Abiotic Factors

Seawater Temperature

influenced by solar input and water mixing (vertical mixing makes colder deeper water)

solar input diff creates a latitudinal temp gradient (more at equator)

Salinity

the measure of dissolved inorganic solids in seawater (ppt/psu)

can be measured via residence time of chlorine

Major elements

Chlorine and Nitrogen

Residence Time

how long inorganic substances are in the water making constant proportions (elements are in constant concentration throughout the oceans)

Brine pools

like lakes under water

Brackwish water

at land-water interface

Oxygen Concentration

oxygen is added via photosynthesis of phytoplankton and from the atmosphere. highest at surface

amount held decreases with increase of temp & salinity

vertically structured because oxygen decreases with water depth until thermocline. below the thermocline cold and oxygen rich water comes from the poles

Oxygen Minimum Layer

particulate matter settles and microbial decomposition depletes oxygen till oxygen concentration is lowest

Light

is strongest at the surface, so organisms that requires sunlight must be near surface

euphotic (sunlight) zone is strongest, then dysphotic (twilight), then aphotic (midnight) has the least