Sardine Spawning Habitat Estimation

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Sardine Spawning Habitat Estimation

• Dave Checkley
• Pete Davison
• Rebecca Asch
• Ryan Rykaczewski

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Objective

• Optimally predict the potential spawning habitat
  of sardine, by maximally explaining variation in
  sardine egg distribution (CalVET, CUFES, bongo,
  manta) with explanatory variables including
  geography (lat, lon, bathymetry), hydrography
  (T,S, SSH), particle distributions (OPC and
  LOPC), zooplankton displacement volume (bongo,
  manta, CalVET), and acoustic backscatter (ADCP,
  EK-500)

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Methods

• ANOVA
• Kernel Density Estimation
• Variogram
• Regression

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Data

• Initial focus 1998-2004
• Sardine eggs (CUFES, CalVET, bongo, manta)
• Lat, long, T, S, bottom depth
• Displacement volume (bongo, manta)
• Scattering (ADCP EK-500 zplk fish)
• LOPC (upcast biovolume)

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Variable PlotsPete Davison
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Kernel Density EstimationPete Davison
Spawning habitat of anchovy, estimated from KDE
using temperature, salinity, and bottom depth (x)
and the distribution of anchovy eggs measured by
the Continuous Underway Fish Egg Sampler, CUFES
(o).
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SSH as an index of SSHRebecca Asch
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SSH as an index of SSHRebecca Asch
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SSH as an index of SSHRebecca Asch
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SSH as an index of SSHRebecca Asch
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SSH as an index of SSHRebecca Asch
Effects of eddies located within a given habitat
on the presence/absence and concentration of
sardine eggs. Results indicate that eggs are
less abundant inside eddies in offshore and
coastal habitats in comparison with adjacent
areas.
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SSH re Wind Stress CurlRyan Rykaczewski
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Spawning Habitat

• Planque, B., E. Bellier, and P. Lazure. 2007.
  Modelling potential spawning habitat of sardine
  (Sardina pilchardus) and anchovy (Engraulis
  encrasicolus) in the Bay of Biscay." Fisheries
  Oceanography 16(1) 16-30. Differentiated between
  'potential spawning habitat', defined as habitat
  where the hydrographic conditions are suitable
  for spawning, 'realized spawning habitat',
  defined as habitat where spawning actually
  occurs, and 'successful spawning habitat',
  defined as habitat from where successful
  recruitment has resulted.

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Reiss, C. S., D. M. Checkley, and S.J. Bograd.
2008. Remotely sensed spawning habitat of Pacific
sardine (Sardinops sagax) and Northern anchovy
(Engraulis mordax) within the California Current.
Fish. Oceanogr. 17(2) 126-136.