The amazing ancient lamprey

These intriguing and unsettling fish are more important than you might think

Pacific lamprey. Photo: U.S. National Park Service

Written by longtime contributor Valerie Brown, this story was originally published in February 2018 and has remained a favorite of Columbia Insight staff and readers. It’s presented here as part of our Classic Insight series. —Editor

By Valerie Brown, July 14, 2022. Imagine this: You develop from an egg into a larva in fine stream sediment. Over the next three to seven years you live there, eyeless and sexless, eating diatoms and algae.

Then you metamorphose into a male or female fish with a two-lobed dorsal fin, two eyes, no bones and a round mouth with teeth made of keratin (the same thing as fingernails).

Something tells you that you must go down to the sea, where you affix your mouth to the side of a bigger fish and suck its fluids out for your own benefit.

After a few years doing this, you get the call to return home, so you swim upstream, leapfrogging your way through rapids by glomming your mouth onto rock above rock above rock, until you reach your original stream. Or something quite like it.

You never eat again. You spawn and die. Congratulations! You are a lamprey.

The lamprey is clearly not an example of “charismatic megafauna,” like bears and wolves, but it’s nevertheless a vital member of the Pacific Northwest ecosystem and an icon for Native Americans, who prize the fish for food, medicine and ceremony.

Sadly, Pacific lamprey and their cousins, river lamprey, have all but disappeared from Northwest rivers and streams. Like the Pacific salmon that migrate up the very same rivers to spawn in fall and winter, they’ve felt the devastating effects of habitat loss, dams, chemical pollution and dredging.

What’s their problem?

Compared with salmon, lamprey have 20% more protein and eight times their fat content.

This makes them popular with predators but also results in accumulations of heavy metals like mercury and persistent fat-loving chemicals such as certain pesticides and PCBs.

Lamprey larvae are also heavily exposed to pollutants during their long residence in stream sediments.

Remediating dredge spoils on the Middle Fork of the John Day River. Photo: Sam Beebe/Ecotrust/CC 

Dredging has been a problem for lamprey because dredges scrape up the stream bed and deposit it chaotically, mobilizing mercury deposits as well as throwing lamprey larvae—called ammocoetes—out of the water and destroying their habitats.

Dams, however, appear to be the biggest thing lampreys can’t adapt to. Lamprey don’t do well with the accommodations aimed at salmon because they’re weaker swimmers, and need round surfaces, rather than right angles, in order to lock their lips on something to climb.

About half of them simply give up after repeated tries at fish ladders.

Many ammocoetes also find themselves marooned in farmers’ fields and ditches because the meshes inserted into irrigation outflows, designed for salmon, are too big to keep lamprey out.

Recovery

There are some 39 species of lamprey around the world, about half of which are parasitic. In the Northwest, Pacific and river lampreys are parasitic, while brook lampreys are not. The first two are also anadromous, meaning they migrate between freshwater and saltwater.

In the Northwest, lamprey have historically been regarded by European Americans as trash fish that damage sport fish, and in the past, they were sometimes poisoned or harvested for fish meal.

According to Sara Thompson of the Columbia Intertribal Fish Commission, the only place in Oregon where tribal members can currently harvest lamprey in any quantity is at Willamette Falls near Oregon City—historically one of the largest sources of lamprey in the Columbia Basin, although tribal memory recalls vastly more at Celilo Falls on the Columbia before construction of The Dalles Dam.

But in the Columbia River Basin there is now a concerted effort to restore the lamprey for both cultural and ecological reasons.

There is some good news regarding this effort. In 2008, the Army Corps of Engineers embarked on a $50 million search for better lamprey passage designs, especially at the Bonneville Dam, a 200-foot wall of concrete that creates one of the most daunting obstacles for lamprey along the entire Columbia River.

Likewise, three lamprey summits since 2004 led to a commitment by the U.S. Fish & Wildlife Service to work toward lamprey recovery with the tribes, state and local agencies, and other stakeholders. In 2012, these groups signed a conservation agreement to restore Pacific lamprey to their historical range and to preserve the tribes’ cultural uses of lamprey.

Lamprey pre-date dinosaurs. They’ve survived for 300 to 400 million years. Photo: U.S. Fish & Wildlife Service

The Yakama Nation’s goal “is to bring back the lamprey in abundance, so they’re there in the stream and in sustainable numbers that allows the tribal members to harvest them,” says Ralph Lampman, lamprey research biologist for Yakama Nation Fisheries.

To that end, the tribe has established a lamprey hatchery to study the fish’s life history, genetics, and survival challenges. The Nez Perce Tribe has also established a hatchery in an attempt to return lamprey to the Snake River Basin, which has been almost completely inaccessible to the fish since dam construction.

The Confederated Tribes of the Umatilla Indian Reservation have begun an ambitious program of research, translocation and hatchery propagation of lamprey (along with habitat restoration) on the Umatilla, Walla Walla and Grande Ronde Rivers.

The Confederated Tribes of Warm Springs are also working on lamprey recovery in the Deschutes River and other waterways that originate on their land. In 2016, they completed rehabilitation of the heavily dredged Oxbow area on the Middle Fork of the John Day River.

In the Gorge, the removal in 2010 of the Powerdale Dam in Oregon’s Hood River and the Condit Dam in Washington’s White Salmon River has allowed Pacific lamprey to return to these rivers all on their own.

Acquired taste

Those who study these strange, unattractive fish—often called eels—tend to become admirers.

Margaret Docker, who is one of the world’s leading lamprey experts and a biology professor at the University of Manitoba, began her life’s work in graduate school studying the Great Lakes’ invasive Atlantic sea lampreys.

“My research was focused on how to kill them, but within about six months, I had started to develop a grudging respect,” Docker says. “No matter what we tried to do to control them they were one step ahead of us. Within a number of years I was an apologist.”

She is fascinated by the lamprey’s sexual differentiation and behavior, especially because relatively little of their lives is actually lived as one sex or the other.

Lampreys’ very survival suggests that they’re more malleable, perhaps even wilier, than we give them credit for.

“The key to them having survived for 300 to 400 million years [is] that instead of becoming specialists, they’re generalists: freshwater resident/anadromous; parasitic/not parasitic; this stream/that stream,” Docker says. “Lamprey have only rudimentary vertebrae, but in terms of brain development and a lot of other things they have characteristic hallmarks of vertebrate evolution, a development of brain and sense organs that you don’t see in invertebrates.”

Lampreys’ intriguing evolutionary pedigree has inspired other scientists to use them as lab animals to examine their development and compare it with “higher” vertebrates. Neuroscientists are studying how lampreys use the neurotransmitter serotonin, as well as other brain chemicals they share in common with humans.

This is currently a bit difficult, given that lamprey spend three to seven years as larvae and their life cycles are far more complex than those of experimental subjects such as mice.

To many people, the thought of eating a lamprey is, well, icky. But these fish have been prized around the world for millennia.

Native Americans view the lamprey as a First Food, a creature that gave up its life to humans in exchange for human environmental stewardship.

Northwest tribes cook lamprey on a stick over a fire, smoke them and use the oil for medicines, including dried lamprey tail as a pain reliever for teething babies, Lampman says.

Lampman developed his taste for lamprey in Japan, where they’re eaten as sashimi and in stir fries.

“They can be chewy,” he says, but slow cooking takes care of that. “In the Northwest, lamprey are often grilled and eaten on a hot dog bun.”

In Europe, the lamprey has remained popular, especially in Portugal, where one sea lamprey can fetch upward of $60. Medieval England even incorporated lamprey into royal politics, resulting in the City of Gloucester owing the sovereign a lamprey pie every year, and at least one British family coat of arms stylized lampreys.

Wayback machine

Because lampreys are primitive cousins of creatures like our own deep ancestors, evolutionary biologists and molecular geneticists are very interested in them.

These fish have survived at least two major mass extinctions and dozens of minor ones without significant alterations in their anatomy or lifestyle.

Classified as vertebrates, lamprey departed ways with our own lineage when other fish started developing jaws, bones and fins.

Molecular clock analysis suggests this happened “on the order of 500 million years ago—but it may go much deeper,” says Michael Coates, a research associate in geology at the Field Museum of Natural History in Chicago.

Coates, who is hunting for the common ancestor of lampreys and other bony fish, was on a 2006 research team that discovered a lovely impression of a lamprey about 1.6 inches long in 360-million-year-old South African rocks.

“What amazed me was to find a lamprey that was so close to modern lampreys anatomically,” Coates says.

R-E-S-P-E-C-T

The lampreys’ most important feature is their role in ecosystems, a crucial role that has been ignored for far too long.

Lamprey enhance the surroundings at both ends of their life cycle— cleaning up stream bed sediment, recycling nutrients, serving as food for other fish as larvae and adults and transporting minerals from the sea up into the tributary systems of the Columbia drainage when they die.

They also form a protective buffer for salmon because they’re easier for predators to catch. So no matter how gross they might seem, there are many reasons to honor the lamprey and encourage their recovery.

“It’s so reassuring to see such interest in lampreys these days,” says Docker. “For the last 20 years of my career I had people telling me, ‘Margaret, you can’t make a career out of lampreys.’ They’ve finally come into their own.”

Valerie Brown specializes in science and environment writing, particularly environmental health and climate change, including the health effects of chemical and radiation exposures, carbon sequestration and climate change’s effects on forests and oceans.