On a cloudy summer morning off the north coast of British Columbia, biologist Charmaine Carr-Harris steers a black Zodiac toward a sandbar. Her smile suggests a leisurely outing, when in fact she is racing against unforgiving tides. Carr-Harris needs to collect and document samples of mud from a handful of geo-tagged locations before the incoming tide inundates the area, a 3-square-mile patch of sediment covered in streaky green eelgrass. If she’s nonchalant, the rising water will be waist-high before she gets back to the Zodiac. If she’s flat-out slow, it will threaten the rim of her chest waders, which would invite hypothermia, or worse. Grabbing her backpack, two plastic buckets, a bunch of Zip-lock bags, a waterproof notebook, handheld GPS, and an empty soup can, she hops out of the boat. “The science,” she says, “when you’re doing it, is actually quite haywire.”
Carr-Harris walks through the muck for nearly half a mile before two beeps signal that she has reached the first sampling site. Bald eagles land, take a few steps, and take off nearby, unperturbed by our presence as they search for crabs and other creatures exposed by the low tide. In the channel just north of the parked Zodiac, charter boats shuttle tourists to the fishing grounds of Chatham Sound in search of trophy halibut and salmon.
The salmon are why Carr-Harris is here, too. The sandbar is part of the nearly 600 square-mile Skeena estuary, a partially enclosed basin where freshwater from the giant Skeena River spills into the Pacific Ocean. “If you imagine an hourglass, think of one bulb as the river and its extensive network of branching tributaries, and the other as the open ocean,” says Matthew Sloat, Director of Science for the Oregon-based Wild Salmon Center. “The estuary is the narrow neck connecting the two, through which all the fish are funneled during their migration.” Carr-Harris is working with a team of scientists and local experts to investigate what types of organisms live on this near-shore feature of the estuary, known locally as Flora Bank. The samples they collect are providing a better understanding of the food available to juvenile salmon when they get here, and may in turn help settle one of Canada’s most contentious environmental debates.
After some quick note-taking, Carr-Harris kneels in the mud and proceeds to drive the soup can down into the sediment, twisting back and forth. When it’s fully submerged, she pushes her free hand in below it, forming a makeshift cover. As she lifts, the can and mud produce a suction-y sound: tthhhrrrrp.
The Skeena River is home to some of the strongest wild salmon runs anywhere on the planet, including all five species of Pacific salmon and some of the largest Chinook ever recorded. In good years, the runs can top 10 million fish. The river is the literal and figurative core of an inland watershed the size of Switzerland; indigenous communities have relied on the salmon and other resources of the Skeena for thousands of years; and it remains a crucial source of both calories and capital.
Soup cans full of mud and tiny critters could tip the fate of this place one way or the other.
Despite its ecological riches, British Columbia’s far north has struggled economically in recent decade. Even when oil was making hay for Canada, coastal towns of British Columbia were hurting, due to the steady decline of commercial fisheries and, more recently, a diminished timber industry. In Prince Rupert, population 12,500, local businesses have long since been shuttered or look like they’re about to be.
Into this grim financial picture comes the promise of LNG. Over the past three or four years, various proposals for liquefied natural gas export facilities have emerged, triggering a volatile mix of outrage and support. Pipelines would carry gas from the east and deliver it to locations here on the coast, where it would then be processed and loaded onto ships bound for the insatiable markets of Asia. At last count there were as many as 16 such proposals floated by various multinational conglomerates.
One of the projects, advanced by a group called Pacific NorthWest and led by Malaysia’s state oil company, Petronas, has been especially controversial. Processing natural gas for more efficient transport requires cooling it and condensing it to a liquid form. The cooling plant for Petronas’ $12 billion facility would be situated on Lelu Island, south of Prince Rupert and adjacent to Flora Bank. That plan does not sit well with many locals, especially some—but not all—members of the Lax Kw’alaams First Nation. A small group of protestors from the tribe has even set up a camp on the island in an Occupy-style protest. (Carr-Harris flies the flag of the Lax Kw’alaams off the back of her Zodiac so protestors don’t confuse her with gas-company contractors.)
The other flashpoint is Flora Bank itself. The Petronas proposal includes a bridge that would pipe liquefied natural gas from the facility on Lelu Island, across the Bank’s northern edge, to supertankers parked at a deep-water terminal farther offshore. Conservationists assert that the bank is fragile habitat for young salmon en route to the open ocean, and should therefore be left untouched. Development proponents have responded with what they claim is an environmentally sensitive design, and they argue that Flora Bank is just one small section of a massive estuary replete with salmon habitat. Yet as the debate intensified over the past few years, it became clear that there was scant data available to clarify the significance, or lack thereof, of this 2,000-acre dot on the map. Which means soup cans full of mud and tiny critters could tip the fate of this place one way or the other.
Skeena Estuary, British Columbia
Skeena Estuary, British Columbia
Proposed LNG facility
What is it about salmon? Their impact on forests, human history, economies, culture, cuisine, and angling is profound. Yet it’s even more than that—a mystique that has to do with home. Much like migratory birds and sea turtles, salmon find their way home. They do so from thousands of miles away and after years after having left, wending their way back to the rivers, small streams, and gravel beds where each first came into the world as a single sphere in a clump of orange roe. (They manage this feat by tapping into a combination of magnetic and chemical signals.) Once they reach their birthplace, the adults reproduce and then die. It’s one of those natural-world phenomena that make evolution sound less like a jumble of adaptations and more like poetry.
“How the fish find their way back has been an obsession” for generations of researchers, says Carr-Harris. And rightly so. Sheer wonderment aside, the study of reproduction—including where it happens and how the fish get there—is, by definition, critical for protecting fish stocks now and into the future.
But while these adult fish get all the attention, the journey of juvenile salmon—the teenagers—is no less astounding. To understand why, start with the inadequacy of the adolescence metaphor. With due respect to junior-high students struggling with all manner of emotional and physical turmoil, the transition from tiny freshwater fish (scientists call them parr) to ocean-going juvenile makes puberty look like a snap. A better analogy Carr-Harris says “is that of a person learning to breathe on Mars.”
Salmon have evolved a delicate regulatory system to ensure that, when in freshwater, they don’t lose too much salt from their tissues, while also not taking on too much water. In the ocean, the challenge is reversed: They must prevent salt poisoning and avoid becoming dehydrated. To go from a world where they must hang on to salt at all costs, to a world where they’re essentially drinking saltwater, the fish undergo a complete systems overhaul. This transformation involves what one group of Norwegian scientists describe as “coordinated developmental changes in biochemistry, physiology, morphology, and behavior…” with alterations “in lipid metabolism, osmoregulation, oxygen transport, buoyancy, growth, color, shape, rheotaxis [holding in position while facing into the current], and schooling behavior…” It’s as if the only thing connecting these freshwater organisms with the ocean-going fish they become is that we call them both salmon.
While a handful of other fish, like sturgeon and striped bass, also undergo this shift in habitat and physiology to match, only salmon transform ahead of time—before they hit salt. Years ago, when Carr-Harris had a job at a hatchery, she sometimes arrived in the morning to find dead juveniles on the floor of the facility. The fish were so completely compelled to get going downriver, or at least somewhere else, that they had jumped out of their tanks.
Scientists today are trying to tease out the underlying genetics—the triggers that control the salmon’s decision to head downstream. “What causes a fish to decide, ‘To hell with freshwater. I’m going to salt!?’” asks Jack Stanford, emeritus professor of ecology and director of the University of Montana’s Flathead Lake Biological Station. Attributes of the environment force the decision, but the fish “have to have the genes that allow the environment to push them one way or another.”
Juveniles undergo this transformation ahead of time, explains Stanford, because most big salmon rivers don’t end in broad estuaries where the fish could conceivably ease their way into ocean living. The rivers just empty, with only a small transition zone. That doesn’t mean, however, that out-migrating juveniles in the Skeena are ready for the blue water. They’re “probably freaked out when they encounter saltwater,” says Carr-Harris. The environment is foreign, turbid, and full of unfamiliar predators.
How exactly they respond to all this newness isn’t clear. “In general, we know surprisingly little about how salmon use estuaries,” says Wild Salmon Center’s Sloat. It is reasonable to surmise that young salmon spend some time in the estuary before venturing out into the Pacific, and that mini-habitats within the estuary, like Flora Bank, are especially important, hiding juveniles from predators in the sky and those lurking in deeper water. A 1972 study by Canada Fisheries identified Flora Bank as significant salmon habitat, and indigenous populations have long since touted its significance. But assumptions, no matter how reasonable or grounded in local knowledge, are not as conclusive as data, especially when multi-billion-dollar investments are on the line.
When the LNG proposals began drawing attention to the region, Carr-Harris found herself in the middle of an international smackdown. Born in Victoria, British Columbia, Carr-Harris moved to Prince Rupert when she was twelve. The girl with curly brown hair and wide curious eyes spent much of her childhood exploring the splendor of the region with her father, a seaplane pilot. One of her first summer jobs was counting fish on the docks in Prince Rupert, to earn money for college. Then she fell in love with biology—“here I am 20 years later, still counting fish,” she says. Now 40, Carr-Harris is in the field most days. When she isn’t studying the estuary and its inhabitants, she’s kayaking or fixing up the tiny cabin that she built in a spot so remote it’s only accessible by water at high tide.
In 2009, Carr-Harris took a research position with the Skeena Fisheries Commission, a quasi-governmental group that advocates for science-based fish policy. She began studying the role the estuary plays in the life cycle of juvenile salmon, looking at basic parameters like salinity, temperature, location, and food availability within small sections of the estuary. Some initial fish counts indicated that there were far more juvenile salmon in the small polygon outlining Flora Bank than in other parts of the estuary, a finding that contradicted reports commissioned by proponents of the LNG project.
Two years later, Jonathan Moore, an associate professor of aquatic ecology at Simon Frasier University, was putting together a research project focused on the Skeena and its estuary. He had learned that historical data on salmon in the region was sparse and felt there was an opportunity to inform the debate with sound science.
He had also experienced the Skeena years before. Moore grew up in Oregon but spent summers during high school driving with his family up the coast to Prince Rupert. From there they would “motor their boat up into Alaska and catch and eat crab, prawns, halibut, and salmon.” When he first saw the Skeena on one of those family trips, Moore was mesmerized. “Unlike where I grew up, there are no dams on the river. Unlike where I grew up, salmon are still an integral part of people’s lives.”
Moore, Carr-Harris, and local researchers have spent four years conducting habitat and population surveys of the Skeena estuary. The goal of the work was straightforward: determine which species of fish are there, where exactly they are, and whether they zip over Flora Bank and nearby spots on their way from the river to deeper water, or whether they stick around for a while.
What they found was an undersea Serengeti. As many as 300 million salmon come down the watershed every year, and many of them stop at—and rely on—Flora Bank to successfully complete their journey to the ocean.
What they found was an undersea Serengeti. As many as 300 million salmon come down the watershed every year, and many of them stop at—and rely on—Flora Bank to successfully complete their journey to the ocean. Their studies determined that juvenile salmon were much more abundant in and around Flora Bank compared with other areas in the estuary. When they compared fish numbers at Flora Bank with other eelgrass habitats in the Skeena estuary, they found that salmon were on average 25 times more plentiful. (The numbers differed depending on the species: sockeye were 72 times more plentiful; coho, 16 times more abundant, Chinook 15 times.)
The diversity on Flora Bank mirrors the diversity of the Skeena watershed as a whole, which is one of its most valued attributes. When people talk about huge salmon runs, they invariably mention Bristol Bay, Alaska. “It is huge,” says University of Montana’s Stanford. “But it’s almost all sockeye. The diversity in the Skeena watershed, of both species and the habitats they live in, adds to the overall resilience of the fish populations.” Summarizing some of these findings in a letter published in Science in August 2015 (“Juvenile Salmon Usage of the Skeena River Estuary”), Moore and his co-authors wrote that the area “supports particularly high abundances of juvenile salmon from more than 40 populations that are harvested in at least 10 First Nations territories throughout the Skeena watershed and beyond.”
To determine how long the juveniles were sticking around, the scientists examined the chemical signatures of their body tissues. Chemical signatures revealed whether the fish had been eating from a freshwater or saltwater menu, and for roughly how long. Although how long the juveniles hang around at Flora Bank varies by species, the scientists found that they typically spend weeks there, sometimes even more than a month, feeding and gaining strength.
Without Flora Bank, it’s unclear where the salmon would go or how well they would fare. This uncertainty is underscored by the fact that the fish go out of their way to get there. Instead of swimming with the current straight out the mouth of the river toward Chatham Sound, the young salmon cut hard right, to the north, through a narrow channel that leads onto Flora Bank. They are expending extra energy to get there, which means this spot doesn’t happen to sit along a migratory superhighway that could conceivably be rerouted. It means the fish have adapted to this particular habitat because of the survival advantages it confers. Picking up on the hourglass image, the fish swim their assess off just to reach a small corner of that already narrow neck between the watershed and the ocean.
Why? Eelgrass is certainly part of the answer. Back out on Flora Bank, the linguine-like grass is the dominant feature underfoot, and Carr-Harris says an estimated 50–60 percent of all the eelgrass in the estuary grows in this one spot. That plant food supports a host of organisms that salmon dine on—periwinkles, baby crab, micro-crustaceans, marine worms, and more. “And you can smell it, just being here, right?” says Carr-Harris. (It’s not really a question.) “It smells like decomposing animals. That suggests lots of biological activity,” which means great habitat for juvenile salmon. Meanwhile, predators like larger fish, eagles, mergansers, and other diving birds can’t easily see or get at them because they’re hidden in the wavy, dark grass.
Another clue to its significance is that Flora Bank isn’t even a typical sandbar. A veteran sedimentologist named Patrick McLaren recently conducted a study that involved some 2,400 samples of material from the bank. He concluded that this geological feature is a relic from the last ice age. Its large sand grains are not seen in other parts of the estuary, and the bank itself is held in place thanks to a delicate interplay between the tides and the river. The glacial history of the bank is interesting from an academic perspective, says Stanford, but the salient point “is the role it now plays in the productivity and life cycle of the Skeena salmon. It’s there. And the salmon are there!”
In a recent letter to the Lax Kw’alaams tribe, McLaren explained how his data indicate that “Flora Bank and the fish habitat that it supports are highly unlikely to survive the proposed LNG project.” Lose Flora Bank, or even harm it in some unforeseeable way, and the effect on the Skeena watershed—to say nothing of Pacific salmon stocks—could be catastrophic.
Header image of juvenile salmon in eelgrass on Flora Bank by Tavish Campbell
Footer image of lone sockeye salmon with a school of pink salmon by April Bencze