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Marine Food Chains/Webs. Energy from primary production is transferred up the trophic chain Each step is inefficient (~90% energy is lost) Shorter chains are more efficient at producing apex predators. Bottom Up Control on the Marine Food Webs. h n. CO 2. O 2. Phytoplankton. Food Web. - PowerPoint PPT Presentation
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Marine Food Chains/Webs
• Energy from primary production
is transferred up the trophic
chain
• Each step is inefficient (~90% energy is lost)
• Shorter chains are more
efficient at producing apex
predators
Bottom Up Control on the Marine Food
Webs
Primary Secondary Production Production
Phytoplankton
h
CO2 O2
PlantsNUTS FoodWeb
Marine Food Chains/Webs
• Energy from primary production
is transferred up the trophic
chain
• Each step is inefficient (~90% energy is lost)
• Shorter chains are more
efficient at producing apex
predators
Primary Production by Biome
Ryther (1969) Science
Primary Production by Biome
Ryther (1969) Science
Marine Food Chains/Webs
• Open ocean = 90% area & most of
the NPP but little fish
production
• Coastal ocean = 9.9% area & 20%
of the global NPP but ½ of the
fish production
• Upwelling systems = 0.1% area &
little NPP but ½ fish
production
CalCoFI Zooplankton Sampling
Dudley Chelton [OSU]
CalCoFIZooplankt
on
Seasonal Zooplankton
Zoo
Winds
Seasonal Zooplankton
Zoo
Winds
CalCoFI Zooplankton
Highest in the tongueof CA Current
The Upwelling Conveyor Belt
Highest NUTS
High NUTSLow NUTS
High Chl Low ChlLower Chl
High Zoo Low ZooLower Zoo
Sinking POM
CalCoFI Zooplankton
Correspondsto low salinitywaters fromnorth
CalCoFI Zooplankton
Highest in the tongueof CA Current
The Upwelling Conveyor Belt
Highest NUTS
High NUTSLow NUTS
High Chl Low ChlLower Chl
High Zoo Low ZooLower Zoo
Sinking POM
CalCoFIZooplankt
on
Hi Zoo’s = Low Temp
ENSO connection
All in pre-1977
CalCoFI Zooplankton
70% Decline in 1970’s
The 1977 Regime Shift
McGowan et al, 1998: Climate-Ocean Variability and Ecosystem Response in the Northeast Pacific, Science
Cool vs. WarmWater Species
T. Spinifera = cool water
N. Simplex = warm
Cool water species – gone during ENSO
Zooplankton in CA Current
• Zooplankton follow climatic
changes both ENSO and PDO are seen
• Long term zoo distribution
consistent with upwelling conveyor
& advection from N Pac
• Evidence of species switching is
also observed
