SPECIES: Scientific [common] Entosphenus tridentatus [Pacific lamprey] Forest: Salmon-Challis National Forest Forest Reviewer: Bart L. Gamett Date of Review: March 16, 2018 Forest concurrence (or Yes recommendation if new) for inclusion of species on list of potential SCC: (Enter Yes or No)
FOREST REVIEW RESULTS:
1. The Forest concurs or recommends the species for inclusion on the list of potential SCC: Yes_X_ No___
2. Rationale for not concurring is based on (check all that apply): Species is not native to the plan area ______Species is not known to occur in the plan area ______Species persistence in the plan area is not of substantial concern ______
FOREST REVIEW INFORMATION:
1. Is the Species Native to the Plan Area? Yes_X__ No___
If no, provide explanation and stop assessment.
2. Is the Species Known to Occur within the Planning Area? Yes_X__ No___
If no, stop assessment.
Table 1. Selected sampling sites from sampling efforts in 2006 and 2007 where Pacific Lamprey were detected on the Salmon-Challis National Forest.
Stream Location Year Observed Source Information Middle Fork Salmon River 0.9 km below Loon 2006 IDFG (2011) Creek (at RKM 45) Middle Fork Salmon River upper Grouse Camp 2006 IDFG (2011)
Middle Fork Salmon River 30 m above mouth of 2006 IDFG (2011) Camas Creek Middle Fork Salmon River sandy beach above bend 2006 IDFG (2011) by Aparejo Point Rapids Middle Fork Salmon River Mormon Ranch (RKM 2006 IDFG (2011) 30.0) Middle Fork Salmon River 1.4 km above 2006 IDFG (2011) Foundation Creek Middle Fork Salmon River 0.4 km above White 2006 IDFG (2011) Creek Middle Fork Salmon River 0.2 km above Camas 2006 IDFG (2011) Creek Middle Fork Salmon River below Jackass Rapids 2006 IDFG (2011)
Middle Fork Salmon River above mouth of 2006 IDFG (2011) Woolard Creek Middle Fork Salmon River 0.7 km above Papoose 2006 IDFG (2011) Creek Middle Fork Salmon River 0.5 km above 2006 IDFG (2011) confluence of Salmon R. Middle Fork Salmon River 0.3 km below Stoddard 2006 IDFG (2011) Creek Middle Fork Salmon River 0.67 km below Nolan 2006 IDFG (2011) Creek Salmon River 100 m below Corn Creek 2006 IDFG (2011)
Salmon River 0.66 km above Middle 2006 IDFG (2011) Fork Salmon River 0.37 km above Owl 2006 IDFG (2011) Creek Salmon River 3.3 km above Panther 2006 IDFG (2011) Creek Salmon River 350 m above Shoup 2006 IDFG (2011)
Salmon River at Indian Creek at 2006 IDFG (2011) Indianola Salmon River 0.66 km below North 2006 IDFG (2011) Fork Salmon River 0.8 km below mouth of 2006 IDFG (2011) N.F. Salmon R. Middle Fork Salmon River Mouth of Bernard Creek 2006 Gamett and Bartel (2011)
Middle Fork Salmon River Mouth of Camas Creek 2007 Gamett and Bartel (2011)
a. Are all Species Occurrences Only Accidental or Transient?
Yes___ No_X__
If yes, document source for determination and stop assessment.
b. For species with known occurrences on the Forest since 1990, based on the number of observations and/or year of last observation, can the species be presumed to be established or becoming established in the plan area?
Yes_X__ No___
If no, provide explanation and stop assessment
c. For species with known occurrences on the Forest predating 1990, does the weight of evidence suggest the species still occurs in the plan area?
Yes___ No___
Provide explanation for determination
N/A—occurrences have been documented since 1990.
If determination is no, stop assessment
d. Map 1, Pacific lamprey (Entosphenus tridentatus) range in Idaho (IDFG 2018)
IDFG (Idaho Department of Fish and Game). 2018. Pacific lamprey (Entosphenus tridentatus). Internet website: https://idfg.idaho.gov/species/taxa/17473. Accessed on January 8, 2018.
e. Map 2, Known occurrences of Pacific lamprey (Entosphenus tridentatus) on the Salmon-Challis National Forest.
3. Is There Substantial Concern for the Species’ Capability to persist Over the Long-term in the Plan Area Based on Best Available Scientific Information?
Table 2. Status summary based on existing conservation assessments
Entity Status/Rank (include definition if Other) NatureServe G4— Apparently Secure (Uncommon but not rare; some cause for long-term concern due to declines or other factors) Global Rank NatureServe S1—Critically Imperiled (At very high risk of extinction due to extreme rarity (often 5 or fewer populations), very steep declines, State Rank or other factors) State List IDFG—Endangered (A native species in danger of extinction throughout all or a significant portion of its Idaho range) Status SGCN Tier 1— Highest priority species with the most critical conservation needs (i.e., an early-warning list of taxa that may be heading toward extirpation) USDA Forest R1—No status Service R4—No status
USDI FWS No status Pacific lamprey was petitioned for listing in 2003, but USFWS found the species not warranted for listing in 2004 Other BLM sensitive species Type 2—Rangewide/Globally Imperiled Species (These are species that are experiencing significant declines throughout their range with a high likelihood of being listed in the foreseeable future due to their rarity and/or significant endangerment factors)
Table 3. Status summary based on best available scientific information.
Species (Scientific and Common Name): Entosphenus tridentatus (Pacific lamprey)
Criteria Rank Rationale Literature Citations 1 A1 Pacific lamprey are native to the Salmon River basin and occur on the Gamett, B. L. and J. A. Bartel. 2011. Distribution on Salmon-Challis National Forest in the Salmon River and Middle Fork The Status of Fishes on the Middle Salmon-Challis Salmon River (on the Middle Fork and North Fork Ranger Districts). Fork Ranger District, Salmon-Challis National Forest Within the Middle Fork Ranger District, Pacific lamprey appear to have a National Forest (2002-2008). South limited distribution, confined to the Middle Fork Salmon River below Zone Fish Program, Salmon-Challis Foundation Creek (Gamett and Bartel 2011). They are not known to National Forest. March 15, 2011.
Species (Scientific and Common Name): Entosphenus tridentatus (Pacific lamprey)
Criteria Rank Rationale Literature Citations occur in other locations of the Forest within the Salmon River basin nor on National Forest lands in the Big Lost River, Little Lost River, Birch USFS (United States Department of Creek, or Wood River basins (USFS 2017a). Agriculture, Forest Service). 2017a. An Assessment of Aquatic Species Because Pacific lamprey only occur in portions of two rivers on the on the Salmon–Challis National Forest, habitat for Pacific lamprey on the Forest is limited (Rank A1). Forest in Support of Forest Plan Confidence is medium because lamprey ammocoetes (i.e., larvae), which Revision. Draft 12-05-2017. live within stream substrates, may not be detected by routine electrofishing and snorkeling efforts (Gamett and Bartel 2011).
Confidence in Rank: High, Medium, or Low 2 C Pacific lamprey are found in rivers around the North Pacific Ocean from IDFG (Idaho Department of Fish Distribution in Hokkaido, Japan to Alaska and south to southern Baja California. and Game). 2005. Pacific lamprey surrounding Landlocked populations occur in lakes or reservoirs in British Columbia, (Lampetra tridentata). Internet geographic area Oregon, California, and possibly elsewhere (NatureServe 2018). website: https://idfg.idaho.gov/ifwis/cwcs/p In North America, Pacific lamprey were historically widespread along the df/Pacific%20Lamprey.pdf. west coast of the US from Baja California to the Aleutian Islands, but Accessed on January 8, 2018. populations have declined in abundance and distribution throughout California, Oregon, Washington, and Idaho (USFWS 2011; NatureServe IDFG (Idaho Department of Fish 2018). In Idaho, the species originally occurred in all drainages of the and Game). 2017b. State Wildlife Snake River below Shoshone Falls, except the Palouse River. It is now Action Plan. Boise, Idaho. restricted to the Clearwater and Salmon River drainages and tributaries of the Snake River below Hells Canyon Dam (IDFG 2005, 2017b). NatureServe. 2018. NatureServe Explorer: An online encyclopedia of Despite large-scale declines in their range, Pacific lamprey are still widely life [web application]. Version 7.1. distributed outside the Forest. NatureServe, Arlington, Virginia. Internet website: Confidence in Rank: High, Medium, or Low http://explorer.natureserve.org.
Species (Scientific and Common Name): Entosphenus tridentatus (Pacific lamprey)
Criteria Rank Rationale Literature Citations Accessed on January 8, 2018.
USFWS (United States Fish and Wildlife Service). 2011. Pacific Lamprey (Entosphenus tridentatus) Assessment and Template for Conservation Measures. Region 1, USFWS. Portland, OR. 3 B Pacific lamprey are mainly anadromous, that is, they migrate up rivers Bartel, J. A., B. L. Gamett, M. A. Dispersal from the sea to spawn, although land-locked populations migrate only Haroldsen, and J. Vacirca. 2007. Capability between lakes and spawning streams. Newly metamorphosed individuals Stream Diversions on the migrate from parent streams to the Pacific Ocean, where they spend Middle Fork Ranger District, several years (typically 1–3) before returning to rivers to spawn Salmon-Challis National Forest. (NatureServe 2018). Migrations, such as those made by Snake River November 27, 2007. populations, may be up to several hundred kilometers long (McIlraith et al. 2015). Cochnauer T., and C. Claire. 2009. Evaluate status of Pacific lamprey in Artificial barriers strongly impact the species’ migratory success; juvenile the Clearwater and Salmon River lamprey originating in the Snake River, Salmon, and Clearwater River drainages, Idaho. Draft basins need to pass through eight mainstem hydroelectric dams to Conservation Plan. Boise (ID): Idaho migrate from headwater spawning areas to the Pacific Ocean and again Department of Fish and Game. as returning adults (Cochnauer and Claire 2009). Lamprey have difficulty passing through many of these dams, which create slow-moving Gamett, B. 2018. Fish Biologist on backwaters that prolong migration and are fitted with ladders designed the Salmon-Challis National Forest. for salmonids that do not facilitate lamprey passage (Cochnauer and Personal communication regarding Claire 2009; USFWS 2011). Pacific lamprey with Lindsay Chipman, Biologist at EMPSi. Dams are rare directly on the Forest, and though there are 19 active and January 18, 2018. 11 abandoned diversions in the Middle Fork Ranger District, impacts to fish movement are thought to be slight as most diversions are small and McIlraith, B. J., C. C. Caudill, B. P.
Species (Scientific and Common Name): Entosphenus tridentatus (Pacific lamprey)
Criteria Rank Rationale Literature Citations the amount of water removed is low (Bartel et al. 2007; B. Gamett, Kennedy, C. A. Peery, and M. L. personal communication). In addition, many diversions on the Salmon Keefer. 2015. Seasonal Migration River drainage have screening to prevent entrainment and allow passage Behaviors and Distribution of Adult of downstream salmonid migrants, and Pacific lamprey may have Pacific Lampreys in Unimpounded benefited to varying degrees by these modifications, though this has not Reaches of the Snake River Basin. been documented (IDFG 2011). North American Journal of Fisheries Management, 35:1, 123-134. Even though Pacific lamprey are adapted for long-distance travel, and impacts from dams and diversions on the Forest are thought to be low, hydroelectric dams in the lower Columbia and Snake rivers may impede Forest populations from successfully migrating to complete required life history phases (Rank B).
Confidence in Rank: High, Medium, or Low 4 A The Pacific lamprey was once abundant in Idaho waters and juveniles Hyatt, M., C. W. Claire, and T. G. Abundance on the were commonly seen in Idaho streams in the 1960s (IDFG 2005). The Cochnauer. 2007. Evaluate status of Salmon-Challis species’ current range extent in Idaho is 43,900 km2 (~16,900 mi2), and Pacific Lamprey in the Clearwater National Forest the state’s population size is estimated as only 50–250 fish (IDFG 2017b). River Drainage, Idaho. Idaho However, Pacific lamprey are difficult to enumerate because they tend to Department of Fish and Game, move at night when fish counts at dams are not conducted; they are able Bonneville Power Administration to bypass the count window; and they can climb vertically on smooth wet Annual Report. Portland, OR. surfaces, allowing them to pass upstream undetected (IDFG 2013). IDFG (Idaho Department of Fish Although lamprey have been historically documented in the Salmon River and Game). 2011. The Status of drainage upstream to Alturas Lake, the Middle Fork Salmon River is Pacific Lamprey (Entosphenus probably the only tributary in which Pacific lamprey are currently present tridentatus) in Idaho. July 2011. (IDFG 2011). Sampling by IDFG in 2005–2006 documented Pacific Boise, ID. lamprey in the Salmon River upstream to the North Fork Salmon River at river kilometer (rkm) 381.4 (Hyatt et al. 2007; IDFG 2011). The presence
Species (Scientific and Common Name): Entosphenus tridentatus (Pacific lamprey)
Criteria Rank Rationale Literature Citations of young age classes in these waters indicates that successful spawning is occurring on an annual basis or every several years below the North Fork Salmon River (IDFG 2011). On the Middle Fork Salmon River watershed, the current distribution of Pacific lamprey is restricted to the mainstem from the mouth upstream to rkm 78.7, just upstream of Loon Creek (IDFG 2011). There has been an incremental increase in the length of minimum length groups from 2005 to 2006; a shift to older age groups would indicate a lack of spawning, but this must be confirmed by future sampling (IDFG 2011). During Forest surveys from 2002–2008, Pacific lamprey were collected at two sites on the Forest: the Middle Fork Salmon River near the mouth of Bernard Creek and on the Middle Fork Salmon River at mouth of Camas Creek (Gamett and Bartel 2011). Pacific lamprey were absent at the majority of sampled sites.
Surveys indicated Pacific lamprey abundance ranging from 0 to 20 fish/m2 in the mainstem Salmon River (below little Salmon River) and from 83 to 617 fish/m2 in the Middle Fork Salmon River (Hyatt 2007). Fewer than 200 fish were suspected to have spawned in Salmon River drainages annually from 1995 to 2006 (Hyatt 2007).
The above data indicate that abundance of Pacific lamprey on the Forest is far lower than historical levels (Rank A). Confidence is medium due to difficulty in detecting Pacific lamprey and because surveys were not specific to the Forest (IDFG 2011).
Confidence in Rank: High, Medium, or Low 5 A In Idaho, populations have shown a short-term decline of 10%–30% and a Population Trend long-term decline of over 90% (IDFG 2017b). Declining passage of adult on the Salmon- lamprey over lower Columbia and Snake River dams indicates a Challis National downward trend in abundance from 1962–2006 (Hyatt 2007), which
Species (Scientific and Common Name): Entosphenus tridentatus (Pacific lamprey)
Criteria Rank Rationale Literature Citations Forest translates to a decrease in the number of fish travelling to and from Snake River drainages, including Forest habitat. Accordingly, Pacific lamprey have substantially declined in both distribution and abundance on the Forest (USFS 2017a).
Pacific lamprey are likely no longer present in most 3rd, 4th, and 5th order streams in the Salmon River drainage upstream of the Middle Fork Salmon River. In 2005 and 2006, no ammocoetes were found in the Lemhi River, Pahsimeroi River, East Fork Salmon River, Yankee Fork of the Salmon River, or the upper mainstem Salmon River, suggesting these systems no longer support Pacific lamprey populations (Hyatt 2007).
Pacific lamprey have experienced large declines in populations and distribution throughout Idaho and on the Forest (Rank A). Confidence is medium due to difficulty in detecting Pacific lamprey and because surveys were not specific to the Forest (IDFG 2011).
Confidence in Rank: High, Medium, or Low 6 B Pacific lamprey occupy freshwater benthic habitats as larvae, freshwater Claire, C. W., T. G. Cochnauer, and Habitat Trend on streams and rivers as downstream migrating juveniles, the ocean as G. W. LaBar. 2007. Pacific lamprey the Salmon-Challis parasitic adults, and freshwater again during upstream migration and ammocoete habitat utilization in National Forest spawning. Ammocoetes inhabit shallow backwaters and eddies along Red River Idaho. American Fisheries edges of streams in mud, silt, and sand. Ammocoete density in the Red Society Symposium, 53:151–161. River of the South Fork Clearwater River drainage decreased with increased velocity and coarse substrate, but increased with fine and USFS (United States Department of medium substrates and riparian shade (Claire et al. 2007). Adults spawn Agriculture, Forest Service). 2017b. in runs and riffles in rock-, sand-, or gravel-bottomed clear streams and in Salmon Challis National Forest Data small, shallow depressions at the heads of riffles, typically at depths of Assessment, Riparian Ecosystems 30–150 cm (NatureServe 2018). Section (Draft a).
Species (Scientific and Common Name): Entosphenus tridentatus (Pacific lamprey)
Criteria Rank Rationale Literature Citations Available data suggests that the distribution of Pacific lamprey on the Salmon-Challis National Forest is limited to the Middle Fork Salmon River downstream of Indian Creek and the Salmon River. Much of this habitat falls within the 10G (Steep Canyonlands in Granite) or 10Q (Steep Canyonlands in Quartzite) land type associations (LTAs) on the Forest (USFS 2017b). Rapid fluctuations in reservoir and stream water levels from irrigation diversions, power hydropeaking, and instream channel activities can impact Pacific lamprey by stranding ammocoetes in substrate and isolating them from flowing water; dessicating nests; or impeding adult lamprey migration (USFWS 2011). Indicators of the condition of water fluctuations in surface water systems show that LTAs associated with Pacific lamprey habitat are mainly trending towards the natural range of variation (NRV), despite large deviations elsewhere on the Forest (USFS 2017b). Although hydroelectric impoundments on major Salmon River drainage streams have been limited to two sites, which currently do not strongly impact fish habitats (IDFG 2011), major dams downstream of the Forest can interfere with the lamprey’s ability to successfully migrate (see Criteria 3 and 7).
Water quality is important for spawning and larval development. Water temperatures ≥22°C can cause mortality or deformation of eggs and early stage ammocoetes. In addition, ammocoetes, which are relatively immobile in stream substrates, are susceptible to water pollutants (USFWS 2011). Fine sediment values as measured by median substrate size are within historic parameters in the LTAs used by Pacific lamprey (USFS 2017b). Based on indicators for water quality in surface water systems, water quality in the majority of lamprey habitat is within the NRV. Likewise, the composition and condition of riparian ecosystems is considered within the NRV in LTAs occupied by lamprey (USFS 2017b).
Species (Scientific and Common Name): Entosphenus tridentatus (Pacific lamprey)
Criteria Rank Rationale Literature Citations All of the Middle Fork Salmon River downstream of Indian Creek is within the Frank Church-River of No Return Wilderness. Despite minor anthropogenic impacts associated with recreation and activities in the watershed upstream of this reach (see Criterion 7), this area exhibits high viability due to the abundance of large connected habitats and roadless lands with high ecological integrity (IDFG 2017b). Portions of the Salmon River on the Salmon-Challis National Forest are within or bordered by the Frank Church-River of No Return Wilderness, which provides protection from anthropogenic impacts. Roads, recreation, and anthropogenic activities in the watershed upstream of this reach have all impacted the river, riparian area, stream flows, and/or water quality. However, the impact of these activities is not expected to increase significantly in the future (see Criterion 7).
In summary, key ecosystem characteristics in LTAs occupied by Pacific lamprey are largely within or trending towards the NRV. Because the majority of Pacific lamprey habitat lies within or near the Frank Church- River of No Return Wilderness, anthropogenic impacts to habitat are expected to be minor now and into the future (Rank B).
Confidence in Rank: High, Medium, or Low 7 A Restricted passage due to hydroelectric dams in the Columbia and Snake Behrens, P.N., R.E. Keane, D.L. Vulnerability of Rivers is the primary factor affecting the persistence of Pacific lamprey in Peterson, and J.J. Ho. 2018. Habitats on the Idaho (IDFG 2017b). Many adult fish passages (e.g., ladders) are designed Chapter 6: effects of climatic Salmon-Challis to allow passage of other fish species (e.g., salmonids) but prevent variability and change on forest National Forest passage of lamprey and in some cases cause mortality (USFWS 2011). vegetation. In Halofsky, J.E., D.L. Although dams are rare on the Forest and impacts to lamprey from Peterson, J.J. Ho, N.L. Little, L.A. diversions are thought to be small, barriers off the Forest still pose a Joyce, editors. 2018. Climate large threat to migrating fish (see Criterion 3). change vulnerability and
Species (Scientific and Common Name): Entosphenus tridentatus (Pacific lamprey)
Criteria Rank Rationale Literature Citations adaptation in the Intermountain Roads and recreation can degrade habitat conditions for lamprey by Region. Gen. Tech. Rep. RMRS-GTR- reducing water quality, increasing sedimentation, and decreasing 374. Fort Collins, CO: US streambank integrity. Some habitat impacts have probably occurred on Department of Agriculture, Forest the mainstem Salmon River due to the high density of roads and trails on Service, Rocky Mountain Research the North Fork Ranger District, including a Forest road that runs along the Station. Salmon River (Google Earth 2018; USFS 2016). However, all Pacific lamprey habitat on the Middle Fork Salmon River is within the Frank Google Earth. 2018. Salmon–Challis Church-River of No Return Wilderness, so roads are not a threat. Minor National Forest, Idaho. Internet habitat impacts may occur due to the trail network and increased human website: presence (USFS 2017c). Recreational boating, which is a popular https://www.google.com/earth/. recreation on the Main Salmon and Middle Fork Salmon Rivers on the Accessed on January 4, 2018. Forest, also increases human presence in lamprey habitat and can Halofsky, J.E., D.L. Peterson, J.J. Ho, decrease water quality and overall habitat conditions, but effects are N.L. Little, L.A. Joyce, editors. 2018. probably minor and not expected to increase in the future (IDFG 2016b). Climate change vulnerability and adaptation in the Intermountain Unrestricted livestock grazing can also degrade lamprey habitat by Region. Gen. Tech. Rep. RMRS-GTR- causing erosion, decreased streambank integrity, and reduced water 374. Fort Collins, CO: US quality. However, relative to other ranger districts, the area of active Department of Agriculture, Forest grazing allotments on the Middle Fork and North Fork Ranger Districts is Service, Rocky Mountain Research low (Google Earth 2018; USFS 2016, 2017b). In 2012, 78% of 107 Station. monitored pastures in riparian areas of the Forest met percent the forage utilization standard, indicating that conditions are improving Joyce, L.A. and M. Talbert. 2018. (USFS 2016b). Therefore, grazing is not expected to be a major threat to Chapter 3: Historical and projected this species on the Forest. climate. In Halofsky, J.E., D.L. Peterson, J.J. Ho, N.L. Little, L.A. Given that Pacific lamprey spend several years in marine environments, Joyce, editors. 2018. Climate oceanic conditions that affect lamprey, their prey species, or pelagic or change vulnerability and substrate habitats may alter population demographics (Orlov et al. 2008). adaptation in the Intermountain Additional research, evaluation and monitoring are needed to determine Region. Gen. Tech. Rep. RMRS-GTR-
Species (Scientific and Common Name): Entosphenus tridentatus (Pacific lamprey)
Criteria Rank Rationale Literature Citations how actions are reflected in the population. 374. Fort Collins, CO: US Department of Agriculture, Forest Changes in climate could also impact this species. Changes in climate are Service, Rocky Mountain Research expected to increase air temperatures and decrease snow to rain ratios Station. which will likely result in a smaller snowpacks, changes in stream flow patterns, and higher stream temperatures (IAP 2016). These changes IAP (Intermountain Adaption could negatively impact this species. Partnership). 2016. Intermountain Adaption Partnership: Climate To project the future climate and impacts to resources in the Vulnerability Assessment Intermountain Region including the Salmon-Challis, the Intermountain Summaries (Draft). Adaptation Partnership (IAP) used Representative Concentration IDFG (Idaho Department of Fish Pathway [RCP] 4.5 and 8.5, which capture a moderate and high future and Game). 2013. Fisheries warming, respectively (Halofsky et al. 2018). Although pathways Management Plan 2013–2018; A predicting lower warming exist, the 4.5 and 8.5 pathways were chosen by Comprehensive Guide to Managing the IAP because they are, in comparison, well studied providing a large Idaho’s Fisheries Resources. set of projections that enhance our understanding of the possible range Internet website: in future climate. Thus, this represents best available science for our https://idfg.idaho.gov/old- Forest with regard to a warming climate. web/docs/fish/planFisheries.pdf. Accessed on January 4, 2018. Although uncertainty exists about the magnitude and rate of changes in climate (For a discussion of this see Behrens et al. 2018), warming Orlov, A. M., V. F. Savinyh, and D. temperatures are the most certain consequence of increased CO2 in the V. Pelenev. 2008. Features of the atmosphere. By 2100, median minimum and maximum temperature in spatial distribution and size the Middle Rockies subregion, which includes the Salmon-Challis, is structure of the Pacific lamprey projected to rise about 5-6˚F under the moderate warming scenario and Lampetra tridentata in the North about 10˚F under the high warming scenario. Regardless of scenario, the Pacific. Russian Journal of Marine greatest departure from historical seasonal minimum temperatures Biology, 34(5): 276–287. occurs in the summer. Annual precipitation projections are highly variable with no discernible trend under moderate warming and a slight USFS. 2016a. GIS Database increasing trend with high warming (Joyce and Talbert 2018). Information. Last updated March
Species (Scientific and Common Name): Entosphenus tridentatus (Pacific lamprey)
Criteria Rank Rationale Literature Citations 30, 2016. In summary, threats from anthropogenic activities directly on the Forest are low. However, barriers off the Forest that interfere with migration USFS (United States Forest Service) and changes in climate are major threats to Pacific lamprey and could Salmon-Challis National Forest. cause effects outside the NRV (Rank A). 2016. Forest plan monitoring and evaluation report: Salmon-Challis Confidence in Rank: High, Medium, or Low National Forest: Salmon and Challis Forest plans FY 2012, 2013, 2014, and 2015.
USFS (United States Department of Agriculture, Forest Service). 2017c. Salmon–Challis National Forest Draft Assessment Report. October 2017.
8 A Pacific lamprey populations were split at one time into Entosphenus Close, D. A., M. Fitzpatrick, and H. Life History and tridentatus (Columbia River and north) and E. ciliatus (Klamath River and Li. 2002. The ecological and cultural Demographics south). However, this division is no longer recognized, and the two importance of a species at risk of names are considered synonyms (NatureServe 2018). In 2003, this extinction, Pacific Lamprey. species was petitioned for listing under the Endangered Species Act, but Fisheries 27:19-25. found not warranted for listing in 2004 (USFWS 2004). The Pacific Lamprey Conservation Initiative was established in 2012 to promote USFWS (United States Fish and conservation measures for the species in Alaska, Washington, Oregon, Wildlife Service). 2004. Endangered Idaho, and California (UFWS 2012). and Threatened Wildlife and Plants; 90-Day Finding on a The Pacific lamprey’s life cycle can be divided into four stages: Petition To List Three Species of spawning/adult, rearing/ammocoetes, metamorphosis/macropthalmia, Lampreys as Threatened or ocean phase/macropthalmia to adult. Adult lampreys are parasitic and Endangered. feed on a wide variety of ocean fishes, including Pacific salmon, flatfish,
Species (Scientific and Common Name): Entosphenus tridentatus (Pacific lamprey)
Criteria Rank Rationale Literature Citations rockfish, and pollock. They have been caught in depths ranging from 300 USFWS (United States Fish and to 2,600 ft (90 to 800 m), and as far as 62 miles off the coast (100 km) in Wildlife Service). 2012. ocean haul nets (Close et al. 2002). Conservation Agreement for Pacific Lamprey (Entosphenus tridentatus) After spending 1 to 3 years in the ocean, Pacific lampreys return to in the States of Alaska, Washington, freshwater between February and June, where they remain for Oregon, Idaho, and California. approximately 1 year before spawning. Spawning typically occurs in the Portland, OR. spring; reproductive rates are potentially high but are variable, with females producing between 30,000 and 230,000 eggs, which are Wallace, R. L. and D. W. Zaroban. deposited in nests or depressions (Wallace and Zaroban 2018). Embryos 2013. Native Fishes of Idaho. hatch after about 19 days at 59°F (15°C). Once ammocoetes reach about American Fisheries Society. 6 in (15 cm), they begin metamorphosis into macropthalmia or juveniles Bethesda, Maryland. and migrate downstream to the ocean between late fall and spring where they mature into adults (USFWS 2004).
High incidence of metacercarial infections of Pacific lamprey by the digenetic trematode Nanophyetus salmincola have been reported for ammocoetes in the mainstem Salmon River (Hyatt 2007). Mortality due to this pathogen is variable and related to the rate of accumulation, fish size, species and stock susceptibility, infection site, and absolute number of metacercaria. Future research is needed to determine whether this parasite negatively affects ammocoetes in the Salmon River, and if so, to what degree and how (Hyatt 2007).
Harvest of Pacific Lamprey may present a threat in rivers with low population numbers but is prohibited in Idaho as the species is listed as endangered by the Idaho Department of Fish and Game (IDFG 2013). Predation by native and non-native fish, marine mammals, and birds may pose a threat to lamprey abundance, particularly in areas with low population levels or altered habitat. Pacific lamprey may be more
Species (Scientific and Common Name): Entosphenus tridentatus (Pacific lamprey)
Criteria Rank Rationale Literature Citations susceptible to predation while migrating through reservoirs and associated dams. Non-native predators such as bass, sunfish, walleye, striped bass, and catfish have become established in some rivers in the western U.S. over the last century (USFWS 2011).
The species’ low population size (Criterion 4) and numerous threats that may decrease survival rates (Criterion 7) suggest a low ability to recover from disturbance (Rank A). Confidence is medium because reproductive rates are variable.
Confidence in Rank: High, Medium, or Low Summary and recommendations: Date: 1/14/2017 Current conservation assessments indicate high statewide concern for the Pacify lamprey—IDFG classified the Pacific lamprey as endangered due to low and declining populations. The species occurs on only two rivers on the Forest, at abundances far lower than historical levels. Because the majority of potential habitat lies within or near the Frank Church-River of No Return Wilderness, anthropogenic impacts to habitat due to activities on the Forest are expected to be minor now and into the future. However, restricted passage to and from the ocean due to hydroelectric dams in the Columbia and Snake Rivers can prevent lamprey from completing their life cycle stages and is the primary factor affecting the persistence of Pacific lamprey in Idaho. Considering the implications of this threat in combination with the species’ restricted range, low population size, decreasing population trends, and low ability to recover from disturbance, the Pacific lamprey is recommended as an SCC.
Evaluator(s): Lindsay Chipman and Bart Gamett
Forest Recommendation: This analysis indicates there is substantial concern for the capability of Entosphenus tridentatus to persist over the long-term on the Salmon-Challis National Forest. Therefore, it is recommended that Entosphenus tridentatus be designated as a Species of Conservation Concern.