Patterns in Primary and Secondary Production Flashcards
How does phytoplankton biomass change throughout the year in the tropics?
It doesn’t
How does phytoplankton biomass change throughout the year in the north temperate?
High in spring, low in summer, fall bloom, low in winter
How does phytoplankton biomass change throughout the year in the north polar?
Low at all times of the year except in the summer
How do sunlight and nutrients change throughout the year in temperate oceans?
Winter: Sunlight lowest, nutrients highest
Spring: sunlight increase, nutrients decreasing
Summer: Sunlight highest, nutrients lowest
Fall: sunlight decreasing, nutrients increasing
What are the grazing effects on phytoplankton biomass?
Copepods are the main grazers of large phytoplankton cells, but blooms may be dependent on zooplankton biology (life cycles - i.e. zooplankton reproduce more slowly than phyto)
What areas have the highest net primary productivity?
Upwelling zone, continental shelf, open ocean (lowest net, but most total global production)
What are fronts?
Relatively narrow regions characterized by large horizontal gradients in variables such as temp, salinity, density
What causes fronts?
Currents going around Islands, tides through narrow pass
How do anticyclonic gyres spin in NH and SH and what are their characteristics?
NH: clockwise
SH: anticlockwise
Convergent, downwelling, low production
How doe cyclonic gyres spin in NH and SH and what are their characteristics??
NH: anticlockwise
SH: clockwise
Divergent, upwelling, higher production
Where does continental divergence occur and what is it?
West of continents, upwelling and high productivity
Where does continental convergence occur and what is it?
East of continents, coral reefs, downwelling
What are examples of large scale patchiness?
Coastal regions, river-plume fronts, shelf-brake fronts, tidal fronts
What are examples of small scale patchiness?
Langmuir circulation, deep scattering layer (diel vertical migration)
What are langmuir circulation cells?
Helical convection cells in the topmost 6m of the water column due to wind which are circular in cross section. Converging currents produce a series of parallel linear aggregations of plankton at the surface
