[C] Open Seas

• The epipelagic zone is associated with the euphotic zone, high in photosynthetic activity
• Plankton - movements change their position, but the current moves their location

  Nekton - ability to swim against strong currents

  Seston - any particle suspended in the sea
• Living seston - plankton

  Nonliving seston - tripton

  • Plankton and tripton occur concurrently as seston
  • Implications - plastics are eaten when plankton are eaten
• Phytoplankton - primary producers

  Zooplankton - heterotrophic, eukaryotic

  Bacterioplankton - archaeans and bacteria

  Viriplankton - free viruses, most abundant
• In higher latitudes, plankton diversity goes down, but biomass goes up
• Plankton classifications in terms of motility

  • Akinetic
  • Viruses, diatoms, foraminiferans
  • Kinetic
  • Most plankton
  • Move by flagella or jet propulsion
• Planktons in terms of size (Traditional)

  • Macroplankton
  • Visible to the naked eye, exceed 1mm
  • Microplankton
  • Could be caught with standard plankton net
  • Nanoplankton
  • Centrifuge plankton
  • Pass through plankton nets
• Planktons in terms of size (Modern) - FPNMMM

  • Femtoplankton
  • Less than 0.0002 mm
  • Picoplankton
  • Less than 0.002 mm
  • Nanoplankton
  • Less than 0.02 mm
  • Microplankton
  • Less than 0.2 mm
  • Mesoplankton
  • Less than 20 mm
  • Macroplankton and Megaplankton
  • 200 - 2000 mm
  • Sargassum weed, larval fishes, jellyfish
• Plankton in terms of spatial distribution

  • Neritic
  • Low latitudes, shallow waters
  • Meroplankton
  • Nauplius and cyprid larvae of barnacles
  • Oceanic
  • Less diverse in diatoms
  • More salps, larvaceans, sea butterflies
  • Neuston
  • Close to the water surface
  • Pleuston
  • Neuston that extend above the surface
• Translucent, cobwebby aggregates of marine microbes

  Marine snow
• Mixed group of zooplankton and fishes that gives a false image of a surface hanging in midwater

  Deep scattering layer
• Vertical migration

  • Singular upward migration at sunset, single downward migration at sunrise
  • Reasons:
  • Energy conservation
  • Avoidance of predators
  • Exploitation of different currents