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. 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.