Death of a Salmon: How Declining Salmon are Affecting the Environment

Humans have also benefited in countless ways from the salmon swimming in our rivers. From being a healthy and dependable food source to the enriching timber and soil needed for building civilization, we may, in fact, owe much of our very existence and continued prosperity to the salmon swimming in our rivers. Yet, at this very moment, we’re standing on the brink of losing it all.

Losing a Keystone Species

Salmon populations across the Pacific Northwest are rapidly disappearing, with a few isolated populations in danger of becoming completely extinct. This is a major concern, not only for obsessive salmon anglers who depend on the fish for both food and sport, but also for the community at large as the salmon’s presence in a river affect everything around it.

“Salmon are the ultimate keystone species,” fisheries scientist Gary Marston, who works as a scientific advisor for Trout Unlimited, said. “The loss of salmon for these watersheds affects the entire community and the ecosystem. From the trees, which get nitrogen from the fish after they spawn and die, to the otters, bears, bobcats, raccoons, eagles, and hawks that rely on the fish for food. It’s an entire community effect, and all these things suffer when salmon are not abundant.”

The loss of salmon has a ripple effect, one that spreads to every tiny corner of the salmon’s world and causes a chain reaction of loss. The rivers and streams that salmon migrate to are generally very infertile, making them places where life tends to struggle, so they depend on the nutrients that salmon bring with them from the ocean. Without the fish, water-borne insects like stoneflies and mayflies that rely on salmon for food don’t get the same nutrients that they had in the past, which makes the insects smaller and their hatches sparse. In turn, the animals that eat the bugs, such as birds and bats, begin to struggle, and so it goes on up the line.

“I’ve read several studies about areas where the lack of salmon is affecting songbirds,” Marston told MeatEater. “Their body conditions grow worse in areas where there were suddenly no salmon or even declining salmon. They also have smaller clutches of eggs because they lack the nutrients from the insects that feed on dead salmon. But it goes so much further than birds and bugs. These ecosystems have evolved in tandem with the salmon, so we're talking about everything from microscopic algae all the way up to vast old-growth forest communities where healthier and larger trees are being depleted by the lack of nitrogen and other minerals provided by the salmon.”

This trickle-down effect extends beyond just the lack of salmon in the rivers and streams that they spawn in and is even being felt out on the open sea. Dozens of marine predators such as sharks, seals, orcas, and even lamprey feed on the fish during their time in the salt water and their loss is being felt. The Southern Resident killer whale population, which once thrived in the waters between British Columbia and California, is an example of this as their population has dropped alarmingly in recent years, with the whales being added to the endangered species list in 2005. Salmon are an essential part of the whale’s diet, and the drop in both the salmon population and their overall size has been one of the biggest contributing factors to the orca’s collapse.

A Salmon Free Fishery is An Empty Fishery

It does seem obvious that the people suffering most from the loss of salmon are, of course, salmon fishermen. Both anglers who love hooking these giant and powerful fish on rod and reel, as well as those in the commercial industry who depend on salmon returns for their livelihood, are feeling the loss of the fish already. However, even if you’re not a salmon angler and prefer fishing for other species, the salmon’s disappearance can still be felt as they influence so many of the other fish around them.

“Without salmon in these waters, you won’t have steelhead or trout,” Pacific Trout Unlimited Communications Director Greg Fitz said. “The species are just so dependent on one another, with trout and steelhead smolt feeding on both the salmon eggs and the insects that feed on the dead salmon. Without the salmon, all the effort and time and money that we’ve put into restoring other species like steelhead will have been for nothing.”

The symbiotic relationship between salmon and other gamefish has been well documented, but many anglers don’t realize just how deep these relationships go. In many cases, other fish species are almost entirely dependent on salmon being in the river, and losing them could devastate many world-class fisheries.

“Throughout the different studies I participated in, we found a lot of connection between rainbow trout populations and salmon,” Marston told MeatEater. “Salmon eggs make up a big part of their diet, to the point where we’ve found up to 900 eggs in one rainbow, and salmon eggs are about 3 times more energy-rich than insect larvae, which allows fish to grow larger.”

But the presence of salmon doesn’t just mean bigger fish, it also ensures the survival of more fish.

“In addition, we saw juvenile survival rates of rainbows increase by a huge margin compared to where there were no salmon,” Marston said. “In places where pink salmon come into a river, we found that 30% of the food source for juvenile trout, steelhead, and salmon are actually sea lice falling off the pinks. It’s these little things that can push the fish over the edge, give them a little bit of edge, and help them survive. In short, where the salmon were, we saw other salmonids thrive.”

However, on other rivers that Marston and his team visited, the results were not always so bright. On one river, they saw firsthand what can happen to other fish when salmon runs disappear.

“By contrast, one of the most interesting things we found on one particular river we studied was that summer chum salmon actually declined pretty significantly during the study,” Marston said. “We went down from a healthy run to about 100 to 150 salmon per mile. This is not a large population and a huge drop from what it had originally been. By the end of that study, we were unable to capture enough trout to even do a population estimate. The trout population had declined that much because the salmon just weren’t there.”

Even in areas where salmon aren’t completely lost, the style and tradition of salmon fishing are often forced to change.

“I grew up in Alaska, and fishing in Alaska meant we were targeting big trout and char with eggs and flesh flies,” salmon biologist and avid angler Haley Ohms said. “When I moved down to the lower 48 and started chasing trout around Oregon and Washington, those egg and flesh flies simply don’t work because those big resident salmon just aren’t around in the same numbers. It really drove home the losses we’ve experienced in the Pacific Northwest because that sort of fishing used to exist here.”

The Fight for Fish

Dropping salmon populations are nothing new, as salmon stocks have been in decline for nearly 180 years. Since the 1850s, logging, mining, and overfishing combined with flooding and general mismanagement have led to many salmon stocks falling. However, in the last 50 years, the construction of dams, lack of understanding of salmon behavior, and climate change have seen some runs reduced to less than 10% of their historic numbers, and some populations have even disappeared altogether.

Now, it’s not all doom and gloom as many of the struggling salmon runs are being supported by hatcheries that are at least maintaining populations. Yet, even fish hatcheries may not be enough to stop the tide of decline as they cost billions of dollars to build and maintain and simply aren’t cost-effective in many places. In addition, hatchery salmon behave differently than wild salmon and often don’t grow as large, which in turn has an adverse effect on the species and the environments that depend on them. These fish also compete with wild salmon for food sources and interbreed with them, causing further declines in wild stocks.

“Often the reason behind installing a hatchery is the simple reason that populations are declining, and we install them to stop extinction, maintain a population, or to keep up a treaty with a native tribe that requires a certain number of fish,” Ohms told MeatEater. “While they do help in maintaining fish populations, they are certainly not a long-term solution. Hatcheries cost a lot and hatchery salmon are just different from wild fish. They return at different times than wild populations, generally earlier, and at younger ages, which means that they’re smaller and are possibly not as nutrient-rich as the natural fish.”

Ohms’ work focuses on the evolution of salmon and their life history. She has modeled population dynamics of different species from Alaska and Oregon to Idaho, Washington, and California. Over the years, she has witnessed the decline of wild salmon populations and the worrying effects that it’s having on the environment. She believes that in order to save the fish and reverse the effects, we need to act now.

“It’s like the ship is sinking, and at the moment, we’re almost helpless to stop it,” Ohms told MeatEater. “I think we need as a culture to recognize that we’re sort of at a turning point and that we really need to light a fire under ourselves to take care of the big issues like dams, salmon harvest, and hatcheries if we want to save salmon. I think we need reform, and it needs to happen now. We’re in this window of time where we’re losing genetic diversity, and when your diversity is so low, the fish will get on a trajectory that makes extinction inevitable.”

Ohms and other experts believe that to save the salmon population, the focus needs to be on wild fish, which are better suited to reverse environmental decline as they have evolved over millions of years to do so. With a united front of communication between groups that are removing dams and improving salmon habitat to help wild fish numbers and those advocating for hatcheries and hatchery-raised fish as a subsidy to keep salmon fishing alive, we can perhaps find the ultimate solution.

“I think there are many small situations where hatcheries can be useful,” Ohms said. “When you have a salmon population on the brink, a hatchery can be a way to sustain them until the problem is fixed. However, where we go wrong with hatcheries in 99% of cases is that we use them to prop up a population entirely instead of fixing the problem. If we used hatcheries as a temporary solution until we fix A, B, and C, that would be one thing, but that’s almost never how we use hatcheries, and in their own way, they’re contributing to the problem of losing wild salmon.”

“What we need, I think, is for all these people to decide whether or not salmon are important enough to focus on,” Ohms said. “I mean, we’ve seen the complications that can arise from the Salmon River dams in Idaho. Yet, as a society, we all need to come together to make real changes before we start to see improvements.”

One of the biggest reasons that more emphasis isn’t being put into saving these wild fish populations is that it will take a lot of sacrifice and above all patience from the salmon-loving public to see any results.

“I think a big part of salmon declines is a lack of focus on all the threat factors that are encroaching on salmon,” Marston told MeatEater. “We really need to focus on all the things at once, like closing fisheries and not using hatcheries, and then watching the impacts these things have on wild fish. There’s been a big lack of coordination, especially when all the recovery actions take time. But it’s essential that we give the salmon the time needed for changes to take effect. The average chinook salmon takes four years to return, and it may take 12 years or more for these populations to completely rebound. Yet many Washington state hatchery practices shifted and increased the number of smolt they were stocking because they weren’t seeing immediate effects from fishing closures. It’s going to be really hard to make improvements if we're unable to immediately see the benefits.”

Making the Leap

The fact is that if we want to save wild salmon populations and, subsequently, the environment around them, we must act now and do whatever is necessary to help them along. It may mean helping to improve habitats and advocating for dam removal, and it also may mean that we have to give the fish a chance to recover by putting our salmon rods away for a while.

In the end, such sacrifices will be worth it because we will be helping the salmon of the Pacific Northwest continue to do what they have been doing since the beginning of time—returning from the sea and ensuring that the pulse of the world continues to beat.