Of the major routes of contamination for the aquatic environment, the most significant are directly from treated and untreated waste waters, run-off and atmospheric deposition (including spray drift) and indirectly from leaching.rinking water is derived from either surface waters or groundwater. The latter is of enormous importance, with more than 65% of Europe's drinking water needs being supplied in this way. However, water from either source is rarely, if ever, pure. Industrialization and urbanization together with intensified agricultural activity have led to increased demands for water on the one hand but to the potential for large scale release of contaminants on the other. The result is that surface water can be contaminated through direct or indirect emissions and groundwater can be contaminated by leaching from the soil. The diversity and number of existing and potential sources of chemical contamination are quite large.

1. AN ASSIGNMENT OF
AQUATIC TOXICOLOGY:-

2. ROUTES OF
ENTRANCE OF
POLLUTANTS IN
AQUATIC
ECOSYSTEMS
PRESENTED BY
M. AHMED RAZA

3. Submitted By M. Ahmed Raza
Roll# 591606/2208
Department Zoology
Course Aquatic Toxicology
Submitted to Ma'am Shahida Tabassum
Govt. Postgraduate College of Science, Samanabad, Fsd.

4. CONTENTS
:-
• What is aquatic ecosystem?
• Types of aquatic ecosystems.
• Pollutants of aquatic ecosystems.
• Routes of entrance of pollutants in aquatic
ecosystems
i. Industrial Releases
ii. Pharmaceutical pollution
iii. Oil Pollution
iv. Dredging
v. Pesticides
vi. Marine Litter
• References

5. WHAT IS AQUATIC
ECOSYSTEM
• Aquatic ecosystems are an umbrella term for all ecosystems
that exist in water.
• A water-based environment, wherein, living organisms interact
with both physical and chemical features of the environment.
• An ecosystem is a community of organisms that live and
interact within a particular environment. In an aquatic ecosystem
, that environment is water, and all the plants and animals in the
system live either in, on or around that water.

6. TYPES OF AQUATIC ECOSYSTEMS
There are two major types of aquatic ecosystems:
1. Marine Ecosystems
Marine ecosystems can be defined as the interaction of plants, animals,
and the marine environment. Over 70% of Earth’s surface is covered in
water, and 97% of that water is salt water, marine ecosystems are the
largest types of ecosystems on the planet.
2. Freshwater Ecosystems:
Aquatic ecosystems including lakes, rivers and wetlands make up the
world’s freshwater ecosystems. They are characterized by a lower salt
content than that which occurs in marine ecosystems
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7. POLLUTANTS OF AQUATIC ECOSYSTEMS:-
There are many sources of pollutants to the
fresh and marine ecosystems. It is estimated
that 80% of marine chemical pollution
originates on land.
• Waste incineration.
• Coal-fired power stations.
• Fossil fuel production release tons of
hazardous emissions into the atmosphere every
year.
• Combustion of fuels in automobiles
• Factories, and smelters introduces
hydrocarbons and metals into the environment.

8. ROUTES OF
ENTRANCE OF
POLLUTANTS
IN AQUATIC
ECOSYSTEMS...
....

9. INDUSTRIAL
RELEASES:-
Industrial facilities continue to release millions of
kilograms of toxic chemicals into rivers, streams, lakes,
and ocean waters each year. For example, in 2010, U.S.
industrial facilities dumped 226 million pounds
(approx. 102.5 million kilograms) of toxic chemicals
into American waterways. According to the federal
government’s Toxic Release Inventory, toxic chemicals
were discharged to more than 1,900 waterways in all 50
states. Approximately 1.5 million pounds were linked
to cancer, while 619,000 pounds of chemicals were
linked to developmental disorders, and approximately
342,000 pounds were reproductive toxins.. Pulp and
paper, iron and steel, energy supply, non-ferrous
metals, and chemicals industries have some of the
highest releases direct to water

10. PHARMACEUTICAL
POLLUTION:-
• Recently, the substances in the ocean that have gotten the
most attention – because they have shown up at disturbingly
high levels in some fish – are toxic pharmaceutical chemicals.
The pharmaceutical industry (nicknamed Big Pharma) has
soared in recent years, improving the health of people around
the world. There is no denying that there are numerous and
incredible benefits of modern pharmaceuticals. The flip side of
this, though, is that many of those prescribed pharmaceutical
products are disposed of incorrectly and end up in the Earth’s
waters, having a negative effect on our oceans as well as on the
animals that live within them.
• "The ocean is basically a toilet bowl for all of our chemical
pollutants and waste in general," says Chelsea Rochman, an
Assistant Professor of the Department of Ecology and
Evolutionary Biology at the University of Toronto. "Eventually,
we start to see those contaminants high up in the food chain, in
seafood and wildlife."
•

11. OIL POLLUTION
• Oil spill, leakage of petroleum onto the surface of a large body of
water. Oceanic oil spills became a major environmental problem in the
1960s, chiefly as a result of intensified petroleum exploration and
production on continental shelves and the use of supertankers capable of
transporting more than 500,000 metric tons of oil. Spectacular oil spills
from wrecked or damaged supertankers are now rare because of stringent
shipping and environmental regulations. Nevertheless, thousands of
minor and several major oil spills related to well discharges and tanker
operations are reported each year, with the total quantity of oil released
annually into the world’s oceans exceeding one million metric tons. The
unintentional or negligent release of used gasoline solvents and
crankcase lubricants by industries and individuals greatly aggravates the
overall environmental problem. Combined with natural seepage from the
ocean floor, these sources add oil to the world’s waterways at the rate of
3.5 million to 6 million metric tons a year.

12. DREDGING ON THE
MARINE ENVIRONMENT
• Dredging is an activity that is required to be carried
out to remove the unwanted deposits from water
pathways. But even though the activity aids regularity
in marine traffic, it is not without its disadvantages.
Dredging possess a huge threat to the marine
environment.
• Since dredging loosens up the soil, those substances
which were previously held fast to the contaminated
deposit will find their way into the water and the un-
dredged soil. If these substances are harmful organisms
then they will cause a substantial degradation to the
environment even after dredging the area
• The water could get polluted because of the soil
particles mixing with the water. And while this does not
have huge biodiversity impacts, it is indeed an
unwanted side-effect of dredging

13. ROLES OF PESTICIDES
The aquatic ecosystem consists of various groups of
organisms such as invertebrates, plants, microorganisms, fish,
or amphibians. Pesticides can affect these organisms directly
or indirectly; the direct effect includes physiological changes
within an organism [57-59]. For example, the exposure of
pesticides to water flea results in their mortality, which can be
considered as the direct effect of pesticides, and it may lead to
the drastic increase in the biomass of algae because of release
from the grazing pressure considered as an indirect effect.

14. ROLES OF PESTICIDES
• Both in fish species, as well as aquatic flora and fauna, are exposed to
a variety of pesticides in three common ways as dermal, direct absorption
all the way through integument by swimming in contaminated surface
water with pesticide as well as subordinate surfaces of waters in form
of lentic and lotic water bodies, direct or indirect uptake of pesticides
through inhalation by the way of gills during respiration, and directly
throughout, drinking pesticides contaminated water or feed pesticide
contaminated prey.
• The sources of pesticides in the aquatic system through the
agricultural runoff and industrial effluents, the entire foreign toxic
compound mixed in the aquatic ecosystem and disturbed all aquatic life.

15. MARINE LITTER
• Marine litter is any persistent, manufactured or processed
solid material discarded into the sea or rivers or on beaches;
brought indirectly to the sea with rivers, sewage, storm water
or winds; or discarded or lost at sea. Marine litter poses
environmental, economic, health, aesthetic and cultural
threats, including degradation of marine and coastal habitats
and ecosystems that incur socioeconomic losses in marine-
based sectors.
• Marine litter is a transboundary challenge that is rooted in
unsustainable production and consumption patterns, poor
solid waste management and lack of infrastructure, lack of
adequate legal and policy frameworks and poor enforcement,
including on interregional cross-border trade of plastic
waste, and a lack of financial resources.
•

16. REFERENCES
• https://ipen.org/transfer/embargo/aquatic_pol
lutants_in_oceans_and_fisheries_ipen-en.pdf
• https://www.nationalgeographic.com/environm
ent/article/plastic-pollution
• https://www.unep.org/cobsea/what-we-
do/marine-litter-and-plastic-pollution
• https://www.toppr.com/guides/science/nature
/ecosystem/aquatic-ecosystem-definition-
and-its-types/
• https://www.researchgate.net/publication/333
990907_Impacts_of_pesticide_application_on_a
quatic_environments_and_fish_diversity