Saving the ancient Pacific lamprey

With returning numbers at an all-time low, tribes, agencies, scientists hustle to keep species viable

By Joyce Campbell
    What likes to hang out in the valley’s swimming holes when young, travels to the Pacific Ocean as an adult while sucking the blood of a stronger swimmer, and returns to fresh water rivers to spawn and die?
    Among nature’s most peculiar and ancient creatures, juvenile Pacific lampreys are burrowed into the sand and silt of the Methow and Chewuch rivers, but researchers are worried they may be witnessing the last generation of a species that has survived for 450 million years.
    “The reports aren’t good in terms of numbers,” said John Crandall, local aquatic biologist who has been gathering baseline data in the Methow basin this year for the Wild Fish Conservancy, a non-profit organization dedicated to the recovery and conservation of the Northwest’s wild fish ecosystems. “This year is the lowest recorded count ever, and scientists are not sure why,” he said.
    The number of adults passing through Wells Dam has dropped precipitously in recent years, from 1,400 in 2003, to 35 in 2007. The official count this week is seven, according to the Fish Passage Center at www.fpc.org.
    An effort spearheaded by four tribal organizations has resulted in a collaborative agreement between the Columbia River Inter-Tribal Fish Commission, federal agencies and the Bonneville Power Administration to address the restoration needs of the Pacific lamprey.
    The tribes’ draft restoration plan, released in May 2008, states that the plight of the Pacific lamprey has garnered some attention, but little effective action. It calls for immediate operational and structural modifications to improve dam passage.
    “The biggest problem is getting them into the entrance of the fish ladders,” said Bob Heinith, fishery biologist and hydro program coordinator for the CRITFC. “We’re losing 50 percent as they pass through each dam.” High water velocities, which attract salmon, are a deterrent to the lamprey. Right angles and grated passageways designed for salmon passage don’t work well for lampreys, which rely on sucking their way along smooth surfaces. The Army Corps of Engineers is surveying fishways and experimenting with modifying passageways.
    An important part of restoration work is education, changing the negative public perception of lamprey as an inferior species of very little worth, said Heinith. “They are just as important as salmon in the circle of life.”
    In an emergency measure, the tribes are trapping the fish at lower Columbia River dams and releasing them upstream in tributaries, hoping to keep the population going until further restoration measures are implemented.
    Juvenile lampreys have their own challenges, said Heinith. His agency has asked the Army Corps of Engineers to pull irrigation diversion screens during times when there is no impact to salmon, but where the migrating juveniles get stuck and die.
    Pacific lampreys are eel-like fish that have captured the curiosity of scientists and sustained native people since the last ice age. Sharing similar habitat and habits as salmon, lampreys are spawned in freshwater rivers, where the eggs hatch and float downstream until reaching quiet waters with silt and sand, said Crandall.
    The eyeless ammocoetes – the name of the lampreys in their larval stage – are like aquatic earthworms, filtering the river bottom for nutrients for four to six years before beginning their migration to the Pacific Ocean. Along the way, these evolutionary oddities develop eyes and parasitic abilities, sucking nutrients from various prey fish, including salmon. Their rasp-like teeth hook on to another fish and secrete an anti-coagulant to get a free lunch and a ride at the same time.
    “We don’t know a lot about them, but it appears they don’t kill their host,” said Bianca Streif, aquatic projects coordinator for the U.S. Fish and Wildlife Service. She said when they begin their migration back to fresh water, they stop being parasites and lose up to 30 percent of their weight moving upstream to spawning areas.
    “They are not very good swimmers,” said Streif. “They are burst swimmers, clinging to rocks, staying on a continuous surface to conserve energy.” Passage through the Columbia River dams has proved to be a challenge. “Even low-head dams can pose passage barriers.”
    The fish has other challenges, some natural, some man-made. At every stage of its life cycle, lampreys have been a reliable and nutrient-rich prey for fish, including salmon, birds and sea lions. Habitat disruption, even a temporary de-watering of streambeds for salmon restoration work, can destroy juvenile populations. Toxic substances settling in shallow waterways are deadly to the young ammocoetes. 
   
    Native American tribes from the coast to the interior Columbia and Snake rivers value the Pacific lampreys for subsistence, religious,medicinal, spiritual and cultural purposes. The species’ historic range is from Japan to Alaska and south to Mexico, though today it is not found far south of San Francisco.
    “I like lamprey. It’s a real treat for tribal elders,” said Sarah Thompson, a tribal member and public information officer for CRITFC. She said lampreys have always been available as an important food, incredibly richer in oil and nutrients than salmon. In the spring, in between salmon runs or when salmon runs were low, the lamprey was always there. “They have been there since time immemorial.”
    “Pacific lamprey is easily the most imperiled fish here,” said Crandall. “We don’t really have time to waste. In the last hundred years, this oldest of vertebrates has been driven to the brink of extinction.”
“They are doing something right to still be here after so many things have come and gone, like ice ages, floods and dinosaurs,” said Crandall. “Plants and bacteria are the only other living things that have survived for so long.”

Photo by Joyce Campbell
Photo by Joyce Campbell
Aquatic biologist John Crandall has been researching the ancient Pacific lamprey  in Methow Valley rivers to learn more about the species.