marine biomes Flashcards
what influences primary productivity in the ocean?
- availability of nutrients
- amount of sunlight
what is productivity like in the oceans every season?
- winter: short days, low light -> low productivity
- spring: phytoplankton bloom, but quickly use up nutrients and then low productivity
- summer: strong thermocline means that when nutrients are used up there is low productivity
- fall: thermocline breaks down bringing nutrients up from below -> short-lived phytoplankton bloom
what are the different zones of the ocean based on light availability?
- euphotic
- photic
- aphotic (no light)
what are the different zones of the ocean based on water depth?
- pelagic (sunlight)
- benthic (floor of ocean)
- abyssal (not bottom but super deep)
what are the different zones of the ocean based on distance from land?
- intertidal
- neritic (continental shelf)
- oceanic
what is the euphotic zone?
topmost part of the ocean where light is the strongest
and where nearly all of primary production from photosynthesis occurs
what is the aphotic zone?
lower part of the ocean where very little/no light penetrates
- no living plants, high pressure, low temperature, animals survive by eating detritus or other animals, must adapt to living with no light
where is the peak of NPP in the ocean?
- In euphotic zone, close to shore, 50 feet under because too much light at surface
- over continental shelves
what is the benthic zone?
any sea bottom surface where there is low oxygenation of water, same characteristics as aphotic zone
what is the abyssal plain?
subdivision of the benthic zone. It is the floor of the deepest part of the ocean.
- high pressure
- no light
-very cold
- hard to survive
what is the pelagic zone?
open ocean of any depth
what does depth in the ocean determine?
- light intensity
- temperature
- oxygen concentration (depends on temperature and balance between photosynthesis and respiration)
- pressure
- nutrient concentration (atmospheric input at surface, consumed by organisms at surface and then released in aphotic zone by bacterial decomposition)
how do oxygen and nutrients get to photic zone?
- nutrients levels enriched as they go down
- oxygen levels high at depth because low temperatures and deep current
- upwelling along continental margins brings he nutrient rich waters into photic zone
- can also come from airborne dust and rivers/estuaries
what are the characteristics of the intertidal zone?
where land and ocean overlap
- abundant sunlight
- constant wave action supplies oxygen and nutrients
- food is abundant
- various substrate provides hiding places and surfaces to cling to
what are the characteristics of the neritic zone?
- seaward from the low tide line
- well-oxygenated water
- low water pressure
- stable temperature and salinity levels
- home to synthetic life
