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The lamprey, close to extinction, could bring down NW salmon too

Yakama tribe member, Harry Tomalawash, holding eels ready for roasting by open fire. Credit: Yakama Nation Museum

Plain of color, slimy of skin, devoid of jawline, and nightmarish of mouth, lamprey would handily lose an aquatic beauty pageant. Given their reputation as slimy, blood sucking parasites and invasive pests, they would also place poorly in the personality segment. Even a good result in the talent segment is likely out of their reach, for lamprey are poor swimmers.

Whatever one thinks of the Pacific lamprey’s looks and talents, scientists worry their extinction could mean game over for the recovery of Northwest salmon, which rely on lamprey as a food source. The tribes of the Columbia Basin, to whom the lamprey is an important food source and cultural icon, are one of the eel-like fish’s only advocates. They, along with a handful of marine biologists, are struggling to save the Pacific lamprey from extinction.

According to the U.S. Fish & Wildlife Service, the loss of lamprey is already severe, meaning the species has declined more than 70 percent in range or number. In the Columbia River Basin, the numbers of Pacific lamprey have gone from hundreds of thousands at Celilo Falls (the site of the Bonneville dam), to around 10,000 at ttoday. In many inland streams the species is already functionally extinct. 

The reputation of these aquatic wigglers has been unfairly sullied by the sea lampreys that invaded the Great Lakes in the 1930s. There, with no predators, they eventually threw the food chain out of whack. But unlike its cousins in the Great Lakes, the Pacific lamprey is no interloper. Having co-evolved with the creatures in its current range, it is an integral part of the northwest marine food chain and ecology.

Lamprey spend half of their ten years as larvae, hunkered in silt beds. Some scientists call them the earthworm of the river. At night they emerge to feed, sometimes becoming prey for nocturnal fish. Like salmon, juvenile Pacific lampreys migrate from streams to the ocean, where they spend most of their adult life.

It is at this stage, which lasts for roughly two years, that they feed by latching on to fish and sucking bodily fluids. Though smaller fish may die from these attacks, the larger fish that are more typically targeted usually survive with a circular scar. Lamprey end their adult life, like salmon, by journeying to inland streams to spawn. Rather than jumping up falls on their upstream journey, lamprey swim until they’re tired, then rest by clinging with their mouths to rocks until they regain the strength to continue.

At each stage of their lifecycle, lamprey are food for a number of creatures. Their fatty flesh is high in calories, and along with their poor swimming skills, this makes them a prized and easy catch for fish, birds, and mammals, including seals, sea lions, and people.

While Euro-Americans are largely unaware of lamprey, tribal members of the Columbia Basin have harvested adult lamprey for millennia, roasting and drying them, and extracting their oil to cure earaches and use as a hair conditioner. Lamprey have always been an essential part of the traditional table setting at ceremonial feasts.

“I’m 66 years old, and for all of my life lamprey have been a staple, especially early in my life,” says Tony Washines, an elder of the Yakama Nation. “Later on, as scarcity and degradation of the environment increased due to commerce, agriculture, development, pollution, et cetera, lamprey came to be regarded as a rare delicacy of our people rather than as a staple.”

Like salmon, lampreys were hard hit by the dam construction boom of the ’50s and ’60s. Within a few decades lamprey populations had shrunk dramatically, though they could still be found in some places like Eight Mile Creek, where Washines remembers catching half a burlap sack-full in the mid-1960’s.

“The last time I can recall I went with two of my aunts who wanted to go harvest,” he says. “They said ‘Hey, we’re hungry for eels.’ So I would climb down into the rapids and gather the eels and throw ’em up on the bank, and they’d put ’em in the sack. It was such an integral part of their diet, their lifestyle. They felt a real need to go down and harvest.”

Because they resemble eels, Washines and many other tribal members often refer to them as such.

While salmon, as commercially valuable fish, were provided with fishways for passage at many dams, lampreys are often unable to negotiate fish ladders. According to biologists, only one half of adult lampreys manage to swim past a dam, meaning that if there are 5 dams in their way (as there are on nearly every river in the Northwest), only 3 percent of lamprey will make it through all five.

Though they are probably much more endangered than salmon, they are not officially listed as an endangered species because so little is known about them, and therefore did not get passageways of their own until very recently. Even these are still experimental and installed on only a few Northwest dams.

To make matters worse, dams serve as easy pickings for lamprey predators. The narrowness of fish way entries and exits unnaturally concentrates both fish and lamprey, making it easy for predators of all kinds to snag them. When the river flowed freely, juveniles migrating down stream were helped by current the whole way. Now, the slack water behind dams slow fish down, giving predators — especially birds — more opportunities to catch them. The most vulnerable position for lampreys is at the tailraces of dams, where they are stunned by passage. This is where most predation occurs.

The easy pickings attract ever larger numbers of sea lions, terns, gulls, and sturgeon that add to their decline. This is bad too for other fish, not only because they eat young lamprey, but because these numerous predators turn their attention to other fish — such as salmon — when lampreys are scarce.

After another decade, the catches became even smaller. “Most of the tributaries of Yakima River, which are on the Yakama Reservation, used to have a viable run up until the early 1970s at the latest that we could catch for personal use,” says Washines. “Maybe in the mid to late 70s in the Klickitat River. But it was a scattered harvest. Maybe a couple a night.”

Now, even those scant harvests look good. One of the few places lamprey can still be caught in any numbers is Willamette Falls, because no dams impede their passage to that point. But they nevertheless run a chemical gauntlet, including Portland Harbor — a Superfund site — and culminating with paper mills at the falls themselves. To this day, some tribal members say they can taste chemicals in lamprey harvested there, but until fifteen years ago, it was much worse.

“I have relatives who have gone so far as to state that they were inedible,” says Washines. Since then, the mill operators have cooperated with the tribes, timing the release of chemicals to minimize the impact to the harvest.

“Generally other people thought about lamprey eels the way they think about our brother the coyote, and the way they think about varmints. They call them varmints and trash fish, and they never put very much value on their existence,” he says. “We thought, ‘Well, gee whiz, that means there’ll always be plenty for us.’ But lo and behold, they, like other fish, were very much influenced by the numbers of people and industrial development.”

“Desperate times and desperate measures is basically where we are, with a lot of hard choices based on very insufficient understanding and knowledge,” acknowledges Bob Rose, who coordinates lamprey programs for the Yakama Nation Fisheries.

Lamprey are a subject of the Fish Accords, a partnership between Northwest tribes and federal action agencies to deliver “specific, scientifically valid biological results for the region’s fish.” The funds for the accords are disbursed in conjunction with a ten-year plan and proposals are reviewed by an independent board. Much of the funding devoted to lamprey is devoted to designing and building fish passage at dams — the main focus of the Army Corps of Engineers.

Chris Peery is a fish biologist whose work is funded by the Army Corps of Engineers. His chief concern is passage for lampreys.

“We’ve been able to focus on just one aspect of their life stages at this point, and that’s adult migration,” says Peery. “We think we have a pretty good handle on that and what it would take to fix it. It’s just coming up with engineering design now, in terms of how we develop conditions that allow them to pass dams. All other aspects about juvenile rearing, what’s getting them to go upstream, the genetic structure of the population, what’s going on out in the ocean, those are all just big black boxes.”

A portion of the accord funds will be used to study the population dynamics and movements of lamprey, a task made difficult by the fact that the small size of lampreys make them much more difficult to tag without impacting their behavior and health. Aside from the effects of the tags, the simple act of handling them is problematic: The trauma of the experience affects their behavior, and they can lose some of their protective slime coating, which guards them from fungal infection. Only recently has it become plausible to tag adults, and the tagging of juveniles is still largely experimental.

Still some progress has been made. Early radio telemetry studies of adult lamprey migration in the 90s led to the development of lampramps, and experimentation with river flow rates and times at these structures. Lamprey were attracted to ramps with stronger flow rates, but had trouble getting up such ramps. Now an opening with a high flow rate attracts them, and an adjacent opening with a lower flow allows them to get through more easily. This more closely resembles the sides of cascades that lamprey have evolved to climb.

Though lamprey aren’t as generally athletic as salmon, adults can scale short vertical walls that have a little water running down them. “They coil their bodies up like a spring,” says Peery. “They thrust their bodies forward, and then they detach quickly and then reattach a couple of inches up.”

It is possible to count lamprey passing through lampramps with imaging equipment, including high definition sonar cameras, but they are much more difficult to count than other larger fish. They tend to hug surfaces, are darker in color, and feel safer traveling at night, making video counting tougher. And sometimes an unfortunate lamprey gets washed back down the ramp.

Not only is data difficult to collect, but research progress is slow. Tagging and imaging studies must be repeated for several years to ensure that a change in the number of observed lampreys is caused by a design change and not some other variable. Almost all of these studies are done at the Bonneville Dam, with successful changes being implemented at other dams as funding permits.

Sean Tackley, a fish biologist for the Corps, does much of the work. ”We prioritized our efforts at Bonneville because our goal was to benefit the greatest number of lamprey with the resources we had,” he says. “So we focus low in the system, and where passage efficiency wasn’t as good.”

Already the team has pushed the replacement of screens meant to supply water to the turbines and protect salmon smolts, but which trap migrating lamprey smolt. Though they are expensive, newer screens with smaller openings are being installed slowly. Fish ladders too have been improved to help adult lamprey use them more successfully — without affecting the salmon.

Other improvements benefit all outmigrating species. ”We have these things called Avian Deterrent Arrays,” notes Tackley. “They’re wires that are strung across the tailraces of the dams, which interrupt the flight patterns of the birds. They don’t like to fly around them.”

Biologists are also exploring the idea of hatching and relocating lamprey, although these are controversial measures, given the disappointing results with salmon. (What are these?)

“When we talk about propagation in certain circles,” says Rose, “people immediately want to jump to the salmon world and think about it in terms of ‘you’re going to do it everywhere.’ We’re so far away from that determination that it’s not even part of the cards.”

“We recognize that there may be pitfalls,” continues Rose, “but this is a situation where salmon culture and potential lamprey culture are two different things. If we’re right in our current assessment that the genetics of the lamprey are more homogeneous, then you don’t have those considerations . . . We see this primarily as a research tool rather than as a way of rebuilding populations. However, that doesn’t mean it can’t be used to rebuild populations, we just haven’t figured out how to do that or what it looks like, and where we specifically want to start rebuilding those populations.”

Compared to salmon, lampreys undergo more drastic morphological changes, so it makes most sense to rear them to the larval stage and then release them before the changes occur. Even then, the possibility of maladaptation lurks.

“Once you get the larvae up to, say, three months, how successful are they going to be going off of an artificial feed, like baker’s yeast,” wonders Rose, “and will they have trouble converting to natural feeds, which potentially affects the success of that entire brood class?”

The current difficulty of tracking lampreys make answering such questions problematic. Japanese and Finnish researchers have successfully propagated sea lamprey larvae, but, unable to track them, have no idea how they fared when released. One possible approach is the use of existing pollution abatement ponds at existing hatcheries. These are settling ponds that contain fish waste and uneaten food, but which get a certain amount of water from the river. At one, lamprey larvae washed in through the intake valve, and successfully transformed into smolts.

Another advantage of releasing hatched lamprey at the larval stage is that larvae apparently release pheromones that attract spawning adults. This offers the possibility of jump starting adult migration in upstream areas where they are now extinct. The White Salmon River might be such a spot. With the removal of the Condit Dam, only the Bonneville Dam is in the way of its upper reaches. But there are other obstacles.

“The trouble with the White Salmon is that it’s a pretty steep, swift stream for the most part, with very little rearing habitat,” cautions Rose. “Do we want to be attracting adults into a place where there may not be very many rearing opportunities for the juveniles? We do not know what we want to do in the White Salmon River yet. The two schools of thought are either to just wait and see and learn from nature, or to jump start it.”

No one is sure to what extent Pacific lamprey inhabited the White Salmon basin prior to Condit’s construction in 1913, but biologists are surveying the area for suitable habitat.

“We’ve never thought we would launch directly into propagation as a tool to save the populations,” avers Rose. “Although if you just follow the logic, and you look at how strongly the populations have declined, it quickly leads one to believe that it may be more than likely that we’ll use it as a tool. But that’s a little presumptuous at this point in time.”

Translocation — catching adult lampreys mid-migration and moving them to suitable habitat — is another tool for research and population enhancement. The Umatilla tribe has demonstrated that translocation can be successful in increasing juvenile numbers, but the technique is limited to a small percentage of the lamprey migrating at each dam.

“One thing we haven’t done very well is define where you would use translocation and where you would use artificial propagation, and what’s the difference between the two,” Rose says. “Where we have absolutely no lamprey left in certain areas, my choice would be to put juveniles in some of those areas so that I can see what kind of distribution and dispersion occurs.”

“There is never enough information,” concludes Rose. “We can wait forever for an answer, and tribes right now are not in the mood for continuing to wait and do research. I don’t think the populations are at a place where we can just sit back and do nothing, so we have to do what we can, and do it as conservatively and as prudently as we know how.”

In the meantime, tribes are making do, although not without nostalgia. “We have an ongoing joke that we’re having an eel feast at the longhouse,” continues Washines. “Somebody brings around a plate of hot dogs and says, ‘Oh, we’ve got a plate full of eels today!’ It’s kind of a lament in a backhanded way, because we don’t have the lamprey eel. I miss it on our table. When I was growing up it was almost a foregone conclusion that eel would be part of the setting. Nowadays, it’s a big surprise, a pleasant surprise. You rush to get a piece, get a taste.”

It’s not just the taste that Washines misses, though. The gathering and preparation of lampreys is often a family affair, and a teaching opportunity.

“We have been estranged from the activity of harvesting for so long that children are not acclimated to going down there and taking the eel, and preparing it. Our grandchildren only hear stories of what we did.”

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