Five Pacific lamprey were introduced into the Great Northwest area at the Oregon Zoo in July, and the ancient fish are making themselves right at home, according to zoo officials. The lamprey exhibit will join the salmon, sturgeon, and bald eagle habitats in the cascade stream building.
Their new zoo habitat was paid for in part by the U.S. Fish and Wildlife Service.
The exhibit includes information about their biology, their role in the ecosystem, their cultural importance to the tribes, and tribal and federal efforts to restore their numbers and range. The exhibit is a partnership between the Columbia River Inter-Tribal Fish Commission (CRITFC) and its member tribes, the zoo and the Fish and Wildlife Service.
The five lamprey came to the zoo from the Confederated Tribes of the Umatilla Indian Reservation as part of a tribal-led effort to reduce lamprey decline in the Mid-Columbia region.
Older than dinosaurs and even trees, this 400-million-year-old native species has been an important part of the history and culture of the Pacific Northwest for thousands of years. They are the oldest known fish species in the Columbia River basin.
“They are a very fatty fish, so the Pacific Lamprey have always been an important first food, an important resource of energy,” said Nez Perce tribal member Zachary L. Penney, manager of the CRITFC fishery science department.
Lamprey were often forgotten as fish passage and recovery efforts focused on salmon and steelhead. “Dam passage was designed for salmon. But salmon are strong swimmer, Pacific lamprey need a very different route,” he said.
Lamprey have the ability to hang onto rocks with a suctioning, disc-shaped mouth. Their scientific family name, “Lampetra,” is from the Latin lambere, to suck, and petra, meaning stone. But dam passage through the fish ladders is very difficult for them, especially in high-velocity currents below the dams. The sharp corner of a fish ladder, for example, can break the suction the fish trying to navigate it, and they get washed downstream and out of the ladder system.
As part of restoration efforts over the past 10 years, such corners, and many other impediments to the lamprey, have been modified or removed at Columbia dams, said Laurie Porter, lamprey project leader for CRITFC.
Lamprey passage structures, which resemble a playground slide, have also been developed. “It’s just for the lamprey, so they can suction their way up,” said Porter. A rest stop is also incorporated into the passage design, so the fish can recover from their struggle to ascend the dam.
Scientists continue to collect data on the mysterious fish, using implanted tags and taking DNA samples at various stages of development.
Once Lamprey return upriver and spawn, the eggs hatch tiny larva, only one or two centimeters long, and filter stream sediment for food. On average they spend from 3 to 10 years as larva. They then transition into a juvenile form, called macropthalmia, in which form they migrate to the ocean. Unlike salmon, who return to the same river or stream where they were reared, lamprey have no set destination when they head upstream.
Their time in the ocean is something of a mystery, Porter said, because there isn’t much data available. “There could be some that go out only for a year, others a year or more. Some have gone three years. There’s still a lot we don’t know,” she said.
“They must have adapted to many things in the past, found many ways to survive,” she said of the wide-ranging variables observed.
Pacific lamprey have survived three ice ages and five mass extinctions, but in the past 70 years their numbers have declined, disappearing from their native ranges in the Pacific Northwest. They are now designated as a species of concern by the U.S. Fish & Wildlife Service and by the Oregon and Washington departments of fish and wildlife.
Their current survival in the Mid-Columbia region is improving, not just from improved dam passage but with intensive “translocation” to areas above the dam where they were known to exist in historic times. The five lamprey now at the Oregon Zoo were captured as part of the translocation process.
That program is going very well, Porter said. “We are returning them to habitats where they provided an ecological service, places where they were known to be historically,” she said. “We are seeing success in areas where they were once abundant.”
Generally, however, the numbers are still low, and they are still threatened in many areas.
“They depend on the ocean the way the salmon does, and the salmon are struggling too,” she said. Lamprey number seem to peak and decline, she added. So far this year, returns have been low, but in 2017 they saw one of the highest returns in a decade over Bonneville Dam.
So far this year, both salmon and lamprey passage numbers have been below average.
“We can see that there are peaks, and declines,” she said, and they are trying to piece together the reasons.
“In their new tank these lamprey will be ambassadors helping to educate the general public about this ancient, important and valued Columbia Basin fish,” said CRITFC Executive Director Jaime Pinkham during introduction ceremonies. “They mean a lot to the tribes of the Columbia Basin and we hope that learning about and seeing them, Oregon Zoo visitors will grow to cherish Brother Lamprey, too.”
The planning and development of the exhibit was a year in the making and included tribal representatives, elders, and cultural specialists participating in the entire process.
The lampreys will spend a year in the new 500-gallon exhibit tank. When the fish are ready to spawn, the tribal team will transport them to their original range on tributaries of the upper Columbia River and the Snake River in eastern Oregon to be released, and new sexually immature fish will take their place at the zoo.
For over 10,000 years the people of the Nez Perce, Umatilla, Yakama and Warm Springs tribes, which form the CRITFC, depended on lamprey, salmon, roots and berries. Before the construction of The Dalles Dam in 1957, the river at Celilo Falls was often black with lamprey, commonly called “eels,” according to a CRITFC report. The tribal people used the eel for food and medicine, and many stories and legends surrounding the eel were passed down from generation to generation.
Today, many of the rivers above the dams have no eels, or at best remnant numbers.
Information regarding Pacific lamprey restoration can be found online at www.critfc.org/fish-and-watersheds/columbia-river-fish-species/lamprey.
The Oregon Zoo opens at 9:30 a.m. daily and is located five minutes from downtown Portland, just off Highway 26.