OceanOceanThe open ocean is the The open ocean is the

most extensive region on most extensive region on earth.earth.

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

CHARACTERISTICSCHARACTERISTICS

• 70% of the planet’s surface 70% of the planet’s surface is covered by wateris covered by water

• Average depth of the ocean: Average depth of the ocean: 3000 meters3000 meters

• Life in the oceans is Life in the oceans is distributed over 3 distributed over 3 dimensionsdimensions

• There is a very high There is a very high diversity of marine diversity of marine environmentsenvironments

OUR OCEANSOUR OCEANS

AtlanticPacific

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/m2/year)

Notice how productive certain areas are, like the North Sea, a region intensly fished!

What limits life in the What limits life in the Oceans?Oceans?

• TemperatureTemperature– Influences the quantity of OInfluences the quantity of O22 dissolved in the dissolved in the

waterwater– Influence on ocean currentsInfluence on ocean currents

• SalinitySalinity– Importance for marine animals’ capacity for Importance for marine animals’ capacity for

osmoregulation (process by which we control osmoregulation (process by which we control the quantities of minerals in our cells).the quantities of minerals in our cells).

– Along with Tº has an influence on water Along with Tº has an influence on water densitydensity

• Sunlight (necessary for photosynthesis)Sunlight (necessary for photosynthesis)• Nutrients (ditto)Nutrients (ditto)

LightLight

D

EPTH

REM

INER

ALI

ZA

TIO

NPH

OTO

SYN

TH

ESIS

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)

NektonPelagos

Benthos

Vertical Distribution of LifeVertical Distribution of Life

Plankton

BenthosBenthos

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

PlanktonPlankton

cocolithophoridsPhytoflagellates

ZooplanktonZooplankton

The CONSUMERSThe CONSUMERS

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

Other crustaceansOther 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 Echinoderm larvae (sea larvae (sea

urchin)urchin)

MolluscsMolluscs

MedusasMedusas

NektonNekton

• Animals who live in the water Animals who live in the water column and are capable of column and are capable of travelling independantly from the travelling independantly from the currentscurrents

• Examples: Examples:

Cefalopods (squid, cuttlefish…)Cefalopods (squid, cuttlefish…)

FishFish

Marine Mammals and Marine Mammals and ReptilesReptiles

Human ImpactHuman Impact

Humans have a lot of 'waste' Humans have a lot of 'waste' that is often disposed of in the that is often disposed of in the

ocean - trash, sewage, oil, ocean - trash, sewage, oil, chemicals, heat, and even chemicals, heat, and even

'noise' to name a few.'noise' to name a few.

Human Impact

Over fishingClimate changeOil spillsNoise pollutionHabitat destructionIntroduction of alien speciesSewage 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.