Lampreys are much overlooked but crucial species to the health of the Upper Klamath Lake ecosystem

Following the removal of four dams on the Klamath River, salmon have been getting the most attention as they migrate upstream to newly available habitats for the first time in over a century. Another fish species is not getting as much focus, but it is still an essential part of the Klamath Basin’s ecosystem – the Pacific lamprey.

Klamath Tribes Ambodat Anadromous Fish Specialist Jordan Ortega is one fish biologist monitoring Pacific lamprey, which, like salmon, are anadromous. They spend their early life stages of development in freshwater as filter feeders, migrate to the ocean to feed as vertebrate parasites, and then return to spawn in tributaries along the Klamath River.

Ortega said that the lamprey is a primitive vertebrate during an interview with Klamath Tribes News. They are jawless and branched off early in the family tree of vertebrates and fishes. Some adult-feeding lamprey arescavengers, others predators, and some parasitic, sucking blood and body fluids. They are found on every continent except Africa and Antarctica. “In the Klamath Basin, Pacific lamprey are native to this watershed,” he said. “But within the Upper Klamath Basin, we also have a variety of other lamprey species, and one of the more awesome little facts about the Upper Klamath Basin is that it actually hosts the most species of lamprey out of any other watershed on the planet.”

The non-anadromous Upper Klamath Lake Lamprey is an undescribed parasitic species largely restricted upstream of Upper Klamath Lake, feeding on the blood and tissue of koptu and c’waam suckers, redband trout, Blue Chub, and Tui Chub. There’s also a species called the Klamath River lamprey found in Upper Klamath Lake. “This species is distributed throughout the Klamath Watershed from near the mouth of the Klamath upstream to tributaries of Upper Klamath Lake,” Ortega explained. “It is a non-anadromous species, but they are voracious. “They are highly parasitic; they pepper salmonids and anything else they can get their mouth on,” Ortega said. “So, when we first observed salmon entering Spencer Creek in the upper basin after dam removal, we noticed a lot of lamprey wounds on these fish, and the likely candidate is the Klamath River lamprey downriver.”

He said there are diverse run times of Pacific lamprey in the Klamath Basin, a unique aspect of the species that is not generally found throughout its range. “We have early maturing and early entering lamprey,” he said, “and we also have late maturing, late migrating lamprey, and so that’s kind of similar to the summer versus winter steelhead life history, or to the fall and spring Chinook life history, in which adults will enter the river early on with undeveloped gonads, or they’re not sexually mature yet, and then they’ll sexually mature in the river, whereas the other life history will be sexually mature when they enter the river, and they’re basically ready to spawn.”

Though not a first food of the Native tribes of the Upper Klamath Basin, they were a food source, but not a primary source like suckers and trout. “I’d say what’s most common is, or what’s most commonly understood, is that Pacific lamprey was (and still are) the principal lamprey that Indigenous peoples used as a food source, but other lampreys were used as well, and actually, a more recent harvest of these happened at the Chiloquin Dam,” Ortega said. “I’ve heard from various tribal members that they remember as kids going down to the dam and seeing all these eels, and then they would collect and harvest them.” He added that Pacific lamprey is a traditional and vital food source for the Yurok Tribe in California, and it is harvested each year in the lower Klamath River.”

He cited another Lamprey, not a Pacific lamprey, but an Atlantic sea lamprey, which is also a popular dish in many European countries. “I think it’s more of just an unusual type of fish that people find visually unpleasant, and that’s why many people talk about them not being very tasteful,” he said. Ortega tried lamprey when a tribal member smoked one and offered it to him. “I was pleasantly surprised to find it very tasty, a combination of salmon and sardine, with a similar texture to salmon,” he said.

Pacific lamprey-like Chinook salmon in the Klamath Basin were impacted by the four dams on the Klamath River, which blocked their migration routes to tributaries in the Upper Klamath Basin. With the dams removed, Ortega suspects Pacific lamprey will migrate upstream to explore newly available habitats. However, two obstacles impede their migration to the Upper Klamath Basin – the Link River and Keno dams. “They were not built for lamprey passage,” Ortega said. “Lamprey do not like 90-degree angles. And so, a lot of times, fish ladders will have these long troughs that have these kinds of cement boxes in them, and they’re very angular. They’re squared off. Salmon can jump over one box to the next, through the trough, but the lamprey has a harder time navigating those angled surfaces.”

But there may be an easy fix to the problem. “I was just informed on this the other day from a lamprey expert in California who’s done a lot of work on lamprey passage,” he said, “but apparently, you can basically stick a glorified PVC into the bays, and if there are any passage issues, they can navigate that PVC pipe and get from bay to bay. Lamprey passage is something that people are concerned about at Keno and Link River dams, and there are currently efforts to assess the structures, understand what needs to be done, and implement what needs to be done, such that lamprey passages is good.”

Ortega said there are four or five species of lamprey (depending on who you’re speaking with) in the Upper Klamath Basin, and they generally have healthy populations. However, as the Pacific lamprey begins entering the waterways in the Basin, they could have a tough time finding a niche in habitats upstream of Upper Klamath Lake with all the already well-established lampreys.

“It’s similar to redband and steelhead trout, two species vying for niche habitats in the Upper Klamath Basin,” Ortega said. “And, so, we might see something similar with Pacific Lamprey where there’s just a lot of niche competition, and they may struggle to gain a foothold up here, but downriver, in the Spencer Creek area, you have a much lower diversity of lampreys, so there’s more niche availability for them.”

He’s hopeful the Pacific lamprey will make it to Spencer Creek, given the lack of niche competition and the fact that there are no dams in the way. “But when you overlay Keno and Link River Dams and all the species of lamprey in Upper Klamath Lake, I think it just suggests that who knows what will happen,” he said.

Like suckers, Ortega said lampreys are tough fish and have survived and thrived in Upper Klamath Lake, despite poor water quality. He said lamprey are plentiful in the Upper Klamath Basin waterways, likely millions in number, and they play an essential role in the ecosystem’s health. “They actually have two critical ecosystem services, which is why we need to protect them,” he said. “One of which is the filter-feeding larval stage. And, so, they’re filtering out detritus, harmful chemicals, and things out of the water columns – similar to mussels that also filter and clean the water column.”

“The second service,” he continued, “is that it provides upstream spawning migrations and brings marine or Upper Klamath Lake-derived nutrients up into these really nutrient-poor parts of the landscape because, like salmon lamprey die after they spawn, and that’s going to fuel the base of the food chain, which is going to drive better growth for all sorts of different things, from bugs to fish to birds to everything, trees, riparian zones.”

Ortega said the lamprey in Upper Klamath Lake could be viewed as a kind of “keystone species” because of the ecological benefits derived from its activities, and for this reason, it must be acknowledged as an important species to protect and research. “I think you could argue that there’s an ecologically specific definition for a keystone species that has numbers and thresholds,” he said, “but I think everything matters, right? At some scale or some level, you could probably argue that negative ecosystem responses would happen by removing a species like lamprey.”