Chapter 1 - Introduction to Aquatic Pollution

Dr. Ong Meng Chuan

School of Marine Science & Environment

Universiti Malaysia Terengganu

Chapter 1: Introduction to Aquatic Pollution

Aquatic Pollution | MMS 3202 2

CHAPTER 1 INTRODUCTION TO AQUATIC POLLUTION

What make the EARTH different with other planets?

Answer: WATER

Water is essential for life and the most precious substances.

Human can survive for weeks without food, but only a few days without water.

Marine and aquatic environments are the homes for a diverse array of organisms.

Without water, these organisms would not survive.

Water also is needed for agriculture, industry, transportation and a host of other

human uses.

MAJOR WATER COMPARTMENTS

Nearly all the worlds water is the OCEANS.

Only about 0.02% of the worlds water is in a form accessible to human and

organisms that rely on fresh water.



FRESHWATER SHORTAGE

Clean drinking water and basic sanitation are

necessary to prevent communicable diseases and to

maintain a healthy life.

For many of the worlds poorest people, one of the

greatest environmental threats to health remains the

continued use of polluted water.

EXAMPLE : Mali 88% of the population lacks clean

water; Ethiopia 94%.

More than 2/3 of the worlds households have to fetch

water from outside the home.

POLLUTION

Simple definition :

Environmental damage cause by wastes discharged into aquatic system

Complex definition :

Introduction by human, directly or indirectly, of substances or energy into aquatic

environment (including rivers, lakes, estuaries, seas) which resulting in such

deleterious effects as :

o Harmful to living resources

o Hazards to human health

o Hindrance to aquatic activities including fishing, impairment of quality for use

of water and reduction of amenities

Water pollution is any contamination of water

with chemicals or other foreign substances

that are detrimental to human, plant, or

animal health.

These pollutants include fertilizers and

pesticides from agricultural runoff; sewage

and food processing waste; lead, mercury, and

other heavy metals; chemical wastes from

industrial discharges; and chemical

contamination from hazardous waste sites.



Virtually all types of water pollution are harmful to the health of humans and

animals.

Water pollution may not damage our health immediately but can be harmful after

long term exposure.

Different forms of pollutants affect the health of animals in different ways

All the waters in the world are affected by pollution.

The highest mountain streams have been impacted by acid rain. Pollutants are

added from these mountains starting points and spread throughout the watershed

to areas where the rivers flow into the sea.

Lakes, groundwater, and wetlands are all affected by either point or nonpoint source

pollution.



TYPE OF POLLUTANT

Litter left behind or carelessly tossed away chemicals such as

pesticides and fertilizers, and oil-based products seeping into

the watersheds from industry and pleasure vehicles all

impact marine and aquatic environments.

Runoff from highways, parking lots, city streets, bridges, and

heavily populated coastal areas is washed into nearby

watersheds and adds its detrimental effects to the ecosystem.

Until approximately fifty years ago, most pollution was not

seen in our oceans, since it was comprised mainly of metal

and glass, which sink; and paper and cloth, which decay.

Today, pollution is more visible because many of the

manufactured objects are made of plastics, which are light-

weight, strong, and very durable.

Not only do plastics as they are commonly produced degrade

slowly, but some animals see plastics as food and ingest them,

or they become entangled in them. In either case, the result is

usually death.



Heavy metals from industrial processes can accumulate in nearby lakes and rivers.

These are toxic to marine life such as fish and shellfish, and subsequently to the

humans who eat them.

Heavy metals can slow development; result in birth defects and some are

carcinogenic.

Industrial waste often contains many toxic compounds

that damage the health of aquatic animals and those who eat

them.

Some of the toxins in industrial waste may only have a mild

effect whereas other can be fatal.

They can cause immune suppression, reproductive failure or

acute poisoning.

Microbial pollutants from sewage often result in infectious

diseases that infect aquatic life and terrestrial life through

drinking water.

Microbial water pollution is a major problem in the

developing world, with diseases such as cholera and typhoid

fever being the primary cause of infant mortality.

Organic matter and nutrients causes an increase in aerobic

algae and depletes oxygen from the water column.

This causes the suffocation of fish and other aquatic

organisms.

Sulfate particles from acid rain can cause harm the health of

marine life in the rivers and lakes it contaminates, and can

result in mortality.



Suspended particles in freshwater reduces the quality of

drinking water for humans and the aquatic environment

for marine life.

Suspended particles can often reduce the amount of

sunlight penetrating the water, disrupting the growth of

photosynthetic plants and micro-organisms.

Not all pollution are harming to the environment especially in the ocean.

Some pollution might be benefiting the marine ecosystem.

NUTRIENT : discharged (certain dose / concentration) especially from river can act

as fertilizer for the aquatic plants.

Somehow, in high concentration, this contaminant can harm marine organisms as

well as aquatic plants.

POLLUTANT

POLLUTANT : Substances which are toxic to aquatic organisms and human.

If the concentration is low in the water, it may not be toxic. When it approaches to

certain level, it become toxic and may kill the organisms.

Two types of pollutants in our modern society :

Introducing substances which are already presence in the aquatic ecosystem such as

chemical nutrients (P and N)

Introducing substance which are new to the environment such as radioactive wastes,

detergents and pesticides

AMBIENT LEVEL ( Background Level )

o Natural occurring level found in the environment.

o Ambient water DO in Redang Island is 5 mg/L and ambient concentration of

ammonium is 0.05 M

CONTAMINATION LEVEL

o Level of concentration is higher than ambient level but no obvious deteriorate

effect is found on the organisms or environment.

o Water DO in Redang Island decreases to 4 mg/L and ammonium increases to 0.2

M



POLLUTION LEVEL

o Level of concentration is much higher than ambient level. It causes harmful

effects (mortality or disease) to the organisms or bad effect to the environment.

o Water DO of Redang Island decreases to 2 mg/L and ammonium increases to 5

M

TYPE OF POLLUTANT

Various types of pollutants can be identified as followed :

Disposal of domestic sewage, industrial and agriculture waste.

Deliberate and operation discharge of shipborne pollutants.

Interference with the marine environment from the

exploration and exploitation of marine material.

Disposal of radioactive waste from the uses of nuclear energy.

Military use for the ocean

CATEGORIES OF POLLUTANT

Biodegradable Wastes

o Degraded in natural process / can be broken down microorganism or other

living things.

o Oxidative process and ultimately break down organic compounds to stable

inorganic compounds such as CO2 , H20 and NH3.

o EXAMPLE :

Urban sewage

Agricultural waste

Food processing waste

Chemical

Non-Biodegradable Wastes / Conservative Wastes

o Most of this poison either non-degradable or degrade only very slowly in the

natural environment.

o Non-degradable pollutant not only accumulate but are often biologic magnified

as they move in biochemical cycle and long food chain.

o EXAMPLE :

aluminum cans, mercurial salts, long chain chemical and DDT.

Heavy metals ; mercury, copper, lead, zinc

Halogenated hydrocarbons; DDT chlorinated hydrocarbon pesticides, PCBs

polychlorinated biphenyls



Solid Wastes

o Inert solid wastes include litter (man-made plastics, polythene containers nylon

ropes, fishing gear, polystyrene).

o Plastic is a large amount and danger of solid waste. Plastic is not biodegradable.

Sea turtles mistake plastic bags for jellyfish and die from internal blockages.

o EXAMPLE :

Dredging spoil

Mining waste

Industrial waste ; powdered ash (fly ash) from power stations and clay waste

SOURCE OF POLLUTANT

Two sources of pollutants

o Point sources

o Non-point sources

Point sources

Point sources of pollution occur when harmful substances are emitted directly into a

body of water.

Refers to the discharge of pollutants from a discernible (identified), confined, and

discrete conveyance such as a pipe, conduit, channel, or tunnel. (Sewage pipes, open

forest burning, factories effluents.)

Oil spill best illustrates a point source water pollution



Non-point sources / Diffused sources

Non-point source delivers pollutants indirectly through environmental changes.

Non-point type is when fertilizer from a field is carried into a stream by rain, in the

form of run-off which in turn effects aquatic life

Pertains to the input of pollutants from dispersed, diffuse, and uncontrolled sources

such as general surface runoff, groundwater seepage, and atmospheric fallout. (Acid

rains, haze, particles in the air)

SOURCE OF POLLUTANT IN OCEAN

Direct Outfalls

o The most obvious inputs of material to the sea are through pipes discharging

directly into it.

o Urban and industrial wastes discharged directly into the estuary without

treatment became foul, stinking.

o Coastal mariculture direct input of unconsumed feed, fish excrete, pesticides to

inshore waters.



River Inputs

o River flow via their estuaries to the sea.

o Organic wastes organic load entering the sea from upstream.

o Pesticides and fertilizer from agriculture and forestry washed off by rain.

o Petroleum and oil washed from roads by rain enter the sewerage system and

storm water carry them into rivers and to the sea.

Shipping

o Ships carry many toxic substances (oil, liquefied natural gas, pesticides,

industrial chemicals ).

o Shipwrecks and accidents at sea may release these substances Oil tanker

wrecks.

o Oily ballast water and bilge water and cargo tank washings.

Offshore inputs

o A verity of material is dumped at sea in designated dumping grounds.

o Dredging spoil from shipping channels particularly from industrialized estuaries

may contain heavy metals and other contaminants barged out to sea and

dumped.

o Offshore industrial activities oil exploration and minerals mining



Atmospheric inputs

o Discharges to the atmosphere are returned to the land or the sea in rain or if

particulate in nature as fallout.

o Gaseous wastes dissolve directly in the sea at its surface.

o Vehicle exhausts containing leaded petrol.

o Volcanic activity and burning fossil fuels (coal) input of mercury.

AQUATIC POLLUTION IN MALAYSIA

The major pollutants in Malaysia are :

Domestic Sewage

o Nutrient (N & P) loading to the rivers, estuaries and coastal waters cause

eutrophication and Red-Tides organisms toxicity.

o Heavy metals, oil and suspended particles Toxicity to organisms especially to

benthic organisms.

o Pathogenic microorganisms outbreak of human diseases.

Siltation (Suspended particles)

o Suffocate organisms especially to the benthic organisms



Industrial Wastes

o Heavy metals, organic solvents, toxic organic and inorganic chemicals, acids and

alkaline.

o Some of them are highly toxic to aquatic organisms.

o They will cause high mortality to organisms and contaminated the foodchains.

Agriculture Wastes (Pesticides & Nutrients)

o Pesticides are the most toxic chemicals especially to fish.

o The short-term and long-term effects of pesticides will cause great damage to

our aquatic resources.

Petroleum hydrocarbons

o Hydrocarbons especially its aromatic fractions are high toxic to organisms and

the oil contaminated seafoods may cause cancer to consumers.

Chapter 1 - Introduction to Aquatic Pollution

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