Long, long ago, before the Columbia River Gorge was formed, before the Cascade and Coast Range mountains rose, before the mass extinction of the dinosaurs, at a time before the Pacific Northwest as we know it existed and the western edge of the North American continent terminated somewhere in what is now Idaho, ancestors of the fish species we know today as Pacific Lamprey swam in the warm and salty sea pretty much in the area now occupied by Washington and Oregon.
Then, 90 to 150 million years ago, island archipelagos formed in the ocean and rose in a long, slow-motion collision with the West Coast. Over time an inland sea formed, rivers flowed into it, and the ancestral Columbia carved its initial course. Beginning 40-60 million years ago, chaos roiled the region. The land spilt open, erupting unimaginable volumes of basalt, catastrophic floods carved and re-carved the landscape, pushing, pulling, lifting, and settling the Northwest, and the nascent Columbia formed into the river we know today. Through it all, over hundreds of millions of years, lamprey and their ancestors were here, in the ocean before there was a Pacific Northwest, and in the ocean and river later.
A living link to 150 million years of Northwest history, lamprey indeed are among the most ancient fish of the Columbia River Basin. Lamprey ancestors were in what is now the Missouri River drainage long before that – a fossil found in Montana was dated to 330-360 million years before the present time. The species we know today as Pacific Lamprey in the Columbia River Basin diverged from its ancestors about 4-5 million years ago. Interestingly, modern-day lamprey look a lot like their fossil ancestors, which can be seen as a testament to their amazing resilience to habitat-altering events ranging from volcanism to the rise of mountain ranges and, in modern times, the construction of dams on the Columbia and Snake rivers.
Lamprey, despite their long presence in the region, are poorly understood. Outside of Northwest Indian tribes and fish and wildlife agencies, they are virtually unknown. This may be partly because they don’t attract the kind of public attention salmon and steelhead attract, with their sleek, silver sides and pink flesh. Lamprey are not an appealing fish to look at, particularly if you don’t like snakes. They are long and tube-shaped, have three fins (two dorsal, one caudal, but not opposite each other as with other species) are boneless, dull gray-black to brownish in color, and have a sucking mouth ringed with tiny, sharp teeth.
Lamprey, like salmon and steelhead, once were numerous in the Columbia River Basin, but as salmon and steelhead declined from the impacts of hydropower development, predation, overharvest in the river and ocean, urban development, and pollution, lamprey declined for some of the same reasons. Like salmon and steelhead, lamprey have a deep and enduring connection to tribes, who prize their oily and nutritious, if not necessarily tasty, flesh. For the tribes, lamprey, known by their nickname eels, have cultural, spiritual, ceremonial, and even medicinal importance, and they also have an important ecological value in the streams where they spawn and rear.
As for their taste, it is bitter to the unaccustomed palate and perhaps best described as “acquired,” but their nutritional value is undisputed. Tod Sween, a lamprey biologist for the Nez Perce Tribe, describes them as “swimming sausages” because of their high caloric content. Northwest tribes with access to lamprey learned to preserve the meat which, because it is so oily, would be edible for years if properly dried.
“They are three to four times more oily than salmon,” Sween said. “And, they are easy to catch. They are not the strong swimmers that salmon are, and so basically you go to the places where they are with a basket or a gunny sack and pull them off the rocks.” Harvest time is from May through September.
Pacific Lamprey, the most numerous of the three species found in the Columbia River Basin, and Western River Lamprey are anadromous fish, meaning that they go to the ocean and return to spawn. The third species, Western Brook Lamprey, remains in freshwater for its entire life. Like salmon and steelhead, Pacific Lamprey are born in freshwater, migrate to the ocean, and then return to freshwater to spawn. Unlike salmon, however, they do not always return to the streams where they were born. And there are other differences. In the ocean, Pacific Lamprey are parasitic, attaching themselves to hosts including hake, cod, halibut, sole, and rockfish, but also sharks and whales. They feed on their hosts’ blood and body fluids. After five to six years in this ocean parasitic phase, they return to spawn in the same habitats as salmon and steelhead.
Tribes, along with state and federal agency biologists who work with lamprey, recognize their important ecological and even medicinal values, as well. Like salmon, lamprey provide marine-derived nutrients to the freshwater habitat where they spawn and die. Their oily flesh makes them an important prey species for other fish and animal species. Lamprey also are a bellweather species for water quality, and therefore habitat quality. And lamprey have an interesting medicinal quality. Historically considered an undesirable, parasitic, trash fish outside of tribal cultures, scientists discovered that lampreys secrete an anticoagulant during their parasitic phase, as noted by Dr. Allen Scholz, a fisheries professor at Eastern Washington University, in his four-volume Fishes of Eastern Washington, A Natural History: Lamprey are still regularly collected ... for use as teaching specimens and as a source of medicinal anticoagulants. It is interesting that the anticoagulant produced by this ‘repulsive parasite’ for the purpose of draining blood from its victim has application as an anti-clotting agent in human heart operations. Although we read about the need to protect the biodiversity of tropical rainforests because many unknown organisms may produce useful medicine, the same line of reasoning also applies to organisms that live closer to home in eastern Washington, as the example of the Pacific lamprey illustrates.
Most people know Columbia River lamprey, if they know them at all, from viewing windows in fish ladders at dams, attached by their sucker mouths to the glass with their long, tubular bodies waving like streamers in the swift current. And therein lies a problem for the species.
While fish passage survival for adult salmon and steelhead improved at dams with the installation of fish ladders, these were designed with salmon and steelhead in mind, not anadromous lamprey. Fish ladders for salmon and steelhead are like water-filled staircases, perfect for strong swimmers. But swift current through the ladders makes passage for lamprey difficult. Lamprey, which can swim against a slow current without stopping, aren’t as strong as salmon, and have trouble in the high flow of the ladders. In fast water, lamprey are burst-and-hold swimmers. They use their sucking mouths to hold onto any surface they can attach to, such as the concrete walls of the fish ladders or the glass of the viewing windows, and then release, burst ahead and grab on again. This burst-and-hold swimming method, while efficient, doesn't work well in the fast current of the ladders. And while holding on to a window or wall does not use a lot of energy, if unsuccessful, the lamprey are swept away back down the ladders. Some try repeatedly and succeed, but others try repeatedly and give up.
“This was their biggest obstacle,” Sween said. “As recently as 2009, only 50 percent of migrating lamprey were getting across each dam on the Columbia and Snake rivers, and that year only 12 passed Lower Granite.”
Problems mounted for lamprey over time, and populations declined. In some areas, they became extinct. In the 1950s and 1960s, the number of Pacific Lamprey counted crossing Bonneville Dam each year routinely was between 50,000 and 350,000, but in recent years annual counts of fewer than 150,000 are common (2017 was a big year, with more than 250,000). Dam passage, water pollution, and habitat destruction all played a role in the decline, but so also did a lack of basic understanding about lamprey biology.
Pacific Lamprey once spawned in Columbia River tributaries as far as they could go before their passage was blocked either by natural obstacles like waterfalls or by impassable dams like Grand Coulee and Chief Joseph on the Columbia and the Hells Canyon Complex on the Snake River. In the Columbia, Pacific Lamprey crossed Celilo Falls and made it as far as Kettle Falls. A small number got over that falls and reached British Columbia, where they spawned in the Arrow Lakes above present-day Castlegar, about 800 miles from the ocean, Scholz said.
Pacific Lamprey ascended the Spokane River to Spokane Falls in what is now downtown Spokane, Scholz wrote in Fishes of Eastern Washington. There, the tribes harvested lamprey for their personal use and also to sell at fish markets in the city. The completion of Little Falls Dam in 1911, 29 miles upstream from the confluence of the Spokane and Columbia rivers, extirpated lamprey – and salmon – above that point. In the Snake River, Pacific Lamprey migrated as far as Shoshone Falls, 615 miles from the river’s confluence with the Columbia, but the completion of Hells Canyon Dam in 1967, at Snake River mile 247, blocked their passage.