This document provides an overview of marine pollution presented in a seminar. It discusses various sources of marine pollution including direct discharge of industrial and urban waste, land runoff carrying pollutants, sewage, pesticides, metallic wastes, ship pollution, atmospheric deposition, and deep sea mining. It also examines different types of marine pollution such as eutrophication, oil spills, radioactive pollution, thermal pollution, and plastic debris. The conclusion emphasizes that marine pollution occurs when chemicals, particles, waste, or invasive species enter the oceans and have harmful effects, disrupting marine food webs and environments.

1. A Seminar
on
MARINE POLLUTION
Presented by
VENKATESHA C K
1st Sem Applied Geology
Guided by
Prof.D.NAGARAJU
DOS in Earth Science
Manasagangotri
Mysore
A Seminar
on

2. • Introduction
• Sources of marine pollution
• Direct Discharge
• Plastic Debris
• Sewage
• Metallic wastes
• Ship Pollution
• Deep sea mining
• Types of marine Pollution
• Atmospheric Pollution
• Acidification
• Eutrophication
• Oils spills
• Radioactive Pollution
• Thermal Pollution
• Conclusion
• Reference

3. Term ‘Pollution' describes the occurrence and inputs
of wastes and the impact of these wastes on the
environment.
• Marine Pollution:
“The introduction by man, directly or indirectly of
substances or energy to the marine environment
resulting in deleterious effects such as: hazards to
human health, hindrance to marine activities,
impairment of the quality of seawater for various uses
and reduction of amenities.”

4. Direct discharge:
• Pollutants enter rivers and sea directly from urban
sewage and industrial wastes discharges, sometimes
in the form of hazardous and toxic wastes

5. Land runoff :
Surface runoff from farming, as well as urban runoff and
from the construction of roads, buildings, ports, channels, and
harbours, can carry soil and particles laden with carbon,
nitrogen, phosphorous, and minerals.
Polluted runoff from roads and highways can be a
significant source of pollution in coastal areas.

6. Sewage:
Sewage pollution of coastal and estuarine is usually most severe during the
summer when temperatures are raised, river outflows reduced and populations
often increased.
There are three broad categories of discharges:
1. Untreated, containing much solid organic
material together with organic solutes and
some nitrate and phosphate.
2. Partially treated, containing a smaller
proportion of solids, with organic solutes
and a greater concentration of nitrate and
phosphate . The solids are macerated
before discharge.
3. Fully treated, containing virtually no
solid matter, and being mainly a solution
of nitrate and phosphate.

7. • Animal waste and human wastewater
from toilets and other household
activities such as bathing and
laundering as well as food
preparation are often washed directly
into the ocean from coastal
communities. Untreated sewage
contains microbes or pathogens that
precipitate disease when infected
seafood is consumed or skin contact
occurs. In some cases, solid sludge
from treated sewage is also dumped
into the oceans.

8. Pesticides:
• Pesticides are biological active chemicals which are
used for killing pests.
• Pesticides may enter the oceans from the atmosphere
after aerial spraying from overland runoff of sprayed
areas, or from international dumping in the sea.

9. • Certain organochlorine pesticides, notably
DDT(Dichlorodiphenyltrichloroethane), have become
widely dispersed throughout the oceans, even to the
Arctic and Antarctic. They are only very slowly
degraded. Some marine organisms, especially
crustacea, are extremely sensitive to both
organochlorine and organophosphorus compounds
are killed by very small concentrations. Because these
compounds are more soluble in fats than in the water.

10. Metallic wastes: Heavy metals are metallic
chemical elements that have a
relatively high density and are
toxic or poisonous at low
concentrations. Examples are
mercury, lead, nickel, arsenic and
cadmium. such toxins can
accumulate in the tissues of
many species of aquatic life in a
process called bioaccumulation,
which results in more toxicity in
fish. When we consume such
fishes, it will affect our nervous
system, kidney, brains,
respiratory system or even it will
lead us to death.

11. Ship pollution:
Ships can pollute waterways
and oceans in many ways. Oil
enters water from breakdowns on
derricks, wrecks of oil tankers,
accidental spillage, cleaning of
fuel tanks by merchant and war
ships, and also from street
cleaning. Discharge of cargo
residues from bulk carries can
pollute ports, waterways and
oceans. Oil spills can have many
devastating effects. While being
toxic to aquatic life in the surface
layers and also the coastal flora
and fauna. Ships also create noise
pollution that disturbs natural
wildlife, and from ballast tanks
can spread harmful algae and
other invasive species.

12. Atmospheric pollution:
Another pathway of pollution occurs through the
atmosphere. Wind blown dust and debris, including
plastic bags seaward from landfills and other areas.
Climate change is raising ocean temperatures and raising
levels of carbon dioxide in the atmosphere. These rising
levels of carbon dioxide are acidifying the oceans.

13. Acidification:
Dissolving carbon dioxide in sea water increases the
hydrogen ion concentration in the ocean, and thus decreases
ocean pH is known as acidification
The oceans are normally a natural carbon sink, absorbing
carbon dioxide from the atmosphere. Because the levels of
atmospheric carbon dioxide are increasing, the oceans are
becoming more acidic. The potential consequences of ocean
acidification are not fully understood, but there are concerns
that structures made of calcium carbonate may become
vulnerable to dissolution, affecting corals and the ability of
shellfish to form shells.

14. Deep sea mining:
All mining operations raise
questions about environment
damages to the surrounding
area. Here in water also the
concern is about disturbance
to the living organisms in the
area, change in sediment or
rock layer of sea floor, change
in toxicity of the water column
and food web. Removal parts
of the sea floor will disturb
the benthic layer. Permanent
disturbance to the habitat of
benthic organisms.

15. Oil spills:
• Hundreds of small and big cases of oil spills occur every year causing
significant ecological damage.
Oil may enter the sea water by number of ways as follows;
• Cargo tanker washing at sea and international discharge of oily wastes from
tank washings
• Bilge pumping at sea
• Import oil losses: collisions in port contribute one million tons of oil in sea
water annually.
• Oil leakage from pipelines
• Oily wastes from oil fields or refiners near the coast.

16. Apart from fouling of
beaches, which if severe can lead to
the destruction of much of the
intertidal population, the major
threat from oil pollution is to
seabirds and mammals. Oil readily
penetrates and mats the plumage of
seabirds, making flight impossible
and leading to loss of oil and gut
irritation. At the present time many
hundreds of thousands of seabirds
are destroyed annually by oil
fouling. The species at greatest risk
are those which live mainly on and
in the water, e.g. puffins, guillemots,
razorbills, shags, cormorants, ducks
and divers..

17. Eutrophication :
“The process by which a body of water acquires a high
concentration of nutrients, especially phosphates and
nitrates. These typically promote excessive growth of algae.
As the algae die and decompose, high levels of organic matter
and the decomposing organisms deplete the water of
available oxygen, causing the death of other organisms, such
as fish. Eutrophication is a natural, slow-aging process for a
water body, but human activity greatly speeds up the
process.”

18. • A large portion and great danger is
non biodegradable plastic
• 46,000 pieces of floating plastic/sq mile
of ocean surface off the N.E U.S. coast.
• Sea turtles mistake plastic bags for
jellyfish and die from internal blockages.
• Seals and sea lions starve after
being entangled by nets or muzzled by
six-pack rings (decomposition time
400 years).
• Plastic debris kills 1,00,000 marine
mammals and 2 million sea birds die
annually.

19. Radioactive pollution:
• Radioactive materials may
enter the sea from two main
sources; from weapon
testing via atmosphere
fallout and from atomic
power industries. Although
power station discharges are
kept very low in
radioactivity, sea foods
should not be collected from
their vicinity. Seaweeds
concentrate radioactive with
great rapidly and fish absorb
a variety of radioactive
substances.

20. • Some highly dangerous
radioactive wastes are
disposed of by dumping
into the deep oceans in
sealed containers. The
fate of these residues is
uncertain. There are
hopes that incorporation
of radioactive wastes into
solid glasses from which
nothing can leach or leak
may prove a safe method
of disposal.

21. Thermal pollution:
• Warm effluents discharged into bays and estuaries may raise the water
temperature. This reduces the solubility of oxygen, and the oxygenation
may be further, reduced by increased oxygen consumption by animals and
bacteria, and by reduced vertical mixing due to thermal stratification. The
effect may be that the underlying layers become deoxygenated and foul.
• Migratory fish, salmon may be discouraged from passing through the area.
Warm water may favour pests, such as shipworm and gribble, accelerating
their growth and extending their breeding seasons, and it may also
encourage the establishment of foreign pests. The fouling rate on ships
hulls is likely to be raised.

22. Conclusion
• Marine pollution occurs when harmful or potentially
harmful, effects results from the entry into the ocean of
chemicals, particles, industrial, agricultural and
residential waste, noise, or spread of invasive organisms.
• When pesticides are incorporated into the marine
ecosystem, the quickly become absorbed into marine
food webs.
• Toxic metals can also be introduced into marine food
webs. These can changes to tissue matter, biochemistry,
behaviour, reproduction, and suppress growth in marine
life.

23. REFERENCE:
Internet References
http://www.mcsuk.org/marineworld/pollution.htl
http://www.oceanlink.island.net/ask/pollution.htl
K. SIDHARTHA,, 2005, OCEONOGRAPHY A BRIEF
INTRODUCTION PP. NO.310-314
J.L.KUMAR, P.C.SINHA ,1998, MARINE POLLUTION, FOR
ANMOL PUBLICATIONS PP.NO 39-69