Sources and effects of oil pollution in marine environment

1. SOURCES AND EFFECTS OF OIL
POLLUTION IN MARINE ENVIRONMENT

2. INTRODUCTION
An oil spill is the release of a liquid petroleum
hydrocarbons into the environment due to human
activity . And is a form of pollution. The term is
usually applied to marine oil spills.

3.  Coming to oil which is also a potential hazard, take for
example, the Torrey Canyon Disaster. This oil tanker
ran a ground in the English channel on march,18,1967.
Spilling 95000 tonnes of its cargo of 117000 tonnes of
crude oil into the sea.
 Many efforts are made to destroy the oil. The royal air
force even dropped incendiary bombs in order to burn
the split oil, but failed.
 We know that oil is highly inflammable and crude oil is
mixture of 100’s of different chemicals, ranging from the
highly volatile petrol with a low flash point to the viscous,
tarry, high Boiling point components. The volatile petrol
quickly evaporates from the sea water leaving other
hydrocarbons difficult to burn.

4. CONTD…
 Detergents emulsify the oil, which breaks up into small
drops. Will mix with sea water, it increasing the
poisonous effect of the oil , they do not remove it thus
the oil will come out of its emulsify state and affect area
again
 The oil can also be removed from the sight by using
pulverized chalk and sodium stearate or by sand plus
fuel ash coated with silicon compound to make it. But
this arms the creature living at the sea bottom.
 The toxicity of fuel is 20ppm for fish and 0.4 – 0.6ppm
for other marine animals, the rates of degradation by
natural means vary from 36 – 350 micrograms/sq.m per
year. The isoprenoids, olicyclic and aromatic compounds
of crude oil have also been detect.

5.  Even after 1.5 years of 600 tonns of oil split into
sea, the mud of bottom of the sea contain 70mg of
hydrocarbons per kg of mud.
 Many bacteria eat components of the oil, but no
single bacteria can decompose all the components
of the oil. Now possible to combine to produce
various different bacteria as super germ. Which are
breaking of all the components of crude oil. This
process is much prefer than the nature
biodegradation of oil, and it is eco-friendly.
Ex: Pseudomonas

6. DISASTERS GULF OIL SLICK
 The massive oil slick in the gulf has happened on
Feb. 1990 due to Iran – Iraq war.
 Gulf water standing at more than 330 milion gallons
is polluted by oil 30 times more than the quantity
spilled by the Exxon Valdez on the shores of
Alaska.
 The oil slick stiches over an area of 80km long and
20km wide moving towards south at a speed of
20km a day, the oil spill hit the saudi shores and is
now threatening the shores Bahrain, Qatar, Kuwait
and united Arab emirates.

7. BOMBAY HIGH OIL SLICK
 On may 17, 1993 the Uran oil pipe line ruptured at
an off shore platform causing a 4 km long and 400
meters wide massive oil spill in Bombay.
 The national institute of oceanography, Goa to
conduct an in-depth enquiry into the damage to eco
system and marine life.
 The WIO used research ship Sagara Kanya, they
reported it may take as many as five years for the
eco system to recover from the disaster.
 ONGC estimated that the cubic meters of oil spilled
had caused the company a set back of 1 crore at
the rate of 18 $ per barrel.

8. PHYSICAL EFFECTS OF OIL IN WATER
 Reduction in dissolved oxygen – oil films are
able to retard significantly the rate of oxygen uptake
by water.
 Reduction in light penetration – oil slick
decreases the light intensity upto 90% only 2
meters below the surface of water than in clean
water.
 Smothering – Smothering coats of oil have killed
lichens and algae along the shore line.

10. BEHAVIOR OF OIL SPILL IN MARINE
ENVIRONMENT

11.  Spreading: spreading of oil are due to wind, waves
, currents under the influence of hydrostatic and
surface forces and get thickness of 0.03mm within
24hrs.
 Evaporation: the composition of oil, its surface
area, physical properties ,wind velocity, air and sea
temperature, intensity of solar radiation. All affects
evaporation rates of hydrocarbon.
 Photo-Oxidation: The natural sun light in the
presence of oxygen can transforms several
hydrocarbons in hydroxy compounds such as
aldehydes and ketones

12.  Dispersion- dispersion oil begins dispersing
immediately on contact with water and is most
significant during the 1st ten hours
 Dissolution- dissolution is another physical
process in which the low molecular weight
hydrocarbons as well as polar non-hydrocarbon
compounds are partially lost from the oil to the
water column

13. SOURCES OF OIL POLLUTION IN SEA WATER
 Cargo tanker washing at sea- about 3 million tons
of oil are added annually to the sea by using sea
water as ballast for empty
 Import oil losses- collision in port contribute one
million tone of oil in sea water annually.
 Lubricating oil are added every year in coastal
water, Maritime accidence to collision, fire,
explosure are also result in oil release in sea water.

14. CONTD…
 Oil leakage from 20,000 miles of pipe lines from
which cross water ways may undergo corrosion,
cracks or puncture and would lead to oil pollution in
sea water.
 The blow out of well, disposal of drilling muds,
accidental damages to offshore drilling rings add to
oil pollution in water.
 Recent oil based technology and vessel accidents
near sea shore add to extensive marine oil
pollution.

15. OIL SPILL EFFECT ON WILD LIFE
 Birds loose body weight as their metabolism, tries
to combat low body temperature.
 The most obvious way oil affects birds is my
coating their plumage in sticky grassy slim.
 Birds become dehydrated and can starve as they
give-up or reduce drinking diving and swimming to
look for food
 Hypothermia in birds by reducing or destroying in
the insulation and water proofing property of their
feathers unless to fly.
 It damages the inside of birds and animals bodies
like bleeding, if