Ocean The open ocean is the most extensive region on earth.

The open oceans are the areas away from the coastal boundaries and above the seabed ( oceanic crust). It encompasses the entire water column of the seas and the oceans and lies beyond the edge of the continental crust. The open oceans are the areas away from the coastal boundaries and above the seabed ( oceanic crust). It encompasses the entire water column of the seas and the oceans and lies beyond the edge of the continental crust.

CHARACTERISTICS 70% of the planet’s surface is covered by water 70% of the planet’s surface is covered by water Average depth of the ocean: 3000 meters Average depth of the ocean: 3000 meters Life in the oceans is distributed over 3 dimensions Life in the oceans is distributed over 3 dimensions There is a very high diversity of marine environments There is a very high diversity of marine environments

OUR OCEANS Atlantic Pacific Indian Arctic “ONE OCEAN” All are interconnected thanks to an important system of oceanic currents both at surface and in the depths.

Primary Production (gC/m 2 /year) Notice how productive certain areas are, like the North Sea, a region intensly fished!

What limits life in the Oceans? Temperature Temperature –Influences the quantity of O 2 dissolved in the water –Influence on ocean currents Salinity Salinity –Importance for marine animals’ capacity for osmoregulation (process by which we control the quantities of minerals in our cells). –Along with Tº has an influence on water density Sunlight (necessary for photosynthesis) Sunlight (necessary for photosynthesis) Nutrients (ditto) Nutrients (ditto)

Light DEPTH REMINERALIZATION PHOTOSYNTHESIS Euphotic layer Receives enough light for photosynthesis Aphotic layer Total Darkness Oligophotic layer Dusk Zone PROBLEM: PHOTOSYNTHESIS REQUIRES LIGHT + NUTRIENTS, BUT LIGHT IS FOUND IN THE UPPER LAYER WHEREAS NUTRIENT-RICH WATERS ARE NEAR THE BOTTOM! SOLUTION: UPWELLINGS + STORMS (mix up the water column)

Nekton Pelagos Benthos Vertical Distribution of Life Plankton

Benthos Communities that live asociated with the ocean floors (from the coast to the deep trenches) Communities that live asociated with the ocean floors (from the coast to the deep trenches)

Plankton cocolithophorids Phytoflagellates

Zooplankton The CONSUMERS You don’t want to know how many of these you can swallow in a bucket full of sea water…

Other crustaceans krill amphipod Many animals that live on the sea floor actually live in the water column as plankton when they’re young. As they grow older and bigger (and go through several metamorphosis) they migrate back down to the bottom.

Echinoderm larvae (sea urchin) Molluscs

Medusas

Nekton Animals who live in the water column and are capable of travelling independantly from the currents Animals who live in the water column and are capable of travelling independantly from the currents Examples: Examples: Cefalopods (squid, cuttlefish…)

Fish

Marine Mammals and Reptiles

Human Impact Humans have a lot of 'waste' that is often disposed of in the ocean - trash, sewage, oil, chemicals, heat, and even 'noise' to name a few.

Human Impact Over fishing Climate change Oil spills Noise pollution Habitat destruction Introduction of alien species Sewage and trash

1.Which are colombian oceans? 2.Have you even been in the ocean? 3. What do you like most of oceans? 4.What problem did you observ? 5.If you go to the beach, what advices will you give to people around to take care the ocean region? 6.Draw a Colombian map and color in blue the ocean region in our country, in green the tropical rain forest and in yellow the deserts.