Marine pollution

1. Marine pollution
Marine pollution or Ocean pollution which is caused due
to waste being dumped into such water bodies affects the
biological processes of the marine ecology.
Eighty percent of marine pollution comes from land.

2. Sources of pollution
Land-based sources
 Agricultural run-off
 Municipal and industrial wastes
Sea-based sources
 Oceanic dumping
 Offshore oil spills

3. POINT AND NON-POINT SOURCES
1. Point source – refers to a single identifiable source of pollutants
eg. effluent outfall
2. Non-point source – refers to diffuse source of pollutants eg. Acid
rain, dust storms
NONPOINT SOURCES
POINT
SOURCES
Urban streets
Suburban
developmen
t
Wastewater
treatment
plant
Rural homes
Cropland
Factory
Animal feedlot

4. 1. Operational discharge from tankers during tank cleaning
2. Bilge discharge from all vessels
3. Spills due to marine accidents i.e., collision, grounding,
explosion
4. Spills during loading
5. Deliberate discharge of sewage, garbage etc.
Marine pollution from vessels can be divided into five categories:-

5. DISCRETE VS. CHRONIC POLLUTION
 Discrete (short term) – eg. an oil spill, the effects of which
diminish with time
 Chronic (long term) – eg. nutrient input, effluent discharge
Types of pollution

6. Types of pollution
Pollution
Oil
(Petroleum
hydrocarbons)
Eutrophication
Conservative
Metals
Halogenated
hydrocarbons
Thermal
Radioactive
Litter &
Plastic debris

7. Oil pollution
Sources
62%
1%
10%
7%
3% 15%
2%
Industrial waste
Refineries/Terminals
Natural sources
Tanker operations
Tanker accidents
Other shipping
Offshore
Source: UNEP

8.  Impacts on living resources
 Hazards to human health
 Hindrance to marine activities
 Impairment of quality of seawater
 Reduction of amenities
 Loss of aesthetic beauty
 Impacts on the sensitive habitats
General impacts
Marine pollution

9. Oil pollution
Oil pollution is mostly used to
describe marine oil spills, where oil
is released into the ocean or coastal
waters.
Oil spills are due to the following:
 crude oil from tankers
 offshore platforms
 drilling rigs and wells
 spills of refined petroleum
products (such as gasoline, diesel)
 spill of any oily refuse or waste
oil
Oil Pollution:-

10. OTHER SOURCES OF OIL POLLUTION
 Ballasting / deballasting operation of tankers
 Discharge of oily bilge water
 Tank washing
 Refinery effluents
 Discarded lubricants and minor sources
 Accidents to tankers and other vessels
 Offshore exploration and exploitation
 Accidents to pipelines and terminals
 Natural seepages

11. Chocolate mousse
Tar balls
Oil pollution

12.  Effects – Impairment of marine life
 Plankton, esp. neuston at highest
risk – exposed to water soluble
components leaching from oil
 Fixed vegetation –Sea grass beds–
killed or flowering inhibited
 In Mangroves – lenticels clogged
with oil oxygen level in sediments
drops – death
 Sea birds –buoyancy and thermal
insulation lost
Oil pollution
Impacts

13. Eutrophication
“The enrichment of water by nutrients, especially nitrogen
and/or phosphorus, causing an accelerated growth of algae
and higher forms of plant life to produce an undesirable
disturbance to the balance of organisms present in the water
and to the quality of water concerned”

14. Eutrophication
 Wastewater effluent (municipal and
industrial)
 Runoff and leachate from waste
disposal systems
 Runoff from agriculture/irrigation
Runoff from pasture and range
 Runoff from mines, oil fields,
unsewered industrial sites
 Overflows of combined storm and
sanitary sewers
 Untreated sewage
Sources

15.  Over-productivity
 Reduction in phytoplankton
species diversity
 Growth of harmful algal
blooms
 Reduction in dissolved oxygen
content
 Anoxia and mass mortalities of
marine organisms
Impacts
Eutrophication

16.  Conservative pollutants tend to be stable, long-lived
compounds that persist within the environment.
 Non-conservative pollutants can transform or degrade
into other compounds, but the rate of transformation
depends on the physical, chemical, and biological
conditions occurring within the receiving water
environment.
Conservative pollutants

17. Conservative pollutants - Metals
 A heavy metal is a member of a loosely-defined subset of
elements that exhibit metallic properties.
 It mainly includes the transition metals, some metalloids,
lanthanides, and actinides.
 There is an alternative term for heavy metal and is called as
toxic metal
 The major sources of metals are:
 Natural sources
 Manmade sources

18.  Erosion of ore-bearing rocks
 Atmospheric inputs - wind blown
dust
 Volcanic activity
 Forest fires
 Riverine inputs into oceans
Conservative pollutants - Metals
Natural Sources

19.  Industrial discharge
 Sewage
 Re-suspension of sediments by dredging and trenching
Conservative pollutants - Metals
Manmade Sources

20. Metal Natural sources
(in thousand
tonnes/year)
Anthropogenic
sources
(in thousand
tonnes/year)
Arsenic 12 18
Cadmium 1.3 7.6
Copper 28 35
Lead 12 332
Nickel 30 56
Zinc 45 132
World-wide emissions (Clark, 2001)
Conservative pollutants - Metals

21. Arsenic (As)
 Phytoplankton most sensitive & accumulate from water
column
 Higher trophic levels accumulate via food.
Cadmium (Cd)
 Divalent cadmium is more toxic
 Tends to bioaccumulate
Lead (Pb)
 Forms strong complex with clay and suspended material
 Bioaccumulates in most marine organisms – no
significant problems.
Conservative pollutants - Metals
Impacts

22. Source
Pollution from plastic plant- dumped
mercuric chloride into the bay
Impact
 Shellfishes contaminated with
mercury
 People who consumed shellfish
severely affected
 43 dead and 700 permanently
disabled
 Bay is still unusable for fishing and
shell fishing
Conservative pollutants - Metals

23. Bioaccumulation
 Increase in concentration of a substance(s) in an organism or a
part of that organism
 The affected organism has a higher concentration of the
substance than the concentration in the organism’s
surrounding environment
 Not excreted or metabolised and failure of the target organ

24.  Also called bioamplification
 Increase in concentration of a substance in a food chain,
not an organism
Biomagnification

25.  Hydrocarbons containing chlorine, fluorine, bromine or
iodine.
 Differs from petroleum hydrocarbons – not degraded by
chemical oxidation or by bacteria
 Low molecular weight compounds
– eg., Dichloroethane, Freons etc.
 High molecular weight compounds
– eg., DDT, Drins, PCBs
Conservative pollutants –
Halogenated hydrocarbons

26. Aerial transport
 Aerial spraying of pesticides as aerosols – travel great
distances
Freshwater inputs
 Rain washing of pesticides carried into sea by rivers
 Silt from flood
Direct inputs
 By industrial outfalls – especially by Pesticide manufacturing
companies.
Sources
Conservative pollutants –
Halogenated hydrocarbons

27.  Low solubility in water persist for long durations
 Fat-soluble , so incorporated into the tissue of marine
organisms and sediments
 Lethal to the animal
 Possibility of transmission through food webs – established in
a number of animals
Impacts
Conservative pollutants –
Halogenated hydrocarbons

28. Thermal pollution
 Thermal pollution is the degradation of water quality by any
process that changes ambient water temperature.
OUTFALL FROM QURRAYAH POWER PLANT, SAUDI ARABIA

29. Thermal pollution
Sources
 Industrial wastewater
 Power plant discharges
 Desalination plant discharges
 Urban runoff

30.  Thermal shock
 Decrease in dissolved oxygen
 Increase in photosynthesis
 Increase in metabolic rate of fish
 Increase in oxygen consumption
Thermal pollution
Impacts

31. Radioactive pollution
 Radioactive wastes are usually by-products of nuclear
power generation and other applications of research and
medicine.
 Radioactive waste is hazardous to human health
 Pollution due to radioactive wastes – Radioactive
pollution

32.  Weapons testing – Testing of
nuclear weapons – when
exploded underwater release
fission products and isotopes
 Liquid wastes – Discharge from
the cooling water of nuclear
reactors
 Solid wastes – Dumping of
radioactive wastes in Sea (now
no longer practiced).
Radioactive pollution
Sources

33.  Highly lethal - Even low doses causes fatal damage
 Possibility of bioaccumulation – especially in algae and
bivalves
eg. Porphyra near a nuclear power plant location
had 10 times more caesium-137 than in the
surrounding waters
Radioactive pollution
Impacts

34. LITTER AND PLASTICS POLLUTION
 Marine litter, is human created
waste that has deliberately or
accidentally become afloat in a
the sea or ocean.
 It tends to accumulate at the
centre of gyres and on
coastlines, frequently washing
aground, when it is known as
beach litter or tide wrack.

35. LITTER AND PLASTICS POLLUTION
Sources
 Up to 80% of the pollution is land-based.
 A wide variety of anthropogenic artifacts can
become marine debris
 Plastic Bags, Balloons, Buoys etc.

36. LITTER AND PLASTICS POLLUTION
Impacts
 Many animals that live on or in the sea consume flotsam by
mistake, as it often looks similar to their natural prey
 Blocks the passage of food and causing death through
starvation or infection.
 Tiny floating particles also resemble zooplankton, which
can lead filter feeders to consume them and cause them to
enter the ocean food chain.
 In samples taken from the North Pacific Gyre in 1999 by
the Algalita Marine Research Foundation, the mass of
plastic exceeded that of zooplankton by a factor of six.

37. SOLUTION TO POLLUTION
 Reduce input of toxic pollutants
 Treat sewage primary, secondary and tertiary treatment
 Ban dumping of wastes and raw sewage in the sea
 Ban ocean dumping of sludge and hazardous dredged material
 Protect sensitive areas from development, oil drilling, and oil
shipping
 Regulate coastal development