sensor system that counts and identifies migrating salmon automatically, around the clock.

We must take every step in our control now as climate-change related trends will make things more difficult for salmon populations in the years ahead. This demands urgency for Pacific salmon and for the 130+ species, including grizzlies, orcas and eagles, that depend on Pacific salmon.

– Pacific Salmon Foundation

Sensors watch the river, a computer-vision model detects and identifies each fish, and individuals are tallied into a count managers can act on.

Wild salmon holding in the current, filmed by an underwater monitoring camera.

Why wild salmon matter

Salmon are a keystone species: pull them out of the picture and the whole web around the river begins to fray.

Salmon under pressure

Wild salmon in BC and around the world are squeezed from every side. Habitat is lost to development and logging; dams and culverts block migration routes; unsustainable fishing thins the run; pollution degrades the water; and a warming climate raises river temperatures and scrambles the timing of the migration. Each pressure compounds the others — and you cannot manage what you cannot measure. That is why an accurate, continuous count is the foundation beneath every other conservation decision.

How SalmonVision counts a run

At the core is a computer-vision model that watches the river and does the work a human reviewer used to do by hand — frame by frame, fish by fish.

Each frame runs through the model, which boxes every fish and labels its species with a confidence score.

Three ways we count

No single sensor works in every river, so SalmonVision pairs the same vision pipeline with three complementary ways of seeing the water.

In the field

Three complementary sensors, one shared vision pipeline — switch between them to see each in action.

In the web app

Every detection flows into a review app, where counts are tallied on a timeline and a person can confirm the model’s work — turning continuous footage into trustworthy, exportable reports.

In the review interface, each fish is tracked, boxed and classified by species for a reviewer to confirm.

Reviewing detections in the app — bounding boxes, species labels and a running count on a timeline.

The species we recognize

SalmonVision identifies the main Pacific salmon species as they pass the camera — not just a single overall fish count.

Chinook The largest Pacific salmon — often ~30 lb, up to 100+ ＋ tap for more Chinook The largest Pacific salmon and the prized “king” of the runs — typically around 30 lb but capable of topping 100 lb, and 40–60 inches long. ↩ tap to flip back Sockeye Prized red-fleshed salmon — 5–12 lb ＋ tap for more Sockeye Slim, streamlined and brilliantly coloured. Culturally vital to many First Nations; matures around age four at 5–12 lb and 20–28 inches. ↩ tap to flip back Coho Adaptable “silver” salmon — 8–12 lb ＋ tap for more Coho A highly adaptable “silver” salmon found in rivers and streams across North America. Usually 8–12 lb and 18–24 inches long. ↩ tap to flip back Chum Second-largest salmon — 12–15 lb ＋ tap for more Chum The second-largest Pacific salmon after Chinook. Typically 12–15 lb and 35–45 inches long. ↩ tap to flip back Pink Smallest and most abundant — 3–11 lb ＋ tap for more Pink The smallest and most abundant Pacific salmon in BC, and the least vulnerable to extinction. Usually 3–11 lb and 18–24 inches. ↩ tap to flip back Steelhead Sea-run rainbow trout — can spawn more than once ＋ tap for more Steelhead Sea-run rainbow trout that, unlike other Pacific salmon, can spawn more than once. Most are 8–20 lb, though some top 30 lb and 45 inches. ↩ tap to flip back

Beyond the salmon above, the system also recognizes Bull Trout, Rainbow Trout, Whitefish, Shiner, Pikeminnow, Jack Chinook, Lamprey, and Cutthroat Trout.

Built with First Nations

First Nations across the North and Central Coast of British Columbia are at the heart of this work — contributing data and expertise to train the models, and leading their use for salmon stewardship within their own territories, alongside the research and conservation partners who sustain SalmonVision.

Conclusion

A wild salmon migration monitoring system turns the hardest, most tedious part of conservation — counting — into reliable, continuous data. With accurate numbers in hand, managers can set fishing quotas, prioritize habitat restoration, hold infrastructure to account, and give communities a transparent picture of the runs they depend on.