Water column structure and zooplankton distribution along Trevor Channel, Barkley Sound

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Water column structure and zooplankton
distribution along Trevor Channel, Barkley Sound

• Andrew Hamilton

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• http//collections.ic.gc.ca/

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• Observations
• Strong sound scattering layer at depth
• in Trevor Channel
• Anoxic layer at depth in Trevor Channel
• Shallow sill restrict water mass mixing
• Abundant zooplankton collected during
• net tows

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• Research Question
• Is spatial variability in zooplankton abundance
  and
• distribution related to physical oceanographic
  parameters?
• Observations Required
• Biology Vertical and horizontal patterns of
• zooplankton abundance, biomass, and diversity
• Physics Profiles of temperature, salinity, and
  oxygen

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• Significance
• Zooplankton consume phytoplankton - indication of
  
• Primary Productivity
• Zooplankton consumed by higher trophic levels
• (fish, whales)
• Influence local fisheries, aquaculture,
  ecotourism
• Physical - biological coupling affects entire
  ecosystem
• (productivity, nutrient and carbon cycling)

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• Methods
• 5 station transect along Trevor Channel
• Biology horizontal zooplankton net tows (shallow
  - 5m,
• deep - 10m off bottom (20-170m))
• Zooplankton abundance, biomass, and diversity
• Physics CTD/oxygen profiles

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Trevor Channel

• Open ocean

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• Results
• Zooplankton abundance and biomass highest
• inside Trevor Channel
• Zooplankton diversity highest in open ocean
• Higher abundance and biomass at deep sites

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W
E
Trevor Channel
Open Ocean
Low Salinity
Low Oxygen
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Krill behavior as recorded by acoustic doppler
current profilers in the GullmarsfjordLiljebladh
and ThomassonJournal of Marine Systems (2001)
http//www.awi-bremerhaven.de/Eistour/krill-d.html
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Fig. 5.
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Ice
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• Conclusions
• Zooplankton abundance and distribution is
• related to water mass characteristics
• Physical - biological relationship is complex
• Will directly compare temperature, salinity, and
• oxygen profiles to zooplankton results
• More sampling helpful (vertical stratification,
• duplicate net tows, phytoplankton profiles)

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Acknowledgements Captain John of RV Alta Chris
(for getting dirty) Josie (for tinfoil and lab
work) Rich (for CTD crash course) Maite (for
baking lessons) High School research assistants
(for doing all the work) Thankyou!