1. Each year, millions of tons of pollutants from human activities
(industrial, agricultural, urban ) are discharged into rivers and oceans or
contaminate ground water . Polluted water is becoming a serious threat
to human health as well as animal and plant life.

2. 1- AGRICULTURAL POLLUTION
Agriculture is a major source of water pollution .
Leached by rain water , pesticides , chemicals , join
streams through runoff and contaminate infiltration. It's
the same with chemical or natural fertilizers. Excess
spread, they are not eliminated and become harmful to the
environment.

3. 2 – THE INDUSTRY
In the world, many still reject plant directly into the water,
seas or rivers highly polluting and hazardous waste (mercury,
arsenic ... ) . Today more and more countries adopt laws
prohibiting the discharge of these waste streams. Nuclear power
plants create for their thermal pollution by pouring hot water
into rivers , disrupting the environment.

4. 3 - ACID RAIN
Many gas pollutants are released into the air by factories
and cars. Rain water is acified to their contact, killing trees
,attacking the stone and polluting waterways where it
pours .

5. 4 - THE OIL SPILLS
These gigantic oil slicks drifting are usually due to one or
more leaks in the bunkers of a tanker accident. Thousands
of species die poisoned. Oil permeates the shoreline of a
thick black layer in which the birds englute. To rid the oil
sea , it is sucked by pumps after being encircled with
inflatable tubes . Some bacteria are also used to "eat" oil.
The sea will at best a decade to recover.

6. 5 ALGAE - INVASIVE
One of the fertilizers (chemical fertilizers, manure ... ) in
the field can cause algae blooms in rivers and on the coast.
This is called a green tide. Deprived of light and oxygen ,
other species can not grow.

7. 6 - TOO WASTE
Millions of tons of waste
(plastic , cans ... ) pollute rivers and
oceans. At sea, the plastic bags are
terrible havoc among dolphins and
turtles mistake them for jellyfish
and choke by swallowing them . In
the Pacific Ocean , it was found a
true island of plastic waste , formed
by currents, with an area equal to
that of France ! In water, the plastic
takes between 100 and 500 years to
unravel.