At the mouth of what may be the world's richest salmon river, Greg Schuler is wading slowly through a massive school of dead fish, doing fisheries research the hard way.
A senior technician with the federal Department of Fisheries and Oceans, he is counting fish by hand, lifting each on a forked spear, then lopping off its tail with a razor-sharp machete to make sure it isn't tallied twice.
"It's all in the wrist," he says as he cuts a salmon in half with a flick of his blade, a movement he can repeat up to 3,000 times a day.
Some of the fish have spawned in the river and washed downstream, but others have died in Shuswap Lake, before laying their eggs.
"There are probably 10,000 to 12,000 here," he says, scanning the beach where each wave brings ashore another load of fish. "I would say most of these are pre-spawn mortalities. It's a mystery as to why it happens. They made it this far, but didn't have the energy [to continue]"
While thousands of tourists are wandering along the banks of the Adams River, marvelling at the sight of millions of bright red sockeye salmon jostling over the spawning beds, Mr. Schuler is taking inventory - doing crucial "gumboot science" to determine just how many fish have made the epic journey back from the Pacific, and how many have died before spawning.
The Fraser River system, which includes the Adams, is experiencing the biggest sockeye run in nearly 100 years, with an estimated 34.5 million fish returning. That stunning run brought a nearly moribund commercial fishery back to life, filling processing plants with a catch of 12 million fish, and it revitalized native communities which just last year, when the run collapsed to just 1.5 million sockeye, had no fish for ceremonial feasts.
While the Fraser's bounty is evident, the final count won't be known until after fisheries technicians have tallied the dead and determined spawning numbers, as Mr. Schuler and others are doing on rivers throughout British Columbia this fall.
There are concerns that some of the more than 30 different sockeye stocks in the sprawling Fraser system may be in trouble and that late runs - projected to be about nine million - may turn out to be much smaller than expected.
Also unknown at this point is how many will die along the way, becoming "pre-spawning mortalities." That phenomenon is not fully understood, although factors include disease, high water temperatures, unexplained delays in which the fish stay in the ocean longer than usual and injury from entanglement in fishing nets.
Whatever the final numbers are, it has been an amazing year for the Fraser system, and nowhere is that more evident than on the Adams, about 60 kilometres east of Kamloops, where five or six million fish are expected to crowd into a river barely 11 kilometres in length, creating a spectacle of nature that has become a global tourist attraction.
"The river looks great this year," says a smiling Mr. Schuler, as he works his way through the stinking pile of dead fish, a sight most tourists will shy away from once they catch the smell, which is so strong it sticks to your clothes.
"It's full of fish. It's fantastic to see," he says of the Adams, which experiences a big run every four years, triggering a festival known as the Salute to Sockeye, which is now in full swing a few kilometers upstream from the river mouth.
At the festival site, in Roderick Haig-Brown Provincial Park, Sonja Vernon-Wood, president of the Adams River Salmon Society, takes a deep breath when asked how the event has been going.
"Crowds. Big crowds," she says. And she's not just talking about the salmon.
The festival typically draws about 100,000. A good year sees 120,000 people. This year they expect to pass 150,000. Even mid-week the parking lot is full.
"The salmon are still coming in and so are the people," says Ms. Vernon-Wood, a realtor who is one of 100 local volunteers running the event.
On a nearby viewing platform, hundreds of people take pictures of tens of thousands of red and green sockeye salmon in a huge, undulating school along the shore. Cameras click endlessly as the afternoon sun illuminates the tail tips and dorsal fins breaking the surface.
"It's funny," says Ms. Vernon-Wood. "The fish come up and take care of themselves. But the people? They need organizing. We had 2,000 vehicles come in [on opening day] and if we didn't have all those volunteers there would have been chaos."
The society also organizes food service tents, picnic tables, an interpretive centre and trail signage, and puts in place dozens of portable toilets.
"The salmon are a real draw," says Ms. Vernon-Wood, who notes local restaurant sales and hotel bookings are up. "People come from all over the world. And we see thousands of school kids. We get people in wheelchairs and with walkers. You'd think this would be a difficult challenge, but they are determined to see the salmon. It's incredible."
Nearby, Jim McLellan, site manager, is directing traffic with a sign in the shape of a red salmon. "We had 32 school buses today. That's a record," he says as the last of the big yellow buses pulled out. "Sixteen to 18 buses a day is normal. This is a big year."
He says when the kids come piling out of the buses the first thing they comment on is the pungent smell in the air, even though it's not very strong in the parking lot, but it can be overpowering in places where there are piles of dead salmon.
"But when they come back nobody is complaining about the smell. They are just excited about what they've seen. It's remarkable the way this affects people," he says.
Jim Cooperman, president of the Shuswap Environmental Action Society, says the Adams River salmon run is one of the world's great natural events.
"There aren't many places where you can see a mass migration," he says. "There's wildebeest in East Africa, monarch butterflies [in Mexico] there's the caribou migration in the Arctic, but other than that there aren't too many places that are comparable."
"The Adams is a natural wonder, a treasure, and we should really be treating the salmon better," says Mr. Cooperman, who is worried about a housing development and marina proposed near the river mouth. "This is just one big return after many, many poor years on the Fraser. I think this will turn out to be just a blip unless we address all the problems. Climate change, deep ocean drift nets, habitat loss, fish farms - the list of threats to salmon goes on."
Mr. Cooperman adds that what is happening on the Adams River this year is seen as such a wonder only because most of the world has lost what once was common. "Don't forget, runs like this used to happen in rivers throughout the world, in Scotland, Norway, on the Atlantic coast, but those big runs are all gone now," he says.
Standing at the river mouth, Mr. Cooperman surveys the beach strewn with rotting salmon and smiles. To him, it smells good because the decomposing fish will enrich the lake with nitrogen and phosphorous, fertilizing the waters the young salmon will enter next spring.
"There is no waste in nature," he says. "All of these fish are needed to keep this miracle going."