Month: January 2023

The land and ocean may seem like separate entities—one solid and secure and the other a watery depth—but the connection between the two is multifold and profound.

Salmonids provide one such connection. Salmon are considered anadromous, meaning they travel between their freshwater birthplace, to the ocean, and back. Upon returning home, they spawn the next generation of salmon before they inevitably die—completing their lifecycle.

By feeding in the ocean for anywhere from two to seven years, depending on the species, salmon bring marine nutrients to the terrestrial environment. Streamside vegetation gets anywhere from just under 25% to 70% of its nitrogen from salmon. Studies have shown in at least some instances, trees grow faster near salmon nesting grounds.

Salmon are also culturally important fish—providing food for people of the Pacific Northwest for thousands of years.  And, in modern times, salmon fisheries have grown in scale and significance. As a result, salmon have also received a lot of attention from the scientific world.

Yet, despite the vast amount of research done on salmon, there is still a lot that is unknown about salmonid species, especially when it comes to their time spent in the ocean.

This is where Laurie Weitkamp comes in. A marine ecologist with NOAA, Laurie has been studying salmon her entire career—working to understand their complex behaviors and lifestyles to better inform fisheries management. In recent years, she has joined multi-week expeditions in the Pacific Ocean in pursuit of a better understanding of their marine life.

I met with Laurie at a local trail in Newport with the hopes of gaining keener insight into her research. We also planned to hunt for chanterelle mushrooms along the way.

Fish and fungi—now there is nothing more Pacific Northwest than that!

Conserving Fish

Laurie and I began our hike on a gravel road shaded by Sitka spruce and western hemlock—a quintessential coastal forest. It had rained a lot the night before, but this morning was mild and comfortable as we followed the road downhill.

As we walked, I asked Laurie for a quick bio.

“I have been a research fisheries biologist for the Northwest Fisheries Science Center—one of, I think, six regional Centers around the country, and part of NOAA fisheries,” Laurie described. “I have been doing this for 30 years now.”

“Congratulations,” I exclaimed. “That is an accomplishment.”

So, what has Laurie been up to these last 30  years?

It turns out, quite a lot!

Laurie is a salmon biologist with a strong focus on salmon conservation. One of her main projects over the years has been to provide 5-year status updates on West Coast Coho—a  threatened salmon species under the Endangered Species Act. In fact, she was the lead author of the West Coast Coho Status Review which led to its original listing back in 1994-95.

“We just finished our status review update with data from 2019,” said Laurie.

You couldn’t tell just by looking at her, but Laurie is a rockstar salmon biologist.

Hatchery Fish Problem

As Laurie and I continued following the gravel path, we got to talking about the hatchery fish problem. 

Hatchery fish are ubiquitous. Bred to improve salmon populations, but they have taken a toll on wild population fitness.

In fact, according to Laurie, stray hatchery fish was a major factor in the original ESA listing for Coho. 

“Hatchery fish are essential to fisheries,” Laurie explained, but when we don’t keep tabs on them, that creates a problem. “You can’t tell what is going on [to wild populations],” in that case.

“There is a lot of evidence that when you get all of these hatchery fish it depressed the fitness of wild populations,” Laurie went on.

There are studies that have shown this. Breed a wild fish with a hatchery fish and they have fewer offspring. Though it is unclear why.

For these reasons, Laurie has differentiated between hatchery fish and wild fish populations in her conservation and policy work.

Wild populations “are the building blocks,” she explained. “They are critical to the continuation of the species,” deemed “evolutionarily significant.”

Stay Wild

Therefore, to keep wild populations wild, a few things needed to change.

Fortunately, a lot has changed since the original ESA listings.

“One of the things the state of Oregon did is close down all the Oregon Coast hatcheries. We went from eight million to 300,000 hatchery fish, so they effectively shut down.”

The other thing that changed is Oregon started marking hatchery fish by removing their adipose fin before releasing them.

“It is all automated,” said Laurie. “They go into a slot, measure how long the fish is… and clip…thousands are done per hour.”

The results of these changes have been positive.

For one, the “wild population increased in productivity by 25%,” said Laurie.

Second, these “evolutionarily significant” wild fish are protected from fishermen. “

You aren’t allowed to keep anything that has an adipose fin,” Laurie explained. “That is huge! And in response to ESA listing.”

Change is a Coming

The ESA listing of salmon species has resulted in other changes as well.

For example, land policy has changed. Laurie mentioned the Oregon Forest Practices Act update—requiring larger buffer zones on streams to protect fish.

Despite these changes, salmon populations are still struggling. Marine heatwaves have knocked down populations. And no ESA-listed salmon population has been delisted.

For some, this may be seen as a failure, but not for Laurie.

“It is impressive,” she stated. “None have been taken off, but none have gone extinct.”

And there have been some wins too. Laurie told me that about 1 million sockeye returned to the Columbia this year to spawn. Perhaps the largest sockeye run since the Columbia River dams went in back in the 1930s.

Not bad, considering what salmon are up against.

Segue into Research

As we continued past more second-growth Sitka spruce on moss and fern-covered slopes, we saw someone coming from the opposite direction with a basket of chanterelles—the popular mushroom that we planned to hunt for that day.

Laurie playfully asked if had left some behind. He offered a quick “no” and a chuckle. Laurie laughed too, undeterred. Her positivity was infectious.

Then Laurie gracefully segued into her research work.

“I am trying to understand what goes on in the Ocean,” Laurie explained.

You may recall, salmon are anadromous fish. They are born in freshwater, but then spend a lot of their lives in the Ocean—some salmon species up to 7 or 8 years—before returning to their natal stream to spawn. 

“A vast majority of the little guys don’t make it back,” said Laurie. “Some 95-99% of salmon that enter the Ocean do not survive…. That is kinda the odds.”

Laurie was quick to clarify that these odds are not unusual or necessarily related to human impacts. It is their survival strategy.

“The average female lays 3000 eggs,” said Laurie, “two need to survive.”

So, the question is Why? Why do so few salmon make it back?

This is the question Laurie has been aiming to answer.

Bottom-up

According to Laurie, there are two main approaches to consider when it comes to salmon loss—either top-down or bottom-up. The bottom-up approach considers how populations are controlled by the organisms at the trophic level below them, i.e., their food.

In the case of salmon, it requires looking at prey availability for the species. Depending on the species, this might be krill, jellyfish, or smaller forage fish.

So, what does Laurie’s research suggest regarding this bottom-up approach?

“If the water is cold and there is a lot of prey available,” said Laurie, “[salmon] do well.”

In other words, both cold temperatures, which help with upwelling and make the Ocean more productive, and food availability work together to regulate salmon.

According to Laurie, there is a lot of evidence that points to bottom-up being “really important.”

It is also relatively easy to study—just catch a few salmon and look in their stomachs—but it is only half the equation.

Top-down

A top-down approach suggests the opposite—that populations are controlled by organisms at the trophic level above them, i.e. their predators.

Salmon predators are numerous and become even more numerous as the oceans warm.

“When the water is really warm,” explained Laurie, “you get warm water predators that come up [from the south],” like hake or pacific whiting.

“Hake are incredibly abundant fish,” said Laurie.

Normally summer guests, with ocean warming, hake are extending their stay in the Pacific Northwest for a longer amount of time.

I Hake you

At this point, you may be thinking:

So, just how much salmon are hake consuming?

Turns out the answer is complicated.

Laurie told me about a study she was involved in that looked at how much mackerels and hake predated on salmon as they came out of the Columbia. They sampled thousands of these predators’ stomachs for about ten years and found less than a dozen salmon in their stomach contents.

“Salmon are pretty rare,” Laurie explained. “There are a hundred times more other anchovies out there that they [mackerels and hake] are feeding on.”

To add to the difficulty, the stomach contents of any fish only reflect the last 24 hours of feeding. Eat a salmon on Tuesday, by same time Wednesday, any sign that the feeding took place is gone.

Take Terns

Seabirds, like terns and cormorants, are another predator of salmon that scientists are watching.

In this case, some researchers are using tagged salmon to monitor their predation.

“They [the researchers] put pit tags in individual fish,” Laurie explained. As the birds eat the fish, they also consume their pit tags.

“Then they go over the tern and cormorant colonies after they left in winter or fall… They run over the thing and detect the salmon that were eaten and pooped out in the bird colonies.”

Counting pit tags, “those are the easy situations,” Laurie admitted.

In short, “Predation is really hard to study.”

Chanterelles

We had been hiking for about 45 minutes when we passed one of Laurie’s chanterelle spots. The ground was covered in moss and growing thick with salal and evergreen huckleberry. Tall Sitka spruce trees with their cylindrical trunks made up the overstory.

“It has not been a very good chanterelle year,” Laurie remarked as she searched the edge of the woods.

However, soon enough Laurie found one of the golden beauties.

“Chanterelles look like that,” Laurie held up her find, “with an irregular shape… and they have branched gills that are primitive gills.”

In contrast, false chanterelles have an uneven coloring compared to chanterelles—“dark in the middle and light on edges.” False chanterelles also have true gills that fork near the cap margins. 

There were a lot of false chanterelles.

Nutrient Connection

As we searched the area for more chanterelles, I asked Laurie if there was any connection between salmon and chanterelles.

Her answer was a brisk “no,” but just as quickly, she reconsidered. Laurie had a quick wit about her.

“Well habitats that are good for chanterelles are also good for salmon,” she noted.

It turns out I was in the right habitat at that moment—soon I had a couple of good-sized chanterelles in my possession.

“Found two!”

Speaking of seconds, I suggested to Laurie another connection between salmon and chanterelles—nutrients.

Salmonids have a unique role in nutrient cycling—they carry marine nutrients from the ocean to inland areas. From here, fungi help decompose the dead salmon bodies, or the waste generated from an organism that consumed their bodies, releasing those marine nutrients to fertilize the coastal forest. 

“There is all kinds of work that shows that trees grow faster along salmon runs,” Laurie observed.

She also mentioned the role lamprey, another anadromous species, plays in fertilizing the forest.

“It is really cool because they bring up nutrients as well,” said Laurie. “They can go up vertical surfaces…” she explained, “and they can get into places salmon cannot, and fertilize streams that salmon cannot.”

At this point we had exhausted our chanterelle patch, so we headed back to the road.

Not long after, we passed by a disturbed area where I noticed a stand of skinny alder trees. Dark green alder leaves lay scattered on the ground—another good fertilizer. Fish fungi, and trees—all helping keep the forest green.

High Seas

We were about halfway through our hike when we turned onto another road.  The plan was to travel it for a while before taking a bike path back to complete a loop. This was our migratory route.  But what of our fish?

As mentioned earlier, salmon move from freshwater to the ocean and back again—sometimes spending years fattening up in a marine environment. But, last I checked, the ocean is huge.

Which begs the question—where do salmon go once, they reach the deep blue?

“They head north,” Laurie asserted. Or at least most do.

Sockeye, chum, and coho all head up to Cape Flattery then onto Canada and Alaska, according to Laurie. They follow the continental shelf for a season, their paths tracked as they pass various outposts along the way, before dropping off the shelf and entering the “deep sea.”

Though, they may as well be dropping off the face of the Earth because, at that point, they could be anywhere.

“We don’t see them again until they come home,” explained Laurie. “It is like a huge washing machine out there.”

It is Laurie’s work to visit the washing machine, but more on that later.

Keeping Track

As we crunched along the gravel road, I asked Laurie to tell me more about how scientists were tracking fish.

Even before salmon enter the deep sea, they are difficult to track. As Laurie put it—“we get mixed results.”

“The number of fish you need to tag to get robust results has been really limited,” she explained.

At the same time, knowing the populations and how they are doing is important work. Salmon are valuable and cross [international ]borders.

Laurie told me about the Fraser Sockeye, for example—a large and extremely valuable fish. So valuable that a treaty was established between several tribes of western Washington, the U.S. government, Canada, plus U.S. states and Canadian provinces to ensure the fishery is sustainable.

So, tracking matters because salmon matter. They matter enough for international treaties to be enacted.

Fish are tracked in several ways. When it comes to the Fraser Sockeye, acoustic tags are used. These send out unique radio signals, allowing you to identify individual fish. The drawback is you need receivers close enough to hear the signal.

“The continental shelf in some areas is 30 miles wide. That is a lot of real estate,” Laurie proclaimed.

Another option is to use satellite tags. A benefit of satellite tags is that you can see where the fish is, as well as other data like temperature, pressure, and depth from anywhere. The drawbacks are that you must get the tag back to download all the data and, because of the size of the tags, only older adult fish can carry them.

Laurie told me about a study using satellite tags where researchers were getting a slightly elevated constant temperature reading from their chinook for a long period of time.  

“What they think is that salmon sharks were consuming these Chinook,” Laurie laughed. The constant temperature was recorded from inside the digestive tracks of the salmon sharks. 

Eaten

A break in the trees brightened the path as we reached a high point in the trail. Though the sky was overcast with clouds, the light from the sun cast a dim reminder of its existence through the gray shroud.

Laurie shifted the conversation back to her work on the high seas. This is where things get even more murky.

Laurie started by talking about her work detecting salmon predators on the high seas.

“It is really hard to figure out,” Laurie stated. “It is hard to tell who is doing the predating and when…. Are they [predators] only getting the small fish [salmon] or the sick fish [salmon]?”

In 2019, 2020, and 2022, Laurie and her team did an extensive study of salmon predators using eDNA and didn’t find many.

eDNA is a newer technology, where water samples are gathered and sent into a lab to be tested for the DNA of species of interest, like salmon predators. Because organisms are constantly sloughing off DNA, this is a good way to gauge the presence of a species even when it is not caught in nets.

“We found a couple of predatory salmon sharks and a couple of fish, lancetfish, and daggertooths, that eat strips of salmon…,” said Laurie.

“They aren’t here. We are not catching them in the nets or detecting their DNA.”

Starving

So, what is going on?

Another “arm-chair hypothesis” is that the salmon are starving during the winter. Salmon that don’t get fat over the summer don’t survive onces winter arrives. This would be especially important for small fish because they can’t store much energy.  Laurie and her team tested this hypothesis.

“We get out there and ocean age 1 fish are going great, but 2s and 3s are not looking great,” said Laurie. “They are really skinny.”

They took blood samples of the fish to test for Insulin Growth Factor (IGF)—a chemical that signals healthy growth in fish. As expected, fish that were in the ocean for 1 year, have high levels of IGF.

But those in year 2 or 3 had either really high levels or really low levels.  They also had green gallbladders—a sign of starvation.

“What’s going on?” asked Laurie.

It is still unclear.

“You answer one question,” Laurie smiled, “and you generate five.”

Do We Stay or Do We Go

Not all salmon spend a lot of time in the ocean, however,“it depends on the species”—a statement I heard a lot from Laurie.

Chum and sockeye are really the only ones with an extended high seas stay.

“What we think happens is they spend winters in the Gulf of Alaska and move into the Bering Sea in the summer until they are ready to come home.”

“Others are only a year,” said Laurie, like Coho.

Then there is fall chinook…

“Fall chinook stay on the continental shelf,” said Laurie. They travel back and forth along the coast for years before returning.

Every species has its own way.

“What is really cool is the whole idea of these chum salmon ages 2 and 3 being skinny. All different stocks are together in the Bering Sea.”

Bang for your Buck

Laurie and I reached our turn-off onto a mountain biker trail. Steep and a little slippery, we both carefully navigated our way down the path.

Laurie pointed out a patch of slippery jack mushrooms as we passed by.

“People do eat them,” she noted, but their slimy appearance didn’t appeal to either of us, so we trod on. 

“Anyway, there is all kinds of really cool stuff we are finding being out there [at sea],” Laurie proclaimed. She had a knack for transitions. “It is also really expensive… 32 days at $30,000 per day.”

With that sort of price tag, a lot of work happens before these expeditions to plan and prepare. Using freshwater data and developing hypotheses are vital steps to take beforehand. 

“The idea is we are trying to get the most bang for our buck…” Laurie explained.  “Using the information [from other sources] so when we are not out there, we can still understand what is going on.”

Food for Thought

While we were talking, suddenly Laurie made bee-lined it off the trail—a massive burnt orange-colored lobster mushroom was growing just off the trail.

“Wow!” Laurie exclaimed, “I don’t think I have ever seen this large a lobster. These are one of my favorites!”

Unfortunately, it was a bit too old and soft to take home and eat, but we took a picture of it to commemorate the find.

“Still cool…” Laurie said as she put it down on the mossy ground.

My mind turned to food, I asked—“What are they eating?”

“Depends on the species,” said Laurie.

Hmmm, that sounds oddly familiar.

“Sockeye and Pink salmon eat low in the food chain—a lot of zooplankton.”

Sockeye’s red flesh is a result of carotenoids from zooplankton being incorporated into their tissue.

“So, the chum are famous for eating a lot of gelatinous stuff,” Laurie continued, “like jellyfish and evolutionary dead ends, like tunicates, they tend to like.”

“Coho, Chinook, and steelhead start with zooplankton and graduate to larval and juvenile fish and squid.”

It’s Getting Hot in Here

Soon we were off the biker trail and on another gravel road. We passed by some salmonberry shrubs—“any connection there?” I asked, referring to salmon.

“Nope, they just look like their eggs,” said Laurie. That’s what I thought, but worth an ask.

We passed by some more possible chanterelle spots, but only picked one more immature mushroom.

We climbed up onto a small, forested hill next to a creek to check for chanterelles. The hill was dense, shaded, and cool.

While we foraged around, I asked Laurie what she thought the underlying issues were for salmon success. Does it come down to getting enough food?

Though she agreed that food was a big part of it, she was quick to point out that it was probably not just one thing, but rather a host of interacting factors.

High ocean temperatures, for example, impacts many of the other factors associated with salmon success, including food availability.

“The ocean absorbs 90% of the excess heat that we have been putting into the atmosphere,” Laurie stated. “Climate warming is really ocean warming. Even below 5000 meters, it is getting warmer.”

Ocean warming is a factor that cannot be ignored.

Beaver Believers

A murky creek slogged along a the bottom of the forest.

“That is great coho salmon,” said Laurie. “They love side channels in the winter.”

Coho salmon are Laurie’s specialty, having studied them more than any other species. Though a coastal species, they spend a lot less time in the ocean than other species—only a year, though some males may only spend six months—and more time in freshwater.

I asked Laurie if she could tell me anything else about coho that makes them unique. Her response—beaver.

“Coho benefits the most from returning beavers,” said Laurie. “They really do well with beaver ponds.”

Beaver are what are called ecosystem engineers—they transform bottomlands, creating ponds pools, and wetlands.  As Laurie put it, “They create “killer coho habitat.” 

Laurie told me about early coho research she did in 1987 in Alaska. They would follow the coastal streams up, stopping at each beaver pond to catch count, measure, and weigh coho. Even five beaver dams up, they were still catching coho.

“Coho were flourishing in these beaver ponds,” said Laurie. “They know how to get through the dams.”

Young steelhead and spring chinook love riffles and high mountain streams. Not coho. They like low-gradient streams with connected floodplains.

And of course, they love beavers. 

Own up

However, good coho habitat is not easy to come by, as many of the places coho and beaver enjoys, humans like as well.

As Laurie and I popped back onto the gravel road to continue our journey back to our cars, I asked Laurie if there was anything people could do to help coho and other salmon species.

“The biggest thing is just taking ownership,” said Laurie. Understanding that everyone can be either part of the problem or part of the solution is an important first step.

Next, get involved. Laurie suggested participating in local watershed counsels and estuary conservation groups.  A lot of times these groups will have opportunities to give back, including planting native vegetation.

Beyond this, “there are easy things you can do,” Laurie exclaimed—“don’t pour oil down the storm drain… think about what you are going to have in your yard…,” she suggested for example. 

Reducing pollution and creating natural filters that slow water, are both helpful to fish. High flows can scour out salmon nests, called redds, and carry silt that smothers salmon eggs.

Pollutants can sometimes accumulate in salmon in high concentrations, reducing their ability to fight off disease and sometimes killing them outright before they can spawn. Laurie mentioned a tire preservative that has increased pre-spawning mortality in salmon.

“Even in high seas, they [salmon] have detectible levels [of pollution],” said Laurie.

Sea Legs

Laurie and I continued to discuss the challenges facing salmon as we hiked the gravel road, a better option for salmon than pavement.

We passed by a newt that was exceptionally skinny. Could it be feeling the same strains as salmon feel with winter coming on? I wonder.

 I could see the gate ahead of us when I asked Laurie about what it was like to work on the high seas.

“Some days, I think, I can’t believe I am getting paid to be out here,” she smiled, “Other days, I think, they are not paying me enough.”

Laurie has been going to sea for the last 30 years with several weeks on the boat each time. That is a lot of hours clocked on a moving vessel. The seasickness and tight quarters get to you at times, but then there are moments of pure joy and wonder.

Sauté  

Soon we are back to our vehicles. We stood and chatted for a few more minutes about lamprey and the vastness of the ocean before we decided to part ways.

As I began to walk off, Laurie gave me one more piece of advice—“Cook them in a dry pan,” said Laurie, referring to the chanterelles, “medium heat.”

And with that, I migrated home. Fish, fungi, forest, and me—we are all connected.

Laurie Weitkamp is a Research Fisheries Biologist with the Northwest Fisheries Science Center since 1992.