Ocean Water and Ocean Life. Salinity ◦ total amount of solid material dissolved in water ◦...
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Transcript of Ocean Water and Ocean Life. Salinity ◦ total amount of solid material dissolved in water ◦...
Salinity◦ total amount of solid material
dissolved in water◦ Expressed in parts per thousand◦ Mostly sodium chloride
Sources of Sea Salt◦ Chemical weathering of rocks on
the continents◦ The Earth’s Interior
Decrease Salinity◦ Precipitation◦ Sea ice melting◦ Icebergs melting◦ Runoff from land
Increase Salinity◦ Evaporation◦ Formation of sea ice
Surface water temperature varies with the amount of solar radiation received
Thermocline is the layer of ocean water between about 300 meters and 1000 meters where there is a rapid change of temperature with depth
Density is defined as mass per unit volume
Seawater density is influenced by two main factors: ◦Salinity◦temperature
Pycnocline is the layer of ocean water between about 300 meters and 1000 meters where there is a rapid change of density with depth
3 main zones – surface zone, transition zone, and deep zone
Surface Zone◦ Shallow (300 to 450 meters)◦ Zone of mixing◦ Sun-warmed zone
Transition ZoneBetween surface layer and deep zoneThermocline and pycnocline
Deep ZoneSunlight never reaches this zoneTemperatures are just a few degrees above freezingConstant high-density water
Marine organisms can be classified according to where they live and how they move.
Planktonall organisms—algae(Phytoplankton),
animals(Zooplankton), and bacteria—that drift with ocean currents.
Nektonanimals capable of moving independently
of the ocean currents (swimming, etc)Benthos
organisms living on or in the ocean bottom
Three factors are used to divide the ocean into distinct marine life zones:the availability of sunlightthe distance from shorethe water depth.
Availability of SunlightThe photic zone is the upper part of the ocean into
which sunlight penetrates.
Intertidal Zone◦ strip of land where the land
and ocean meet and overlap Neritic Zone
◦ extends from the low-tide line out to the shelf break
Oceanic Zone◦ beyond the continental shelf
Zone where seawater seeps into the ocean floor through cracks in the crust.water temperatures of 100oC or higher support
communities of organisms found nowhere else in the world
Primary productivity is the production of organic compounds from inorganic substances through photosynthesis or chemosynthesis