Because lamprey ammocoetes rivers in the western U.S. In For more information colonize areas and are addition, as Pacific lampreys the following website: relatively immobile in the migrate through reservoirs, stream substrates, they are they may be more susceptible to prone to effects from channel predation. alterations. In addition, the loss Overutilization of adult Pacific of riffle and side channel lampreys: Harvest was habitats may reduce areas for historically more widespread for spawning and for ammocoete lampreys than currently, rearing. though may still present a threat, particularly if concentrated on rivers with low Channelized streams impact numbers. Use of Pacific larval lamprey populations. lampreys for bait has been Credit: discontinued by the states of Oregon and Washington. Ocean conditions (loss of California allows unlimited prey, increase in predators): harvest of lampreys and there Changing ocean conditions is evidence that lampreys are could also be a possible threat regularly collected for bait. to the Pacific lamprey adults. Pacific salmon, Pacific hake, Conservation and walleye pollock have declined in numbers; reductions Opportunities in the availability of these Primary opportunities to host/food species may be protect and restore Pacific affecting adult lamprey survival lamprey populations include: and growth. Provide lamprey passage Protect ammocoete habitat Walleye prey on adult and Restore stream channel juvenile lamprey Credit: Hook Up Guide Service complexity Predation by nonnative fish species: Nonnative fishes such Service biologists place large woody as bass, sunfish, walleye, debris in a stream to restore aquatic striped bass, and catfish, among habitat Credit: USFWS others, have become established over the last century in some
Because lamprey ammocoetes colonize areas and are relatively immobile in the stream substrates, they are prone to effects from channel alterations. In addition, the loss of riffle and side channel habitats may reduce areas for spawning and for ammocoete rearing. Channelized streams impact larval lamprey populations. Credit: Ocean conditions (loss of prey, increase in predators): Changing ocean conditions could also be a possible threat to the Pacific lamprey adults. Pacific salmon, Pacific hake, and walleye pollock have declined in numbers; reductions in the availability of these host/food species may be affecting adult lamprey survival and growth. Walleye prey on adult and juvenile lamprey Credit: Hook Up Guide Service Predation by nonnative fish species: Nonnative fishes such as bass, sunfish, walleye, striped bass, and catfish, among others, have become established over the last century in some rivers in the western U.S. In addition, as Pacific lampreys migrate through reservoirs, they may be more susceptible to predation. Overutilization of adult Pacific lampreys: Harvest was historically more widespread for lampreys than currently, though may still present a threat, particularly if concentrated on rivers with low numbers. Use of Pacific lampreys for bait has been discontinued by the states of Oregon and Washington. California allows unlimited harvest of lampreys and there is evidence that lampreys are regularly collected for bait. Conservation Opportunities Primary opportunities to protect and restore Pacific lamprey populations include: Provide lamprey passage Protect ammocoete habitat Restore stream channel complexity Service biologists place large woody debris in a stream to restore aquatic habitat Credit: USFWS For more information the following website:
PacificLampreyFactSheet_LongVersion%206-22-16.docx