P1252109256IDgUH

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Distribution and Life History Characteristics of
Lamprey in lower Columbia River Tributaries
U. S. Fish and Wildlife Service Columbia River
Fisheries Program Office Vancouver, WA Jen
Stone Howard Schaller
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Background

• Pacific lamprey in the Columbia River Basin have
  declined to only a remnant of the pre-1940s
  populations
• Ecological Significance of Lamprey
• Carcasses are a big nutrient supply in
  oligotrophic streams(Beamish 1980)
• Important part of food chain for many species
• Most abundant dietary item for seals and sea
  lions(Roffe Mate 1984)
• Juvenile and adult lamprey buffer against salmon
  predation (Poe et al. 1991, Merrell 1959)
• Emergent ammocetes and eggs eaten by salmon
  (Pfeiffer Pletcher 1964)
• Historic Distribution-throughout Columbia Snake
  coincident with salmon

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Background- continued

• Current Distribution reduced due to dam
  blockages- limited info on reduced distribution -
  no comprehensive survey has been undertaken
• Actions are currently being considered for the
  recovery of Pacific lamprey populations in the
  Columbia River Basin
• Status of the western brook lamprey is unknown
• Few studies on all Lamprey populations in the
  Columbia

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Pacific Lamprey (Lampetra tridentata) Life Cycle
Egg
10K-200K eggs hatch ? 19days
Enter stream July - October
1-4 years in marine environment-external parasites
Adult
Ammocoete
4-6 years as ammocoetes Transform in July-October
Macropthalmia
Migrate to ocean late fall-spring
Outmigrant stage
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Goal for Lamprey Projects

• Develop information on
• Distribution
• Abundance
• Life history
• Limiting factors
• Use information to guide management and
  restoration of Lamprey and their habitats

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Objectives for Year 1

• Identify and survey additional streams in the
  lower Columbia River basin that may be suitable
  study sites to complement ongoing lamprey
• Confer with other agencies to determine potential
  study streams based on areas where previous work
  may have information on Lamprey
• Search agency reports and data bases for
  information pertinent to lamprey and habitats in
  streams
• Conduct field surveys in up to five streams
  identified as potentially suitable for study
  sites
• Select two streams as study sites for future work

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Conduct field surveys

• characterizing aquatic habitats (water velocity,
  depth, substrate size, and canopy density Platts
  et al. 1983).
• sampling for lamprey larvae
• determining access and feasibility of installing
  traps and weirs

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Sampling for lamprey larvae Diagram of Sample
Reach Stratified Point Sampling Technique
Transect 6
10 m
Transect 5
Transect 4
Transect 3
Water Flow
Transect 2
Transect 1
sample point

• Electrofishing
• 70 depletion, 2 pass minimum, 5 pass maximum

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Out Year Objectives

• Abundance and migration timing of adults
• Larval distribution and habitat use
• Outmigrant abundance and migration timing
• Evaluate Spawning habitat requirements

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Anticipated Benefits and Expected Results

• Presently, very little information on these
  Lamprey population
• Better understanding of Lamprey distribution
• Improve our understanding of the population
  dynamics
• Identify limiting factors
• Contrast Lamprey populations in additional
  streams
• Help identify the range of Lamprey population
  status and their habitats in the Lower Columbia
• Help with identifying restoration measures
• Better understanding of ecological significance
  of Lamprey in the Columbia River