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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.
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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 hn CO2 O2 Phytoplankton Food Web NUTS Plants Primary Secondary Production Production
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
CalCoFIZooplankton Dudley Chelton [OSU]
Seasonal Zooplankton Zoo Winds
Seasonal Zooplankton Zoo Winds
CalCoFI Zooplankton Highest in the tongue of CA Current
The Upwelling Conveyor Belt Lower Zoo High Zoo Low Zoo Lower Chl High Chl Low Chl Low NUTS High NUTS Sinking POM Highest NUTS
CalCoFI Zooplankton Corresponds to low salinity waters from north
CalCoFI Zooplankton Highest in the tongue of CA Current
The Upwelling Conveyor Belt Lower Zoo High Zoo Low Zoo Lower Chl High Chl Low Chl Low NUTS High NUTS Sinking POM Highest NUTS
CalCoFIZooplankton 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
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