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Mary L Moser - One of the best experts on this subject based on the ideXlab platform.
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Providing refuges for adult Pacific lamprey Entosphenus tridentatus inside fishways
Aquaculture and Fisheries, 2021Co-Authors: Mary L Moser, Matthew L. Keefer, Kinsey E. Frick, Christopher C. Caudill, Stephen C. Corbett, Sean C. TackleyAbstract:Abstract Fishways at hydroelectric dams are unnatural environments that typically present fish with channels of uniform depth, variable water velocity, and lack of cover. Fish retention and overall passage success may be improved by providing rest and sheltering areas inside fishways. We examined adult Pacific lamprey Entosphenus tridentatus use of two specially designed fishway refuges at Bonneville Dam on the Columbia River (northwestern USA). These relatively small boxes (1.1 m × 0.4 m × 0.2 m) provided low-velocity, dark refuge from predation for Pacific lamprey, a largely nocturnal species. Refuge boxes were equipped with antennas to detect entry of lamprey tagged with passive integrated transponder (PIT) tags. We PIT tagged and released 3,247 lamprey, including 599 that were double-tagged with a PIT and a radio transmitter, over three study years (2012–2014). In each year, PIT-tagged lamprey detected at nearby fishway exits had used a refuge: 12% in 2012, 28% in 2013, and 36% in 2014. Median residence time of PIT-tagged lamprey in the refuges for each year was 20.3 h, 16.6 h, and 13.1 h. Lamprey entrance into refuges peaked at 0300–0500 PDT, and they typically exited at around 2000 PDT, suggesting that refuges primarily functioned as shelter from daylight. Probability of refuge use increased with a morphological indicator of sexual maturity (distance between dorsal fins). In the radio-tagged group, refuge users were equally likely to pass Bonneville Dam as non-users. However, refuge users were less likely than non-users to be detected at sites upstream from the dam, perhaps owing to their maturation status or longer mean passage time through our study area (2.0 vs. 0.6 d for non-users). Refuges show promise for improving fish retention in fishways, particularly for nocturnal and/or small-bodied species that seek shelter from light or predation.
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Occurrence of pathogens in Pacific lamprey (Entosphenus tridentatus)
Reviews in Fish Biology and Fisheries, 2019Co-Authors: Aaron D. Jackson, Kenneth M. Lujan, Corie Samson, Melissa G. White, Marilyn Blair, Linda Rhodes, Scott Lapatra, Samuel T Onjukka, Mary L Moser, Ralph LampmanAbstract:Pacific lamprey (Entosphenus tridentatus) is a First Food of Native Americans. Declines in lamprey abundance due to dam construction and habitat loss have curtailed traditional harvest opportunities. Artificial propagation is an emerging recovery tool for this imperiled species, and other lamprey species in Finland and Japan. To manage disease risk at prospective lamprey hatcheries, it is critical to understand the pathogens and parasites most likely to affect lamprey and other fish, both in culture and in the wild. We assembled data from regional fish health laboratories to assess pathogen prevalence in Pacific lamprey sampled from various sources (518 adults, 275 larvae, and one juvenile). In adults, Aeromonas salmonicida was identified using standard health screening methods in 0–69% of dead lamprey samples submitted, but no other pathogens were typically observed. All larvae were negative for bacterial and viral infections, and larvae experimentally exposed to A. salmonicida showed no infection or mortality. Conspicuously absent were detailed health assessments for metamorphosed larvae (juveniles). However, external examinations of over 20,000 juveniles captured at dams on the lower Columbia River indicated that they are susceptible to fungal infection in warm water conditions (> 12 °C), which can lead to mortality. To fully evaluate the disease risk associated with lamprey culture, directed research is needed along with standardized health screenings of lamprey at all life stages. Control of A. salmonicida, the etiological agent for furunculosis, will be a top priority for Pacific lamprey use, as this was the only pathogen regularly identified in this species.
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Novel fishway entrance modifications for Pacific lamprey
Journal of Ecohydraulics, 2019Co-Authors: Mary L Moser, Steve C. Corbett, Matthew L. Keefer, Kinsey E. Frick, Siena Lopez-johnston, Christopher C. CaudillAbstract:AbstractPassage facilities at dams must accommodate a broad array of aquatic species to achieve full river connectivity. In an attempt to improve adult Pacific lamprey (Entosphenus tridentatus) pas...
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Climbing success of adult Pacific lamprey on a vertical wetted wall
Fisheries Management and Ecology, 2017Co-Authors: Kinsey E. Frick, S. C. Corbett, Mary L MoserAbstract:The ability of adult Pacific lamprey, Entosphenus tridentatus (Gairdner), to climb has enabled development of lamprey-specific fishways. Sheer vertical climbing elements are needed for these structures when fishway installation space is limited. A 1.6-m high aluminium wetted wall was built to test Pacific lamprey vertical climbing in relation to flow and three water delivery mechanisms: overflow, upwelling and sidewelling. Passage success and passage times were recorded for individual Pacific lamprey (n = 122). For those that interacted with the structure (n = 104), 94% successfully ascended the wall (76% on their first attempt). Average time from first interaction with the structure to exit ranged from 19.5 to 47.0 min. Success rates and passage times were not significantly affected by flow or water delivery treatments. This indicates that vertical elements can facilitate lamprey passage in the 0.13–3.59 L min−1 cm−1 flow range tested and may greatly expand the design alternatives in certain situations.
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Behavioral Responses of Pacific Lamprey to Alarm Cues
Journal of Fish and Wildlife Management, 2017Co-Authors: Laurie L. Porter, Aaron D. Jackson, Mary L Moser, Michael C. Hayes, Brian J. Burke, R. Steven WagnerAbstract:Abstract Pacific lamprey (Entosphenus tridentatus), an anadromous ectoparasite, faces several challenges during adult migration to spawning grounds. Developing methods to address these challenges i...
Margaret F. Docker - One of the best experts on this subject based on the ideXlab platform.
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Landlocked Pacific Lamprey Entosphenus tridentatus in the Middle Fork Willamette River, Oregon
Environmental Biology of Fishes, 2020Co-Authors: Douglas C. Larson, Margaret F. Docker, Matt Helstab, Brian Bangs, Benjamin J. ClemensAbstract:Pacific Lamprey Entosphenus tridentatus is an anadromous fish native to the west coast of North America and the Pacific coast of Asia. In the 1950s, construction of dams on the Middle Fork Willamette River blocked upstream migration of adult Pacific Lamprey which resulted in their extirpation from otherwise suitable habitats. We report evidence of landlocked Pacific Lamprey surviving for >40 years after the construction of two high-head flood control dams (Dexter and Lookout Point) in the Middle Fork Willamette River 355.0 and 360.3 km upstream of the Pacific Ocean, respectively. In 2001, six putative Pacific Lamprey (two juveniles and four larvae) were captured using an electro shocker during a stream survey, 21.7 km upstream of Lookout Point Dam (the uppermost of these dams) and were entered into the Smithsonian National Museum of Natural History’s Division of Fishes collection. We re-examined these specimens, and their morphometric measurements and dentition are consistent with Pacific Lamprey. Additional evidence supports the existence of a landlocked population of Pacific Lamprey that resided upstream of these two impassable dams for approximately five generations. To our knowledge, this is the first report of Pacific Lamprey surviving for multiple generations upstream of impassable impoundments. However, no Pacific Lamprey have been detected in recent targeted surveys, indicating that this population has since been extirpated or exists in very low numbers.
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Conservation Challenges and Research Needs for Pacific Lamprey in the Columbia River Basin
Fisheries, 2017Co-Authors: Benjamin J. Clemens, Margaret F. Docker, Richard J. Beamish, Jeffrey C Jolley, Kelly C. Coates, Jason B. Dunham, Ann E. Gray, Jon E. Hess, Ralph T. Lampman, Brian J. McilraithAbstract:The Pacific Lamprey Entosphenus tridentatus, an anadromous fish native to the northern Pacific Ocean and bordering freshwater habitats, has recently experienced steep declines in abundance and range contractions along the West Coast of North America. During the early 1990s, Native American tribes recognized the declining numbers of lamprey and championed their importance. In 2012, 26 entities signed a conservation agreement to coordinate and implement restoration and research for Pacific Lamprey. Regional plans have identified numerous threats, monitoring needs, and strategies to conserve and restore Pacific Lamprey during their freshwater life stages. Prime among these are needs to improve lamprey passage, restore freshwater habitats, educate stakeholders, and implement lamprey-specific research and management protocols. Key unknowns include range-wide trends in status, population dynamics, population delineation, limiting factors, and marine influences. We synthesize these key unknowns, with a focus on ...
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Simple Genetic Assay Distinguishes Lamprey Genera Entosphenus and Lampetra: Comparison with Existing Genetic and Morphological Identification Methods
North American Journal of Fisheries Management, 2016Co-Authors: Margaret F. Docker, Gregory S Silver, Jeffrey C Jolley, Erin K. SpiceAbstract:AbstractSeveral species of lamprey belonging to the genera Entosphenus and Lampetra, including the widely distributed Pacific Lamprey E. tridentatus and Western Brook Lamprey L. richardsoni, co-occur along the West Coast of North America. These genera can be difficult to distinguish morphologically during their first few years of larval life in freshwater, thus hampering research and conservation efforts. However, existing genetic identification methods are time consuming or expensive. Here, we describe a simpler genetic assay using the Pacific Lamprey microsatellite locus Etr-1; the assay was found to be 100% reliable in distinguishing Entosphenus from Lampetra, even in genetically divergent Lampetra populations. Using a sample of 244 larvae (18–136 mm TL) from the Columbia River basin, we tested the accuracy with which previously described differences in caudal fin pigmentation can distinguish these genera. Attempts at morphological identification were abandoned for 50-mm and smaller larvae because diff...
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Microsatellite DNA analysis of parapatric lamprey (Entosphenus spp.) populations: implications for evolution, taxonomy, and conservation of a Canadian endemic
Canadian Journal of Zoology, 2012Co-Authors: Eric B. Taylor, Les N. Harris, Erin K. Spice, Margaret F. DockerAbstract:Parapatric freshwater and anadromous parasitic lampreys (Petromyzontiformes) from southwestern Vancouver Is- land, British Columbia, have been described as distinct taxa (Vancouver lamprey (Entosphenus macrostomus (Beamish, 1982)) and Pacific lamprey (Entosphenus tridentatus (Richardson, 1836)), respectively), using morphology, life history, and physiology. We tested for genetic differentiation at microsatellite DNA loci between these taxa and similar freshwater para- sitic lampreys from two other lakes. The number of alleles and expected heterozygosity averaged 3.8 and 0.50, respectively, across loci and populations, and anadromous populations were more variable than freshwater populations. Population sub- division was moderate (FST = 0.096, P < 0.001) and 3% of the total variation was found between taxa and 1.7% was found among populations within taxa (both P < 0.001). Parapatric freshwater and anadromous parasitic lampreys separated by a maximum of 40 km were more distinct (mean FST = 0.042) than were anadromous populations located 800 km from one another (mean FST = 0.012). Localities within lakes with parasitic freshwater lampreys, however, showed little differentiation (FST = 0.0-0.08). Our data support recognizing E. macrostomus and E. tridentatus as distinct species, but similar levels of differentiation between these taxa and other freshwater parasitic lampreys suggest a species complex where the taxonomy re- mains unclear.
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Characterization of 12 microsatellite loci for the Pacific lamprey, Entosphenus tridentatus (Petromyzontidae), and cross-amplification in five other lamprey species.
Genetics and molecular research : GMR, 2011Co-Authors: Erin K. Spice, T.a. Whitesel, C.t. Mcfarlane, Margaret F. DockerAbstract:The Pacific lamprey (Entosphenus tridentatus) is an anadromous fish that is of conservation concern in North America and Asia. Data on Pacific lamprey population structure are scarce and conflicting, impeding conservation efforts. We optimized 12 polymorphic microsatellite loci for the Pacific lamprey. Three to 13 alleles per locus were observed in a sample of 51 fish collected from the West Fork Illinois River, Oregon. Observed heterozygosity ranged from 0.235 to 0.902 and expected heterozygosity ranged from 0.214 to 0.750. Cross-species amplification produced 8 to 12 polymorphic loci in four other Entosphenus species and in the western brook lamprey (Lampetra richardsoni). Two loci appear to be diagnostic for distinguishing Entosphenus from Lampetra. These markers will be valuable for evaluating population structure and making conservation decisions for E. tridentatus and other lamprey species.
Benjamin J. Clemens - One of the best experts on this subject based on the ideXlab platform.
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Landlocked Pacific Lamprey Entosphenus tridentatus in the Middle Fork Willamette River, Oregon
Environmental Biology of Fishes, 2020Co-Authors: Douglas C. Larson, Margaret F. Docker, Matt Helstab, Brian Bangs, Benjamin J. ClemensAbstract:Pacific Lamprey Entosphenus tridentatus is an anadromous fish native to the west coast of North America and the Pacific coast of Asia. In the 1950s, construction of dams on the Middle Fork Willamette River blocked upstream migration of adult Pacific Lamprey which resulted in their extirpation from otherwise suitable habitats. We report evidence of landlocked Pacific Lamprey surviving for >40 years after the construction of two high-head flood control dams (Dexter and Lookout Point) in the Middle Fork Willamette River 355.0 and 360.3 km upstream of the Pacific Ocean, respectively. In 2001, six putative Pacific Lamprey (two juveniles and four larvae) were captured using an electro shocker during a stream survey, 21.7 km upstream of Lookout Point Dam (the uppermost of these dams) and were entered into the Smithsonian National Museum of Natural History’s Division of Fishes collection. We re-examined these specimens, and their morphometric measurements and dentition are consistent with Pacific Lamprey. Additional evidence supports the existence of a landlocked population of Pacific Lamprey that resided upstream of these two impassable dams for approximately five generations. To our knowledge, this is the first report of Pacific Lamprey surviving for multiple generations upstream of impassable impoundments. However, no Pacific Lamprey have been detected in recent targeted surveys, indicating that this population has since been extirpated or exists in very low numbers.
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Marine biology of the pacific lamprey Entosphenus tridentatus
Reviews in Fish Biology and Fisheries, 2019Co-Authors: Benjamin J. Clemens, Joy Wade, Laurie Weitkamp, Kevin Siwicke, Julianne Harris, Jon Hess, Laurie Porter, Keith Parker, Trent Sutton, Alexei M. OrlovAbstract:Pacific lamprey Entosphenus tridentatus has an anadromous life cycle that begins with larvae that filter-feed in freshwater, followed by transformation into juveniles that migrate to the ocean where they parasitize hosts, and adults that migrate into freshwater to spawn and die. The marine-phase (i.e., juvenile life stage) is important yet poorly understood, and is associated with growth opportunities to achieve maximum body size and recruitment. The four goals of this paper are to: (1) synthesize the literature to identify patterns in the marine biology of Pacific lamprey; (2) develop hypotheses to explain these patterns; (3) identify limiting factors and threats, and (4) identify research needs. We hypothesize that recruitment of adult lamprey to spawning populations is influenced by oceanographic regimes through impacts on host abundance. Three marine factors that may be limiting lamprey abundance include: (1) predation and fisheries bycatch; (2) host availability; and (3) host contaminant loads. Four potential marine-related threats to lamprey include: (1) pollution; (2) climate change; (3) unfavorable oceanographic regimes; and (4) the effects of interactions between climate and regimes. Pacific lamprey is not philopatric and the extent to which host migrations and other factors influence lamprey entry into rivers is unclear. Research is needed to fill information gaps on how, when, why, and where lamprey move, feed, and grow in the ocean. Their widespread distribution, parasitic life history, diverse hosts, and multiple predators suggest that Pacific lamprey is integrated into diverse marine ecosystems.
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Conservation Challenges and Research Needs for Pacific Lamprey in the Columbia River Basin
Fisheries, 2017Co-Authors: Benjamin J. Clemens, Margaret F. Docker, Richard J. Beamish, Jeffrey C Jolley, Kelly C. Coates, Jason B. Dunham, Ann E. Gray, Jon E. Hess, Ralph T. Lampman, Brian J. McilraithAbstract:The Pacific Lamprey Entosphenus tridentatus, an anadromous fish native to the northern Pacific Ocean and bordering freshwater habitats, has recently experienced steep declines in abundance and range contractions along the West Coast of North America. During the early 1990s, Native American tribes recognized the declining numbers of lamprey and championed their importance. In 2012, 26 entities signed a conservation agreement to coordinate and implement restoration and research for Pacific Lamprey. Regional plans have identified numerous threats, monitoring needs, and strategies to conserve and restore Pacific Lamprey during their freshwater life stages. Prime among these are needs to improve lamprey passage, restore freshwater habitats, educate stakeholders, and implement lamprey-specific research and management protocols. Key unknowns include range-wide trends in status, population dynamics, population delineation, limiting factors, and marine influences. We synthesize these key unknowns, with a focus on ...
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Spawning Patterns of Pacific Lamprey in Tributaries to the Willamette River, Oregon
Transactions of the American Fisheries Society, 2014Co-Authors: Mariah P. Mayfield, Benjamin J. Clemens, Luke D. Schultz, Lance A. Wyss, Carl B. SchreckAbstract:AbstractAddressing the ongoing decline of Pacific Lamprey Entosphenus tridentatus across its range along the west coast of North America requires an understanding of all life history phases. Currently, spawning surveys (redd counts) are a common tool used to monitor returning adult salmonids, but the methods are in their infancy for Pacific Lamprey. To better understand the spawning phase, our objective was to assess temporal spawning trends, redd abundance, habitat use, and spatial patterns of spawning at multiple spatial scales for Pacific Lamprey in the Willamette River basin, Oregon. Although redd density varied considerably across surveyed reaches, the observed temporal patterns of spawning were related to physical habitat and hydrologic conditions. As has been documented in studies in other basins in the Pacific Northwest, we found that redds were often constructed in pool tailouts dominated by gravel, similar to habitat used by spawning salmonids. Across the entire Willamette Basin, Pacific Lamprey...
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Maturation characteristics and life-history strategies of the Pacific lamprey, Entosphenus tridentatus
Canadian Journal of Zoology, 2013Co-Authors: Benjamin J. Clemens, Stan Van De Wetering, Stacia A Sower, Carl B. SchreckAbstract:Lampreys (Petromyzontiformes) have persisted over millennia and now suffer a recent decline in abundance. Complex life histories may have factored in their persistence; anthropogenic perturbations in their demise. The complexity of life histories of lampreys is not understood, particularly for the anadromous Pacific lamprey, Entosphenus tridentatus Gairdner, 1836. Our goals were to describe the maturation timing and associated characteristics of adult Pacific lamprey, and to test the null hypothesis that different life histories do not exist. Females exhibited early vitellogenesis – early maturation stages; males exhibited spermatogonia – spermatozoa. Cluster analyses revealed an “immature” group and a “maturing–mature” group for each sex. We found statistically significant differences between these groups in the relationships between (i) body mass and total length in males; (ii) Fulton’s condition factor and liver lipids in males; (iii) the gonadosomatic index (GSI) and liver lipids in females; (iv) GSI ...
Jeffrey C Jolley - One of the best experts on this subject based on the ideXlab platform.
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a stepwise approach to assess the occupancy state of larval lampreys in streams
Journal of Fish and Wildlife Management, 2020Co-Authors: Julianne E Harris, Gregory S Silver, Jeffrey C Jolley, R D Nelle, T.a. WhiteselAbstract:Abstract Pacific Lamprey Entosphenus tridentatus is an ecologically and culturally important anadromous species of conservation concern for which fisheries managers use information on occupancy sta...
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Pathogens of Pacific Lamprey Detected Through Routine Fish Health Screenings
Journal of Fish and Wildlife Management, 2019Co-Authors: Jeffrey C Jolley, Kenneth M. LujanAbstract:Abstract Interest in conservation, management, and captive rearing of Pacific Lamprey Entosphenus tridentatus in the Pacific Northwest has risen in recent years. General and specific information re...
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Conservation Challenges and Research Needs for Pacific Lamprey in the Columbia River Basin
Fisheries, 2017Co-Authors: Benjamin J. Clemens, Margaret F. Docker, Richard J. Beamish, Jeffrey C Jolley, Kelly C. Coates, Jason B. Dunham, Ann E. Gray, Jon E. Hess, Ralph T. Lampman, Brian J. McilraithAbstract:The Pacific Lamprey Entosphenus tridentatus, an anadromous fish native to the northern Pacific Ocean and bordering freshwater habitats, has recently experienced steep declines in abundance and range contractions along the West Coast of North America. During the early 1990s, Native American tribes recognized the declining numbers of lamprey and championed their importance. In 2012, 26 entities signed a conservation agreement to coordinate and implement restoration and research for Pacific Lamprey. Regional plans have identified numerous threats, monitoring needs, and strategies to conserve and restore Pacific Lamprey during their freshwater life stages. Prime among these are needs to improve lamprey passage, restore freshwater habitats, educate stakeholders, and implement lamprey-specific research and management protocols. Key unknowns include range-wide trends in status, population dynamics, population delineation, limiting factors, and marine influences. We synthesize these key unknowns, with a focus on ...
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Estimation of occupancy, density, and abundance of larval lampreys in tributary river mouths upstream of dams on the Columbia River, Washington and Oregon
Canadian Journal of Fisheries and Aquatic Sciences, 2017Co-Authors: Julianne E Harris, Jeffrey C JolleyAbstract:We estimated occupancy, density, and abundance of larval Pacific lamprey (Entosphenus tridentatus) and Lampetra spp. in tributary river mouths to impounded portions of the Columbia River, Washingto...
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Simple Genetic Assay Distinguishes Lamprey Genera Entosphenus and Lampetra: Comparison with Existing Genetic and Morphological Identification Methods
North American Journal of Fisheries Management, 2016Co-Authors: Margaret F. Docker, Gregory S Silver, Jeffrey C Jolley, Erin K. SpiceAbstract:AbstractSeveral species of lamprey belonging to the genera Entosphenus and Lampetra, including the widely distributed Pacific Lamprey E. tridentatus and Western Brook Lamprey L. richardsoni, co-occur along the West Coast of North America. These genera can be difficult to distinguish morphologically during their first few years of larval life in freshwater, thus hampering research and conservation efforts. However, existing genetic identification methods are time consuming or expensive. Here, we describe a simpler genetic assay using the Pacific Lamprey microsatellite locus Etr-1; the assay was found to be 100% reliable in distinguishing Entosphenus from Lampetra, even in genetically divergent Lampetra populations. Using a sample of 244 larvae (18–136 mm TL) from the Columbia River basin, we tested the accuracy with which previously described differences in caudal fin pigmentation can distinguish these genera. Attempts at morphological identification were abandoned for 50-mm and smaller larvae because diff...
Damon H Goodman - One of the best experts on this subject based on the ideXlab platform.
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Screen Efficiency and Implications for Losses of Lamprey Macrophthalmia at California’s Largest Water Diversions
North American Journal of Fisheries Management, 2016Co-Authors: Damon H Goodman, Stewart B. Reid, Rene C. Reyes, Brent B. BridgesAbstract:AbstractWe investigated the guidance efficiency of fish screens for the protection of emigrating Pacific Lamprey Entosphenus tridentatus and Western River Lamprey (also known as River Lamprey) Lampetra ayresii in a series of experimental trials. All trials were conducted at the Tracy Fish Collection Facility, located in the Sacramento–San Joaquin River Estuary at the entrance to one of the world’s largest surface water diversions. Using 1,200 lamprey macrophthalmia, we tested for the effect of screen type, time of day, and channel water velocity to guide their swimming behavior to avoid entrainment. We found overwhelming evidence for an effect of screen type on efficiency, whereby all lampreys were successfully guided to a holding tank when a vertical traveling screen was used. This was likely due to the small pore size of the screen relative to lamprey sizes. In contrast, the efficiency of louvers, a behavioral screen designed for salmonids, varied by the interaction of time of day and channel velocity. ...
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Free-swimming speeds and behavior in adult Pacific Lamprey, Entosphenus tridentatus
Environmental Biology of Fishes, 2016Co-Authors: Stewart B. Reid, Damon H GoodmanAbstract:Lampreys are extremely efficient anguilliform swimmers, well–designed for long–distance travel, although they are frequently characterized as poor swimmers when compared to salmonids. We examine free–swimming adult Pacific Lamprey, Entosphenus tridentatus , in a raceway environment to approximate swim speeds and behaviors that may occur in the natural environment. Lampreys (mean Body Length 59.2 ± 3.0 cm, range 50–66 cm BL) traveled upstream at a mean groundspeed of 0.34 ± 0.188 BL/s ( n =126, range 0.01–0.79 BL/s). Swimming activity was strongly nocturnal. Observed speeds in the lower range may have been the result of swimming in midwater against faster currents, indirect paths or rest periods. Lampreys generally took advantage of lower near–bottom current velocities by swimming within 6 cm of the bottom, where currents were substantially lower. Equivalent swim speeds, without currents, would be 0.49 ± 0.190 BL/s (range 0.17–0.96 BL/s). These speeds are in the high range of daily travel rates encountered in tagging studies of both Pacific Lamprey and Atlantic Sea Lamprey, Petromyzon marinus , but compare well when migration is limited to hours of darkness or tracking was continuous. Such rates suggest that, travelling only at night, lampreys would cover 1,000 km upriver in under four months. It is crucial that managers and designers incorporate the swimming capability, near–bottom association, utilization of boundary flow conditions, and nocturnal behavior of lampreys into their activities if we are to effectively manage in-stream facilities and conserve these key anadromous species.
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Pacific Lamprey in Coastal Drainages of California: Occupancy Patterns and Contraction of the Southern Range
Transactions of the American Fisheries Society, 2016Co-Authors: Stewart B. Reid, Damon H GoodmanAbstract:AbstractPacific Lamprey Entosphenus tridentatus have been overlooked historically in fish surveys using standard salmonid methods along the Pacific coast of North America. As a result, little is known of even their broader distribution patterns at the drainage level. Over the last 2 decades, the species has shown a northward range contraction of over 900 km, and at this time the southernmost population is the Big Sur River in California. This study evaluates the hypothesis that Pacific Lampreys do not typically utilize relatively small coastal drainages ( 100 km2, but in only 3 of 29 drainages 50 km2, and primarily fr...
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Detectability of Pacific Lamprey Occupancy in Western Drainages: Implications for Distribution Surveys
Transactions of the American Fisheries Society, 2015Co-Authors: Stewart B. Reid, Damon H GoodmanAbstract:AbstractThe historical North American range of Pacific Lamprey Entosphenus tridentatus extends from the northern Baja California of Mexico to Alaska and inland in suitable habitat as far as there is access to the sea. The population of Pacific Lamprey has declined recently, yet we know little about its actual distribution, and that distribution is changing as the species declines in abundance. We evaluated detection and occupancy probabilities for Pacific Lamprey over a broad region encompassing a wide range of landscapes and drainage sizes. We analyze 110 sites, each representing individual drainages or major subdrainages from the southern border of British Columbia to San Francisco, including over 1,900 km of coastline and the Columbia River basin. Using lamprey-specific electrofishers in suitable habitat low in a drainage we found detection probability of ammocoetes at single sites in occupied drainages was generally high at >90%. If not initially detected, then two additional sites provided >95% confi...
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The punctuated seaward migration of Pacific lamprey (Entosphenus tridentatus): environmental cues and implications for streamflow management
Canadian Journal of Fisheries and Aquatic Sciences, 2015Co-Authors: Damon H Goodman, Stewart B. Reid, Nicholas A. Som, William R. PoytressAbstract:We investigated emigration timing of juvenile Pacific lamprey (Entosphenus tridentatus) over a 10-year period in the Sacramento River, California, USA. Emigration was punctuated with 90% of macrophthalmia in daily catches of at least 50 individuals. Macrophthalmia were observed primarily between November and May, with among-year variation in median emigration date over four times that of sympatric anadromous salmon. Our best model associating catch and environmental factors included days from rain event, temperature, and streamflow. We found strong evidence for an association of catch with days from rain events, a surrogate for streamflow, with 93% of emigrants caught during an event and the two subsequent days. Emigration was more likely during nighttime during subdaily sampling after accounting for the effects of factors significantly associated with daily catch. These results emphasize the importance of natural variation in streamflow regimes and provide insight for management practices that would bene...