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vertical:
epipelagic (top) / euphotic (good)
mesopelagic (middle) / disphotic (low)
bathypelagic (deep) / aphotic (without)
abyssopelagic (bottomless)
plankton (floaters)
nekton (swimmers)
benthos (bottom dwellers)
2% inhabit pelagic environment (most of the oceans are cold and dark)
98% are benthic!
Phytoplankton (plants)
Zooplankton (animals)
Fish
Epiflora or epifauna live on the sea bottom.
Infauna live in the sea bottom.
Benthic plants are restricted to shallow waters because of their requirement for light.
Benthic animals occur everywhere from shallow depths to the deep sea.
life style of a species may change as it ages.
Many benthic animals, e.g., crabs, clams, starfish have a planktonic larval stage.
influence of physical and chemical parameters on organisms in the various ecosystems that constitute the ocean.
An ecosystem includes both the living (biotic) and non-living (abiotic) portions of the environment.
Examples include: salt marshes, estuaries, coral reefs, the North Pacific Gyre.
Temperate and salinity important in controlling growth of organisms, as well as their distribution
It is a function of the density of water and the total heig
ht of the water column.
Pressure generally increases at a rate of 1 atm per 10 m of
water.
Hydrostatic pressure is enormous in the deep sea yet animals
live there.
Animals do not contain gases.
However, mesopelagic fish which have gas-filled swim bladder
s to help maintain neutral buoyancy are unable to move rapidly between
depths because the pressure change could cause the bladder to explode.
a chemical gradient reflecting the concentration of salts inside the body relative to the surrounding seawater is established.
As a result salts will diffuse from an area of high concentration to low concentration.
Diffusion is important in the process of nutrient uptake and the elimination of waste products.
If an animals body fluid is less salty than the suurounding seawater water, water will diffuse out and the animal will dehydrate
If an animals body fluid is more salty water will diffuse in to the body leading to the swelling of cells.
http://dusk.geo.orst.edu/oceans/lec21.html
Divisions of the Marine Environment Figure 9-1
Classification of Organisms by Lifestyle
Scientists have established another classification scheme to categorize biota on the basis of lifestyle. The major groups are:
Distribution of Marine Lifestyles
16.7% of Earths animals are marine
Plankton
Plankton are weak swimmers, and are known as drifters, unable to counteract currents. The group includes:
Nekton
Nekton are active swimmers capable of counteracting currents. The group includes a diversity of organisms including:
Squid
Reptiles
Birds
Mammals
Benthos
The benthos includes organisms attached to or living on or in the sea bed. This group includes plants and animals.
Research Video Clip: Live fast, die young...
and the story of the Tubeworm Barbecue
Varying Lifestyles
Although convenient, there are always exceptions to a classification scheme.
Basic Ecology
factors regulating the distribution and abundance of organisms in the ocean.
Hydrostatic Pressure
Hydrostatic pressure is the pressure caused by the height of
water.
Diffusion: molecules move from high to low concentrations
Diffusion
internal fluids of marine organisms also contain salts
Diffusion (Cont.)
Diffusion is also the mechanism by which water molecules pass through cell membranes. This is called osmosis.
Diffusion/Osmoregulation - Figure 9-12