Life on the Ocean

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Life on the Ocean

• Chapter 13

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• We can define each part of the ocean on the basis
  of the following characteristics
• temperature
• amount of light
• currents
• salinity
• nutrient supply
• water depth
• nature of the sediment on the bottom

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Biomes

• Assemblage of organism,
• Divided into Provinces or biomes
• Two major zones
• Pelagic entire water column
• Neritic over the continental shelve
• Oceanic off the continental shelve
• Benthic entire sea floor

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• Different names depending on whether we are
  considering benthonic (bottom dwellers)
  nektonic (can swim against the current), or
  planktonic (drifters) organisms.

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• Epipelagic Provinces coincides with the
  Eu/photic zone (100-150m)
• (nekton, plankton)
• Benthic Provinces
• Supralittoral
• littoral intertidal (foreshore)

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• sublittoral 0-200 m (continental shelf)
• bathypelagic 1000 m
• bathyal 4000 m (continental slope and rise
  mid-ocean ridges)
• abyssopelagic 4000-6000 m
• abyssal 4000-6000 m (abyssal plains)
• hadalpelagic gt6,000 m
• hadal gt6,000 m (trenches)

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• Most plankton live in the epipelagic, photic
  zone.
• Most light penetrates into the epipelagic and
  littoral to sublittoral zones.
• Some whales and giant squid live in the
  mesopelagic and even into the top of the
  bathypelagic province.
• We still have so much to learn about life in the
  meso-, bathy- and abyssopelagic realms!

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• Dissolved oxygen levels will go down, but plant
  growth will speed up which can raise oxygen
  levels back up during the day, but drive them
  down again at night.

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• All the physical factors together make up a
  province.
• Each province of the ocean then has a unique set
  of plants and animals that are adapted to that
  province.
• The set of plants and animals is a community.
• A community is all of the organisms living in the
  same environment (province) and interacting with
  one another.

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• In the ocean, we see that animals and plants fit
  into one of four basic lifestyles
• planktonic - mero early part of their
  development, holo through their life
• nektonic
• nekto-benthonic
• benthonic - epifauna attached to sea floor,
  infauna within the sea floor

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• Each community has its share of plankton, nekton,
  and benthos.
• The really defining members of most communities
  would be the BENTHOS because some nektonic
  organisms can swim into an area and swim out of
  it again.