Upwelling, Phytoplankton, and Blue Whales…….

Thermohaline circulation (thermo=temperature, haline=salt)

• Water in the ocean is in motion: the wind pushes it around.• As currents move towards cold areas it gets colder (denser)• The wind evaporates water but not the salt seawater becomes also saltier denser• Denser surface water sinks• Currents at bottom of ocean move “packs” of water with different densities (combination of salt and temperature) around the globe THERMOHALINE CIRCULATION

UpwellingRemains of dead organisms sink and

decompose and go out of the sunlight (epipelagic )zone.

Nutrients accumulate in deep waters Upwelling=process of deep, nutrient-rich

bottom waters flowing to the surface of the oceanhttp://marine.rutgers.edu/mrs/research/upwelling.html

How does it work?Wind + Coriolis force coriolis animation= current flowN-hemisphere: right of wind directionS-hemisphere: left of wind direction“gaps” are filled with water from below:

upwelling

UpwellingWhen the nutrients reach surface water, tiny

algae (water plants) called phytoplankton can grow. These plants are the basis of the ocean food chain.

Upwelling areas are therefore very important for all animal life: shrimp to blue whales

Blue WhalesBiggest animal on earth: 100-

150 tonsMarine mammalsEat tiny animals named krill:

more than 4 tons/dayDepend on areas where they

can find lots of food, like upwellings

Source: http://www.youtube.com/watch?v=fOMzFFh3rEA