the content explains about different types of aquatic ecosystems with different terminologies, it also helps us to understand the marine lives better.

1. NAME :- KRAMIKA UNIYAL
ROLL NO. :- 1916107
SUBJECT:- ENVIRONMENTAL SCIENCE AND ENGINEERING
SUBJECT CODE:- CE102
TOPIC :- AQUATIC ECOSYSTEM
MINI PROJECT FOR ENVIRONMENTAL SCIENCE
AND ENGINEERING
AQUATIC ECOSYSTEM
1.What is an ecosystem?
An ecosystem is a region with specific and recognisable landscape forms such as grasslands,
wetlands, forests, deserts, coastal areas etc. The nature of an ecosystem depends on its
geographical features such as mountains, water bodies, river, lains, hills etc. It also epends on the
climatic conditions such as amount of sunlight, rainfall, temperature. These two factors along with
the soil characteristics constitutes the abiotic part of the ecosystem. These conditions will support a
community of plants and animals which will easily adapt in this environment. The living
component of ecosystem constitues its biotic components. These biotic components interact with
their abiotic component collectively forming an ecosystem.
An ecosystem can be defined completely through these terminologies :-
● Abiotic components:- Temperature, sunlight, moisture, wind, soil characteristics, geographical
conditions etc constitute the abiotic components of the ecosystem.
● Biotic components:- The biotic components of an ecostem are:-
● Producers :- Also known as phytoplanktons are the plants since they derive their energy through
from sunlight and this energy is then consumed by herbivores.
● Primary consumers :-They are the herbivores that feed on producers for their survival.
● Secondary consumers :- They are those carnivores which depend on the primary consumers to meet
their food and energy requirements.
● Decomposers :- They are the detrivores and hence break down the dead organic matter into simpler
substances so that plants can absorb these nutrients.
● Food chain :-A food chain depicts the relationship between different organisms in an ecosystem as
how do they depend on each other to meet their food and energy requirements.
● Food web :-In an ecosystem there are a large number of food chains and all these food chains
collectively form a food web for that ecosystem.
● Ecological pyramid :- An ecological pyramid defines relationship between different organisms f
different trophic level in an ecosystem. These are of three types:-
● Ecological pyramid of number :- It depicts the number of individual organisms at each trophic
level of food chain.
● Ecological pyramid of biomass :- The biomass of the members of the food chain present at any
time flows the pyramid of biomass.
● Ecological pyramid of energy :- An energy pyramid illustrates how much energy is needed as it
flows upwards to supply the next trophic level.
● Ecological succession :- It is defined as the process by which the structural, functional and biotic
community of an ecosystem changes due to change in its physical, chemical and biological
characteristics.
The ecosystems can be broadly classified into two types:-
Terrestrial ecosystem such as forests, grasslands, deserts.
Aquatic ecosystem such as ponds, lakes, rivers, marine ecosystems.

2. AQUATIC ECOSYSTEM
Aquatic ecosystems constitue the marine environment of sea and fresh water in lakes, ponds, rivers
etc. It provides us a wealth of useful natural resources. They provide goods that people collect for
food such as fish and crustacea(crabs). In aquatic ecosystems plants and animals live in water.
These species are adapted to live in different types of aquatic habitat. The special abiotic features
are its physical aspects such as the quality of water,which includes its clarity, salinity, oxygen
contentand rate of flow. These ecosystems can either be stagnant or running. The mud/ rocks that
form the bed of the aquatic ecosystem alter its characteristics and influence its plant and animal
species composition.
Types of aquatic ecosystems are :- PONDS, LAKES, RIVERS, MARINE ECOSYSTEMS ETC.
POND ECOSYSTEM
They are shallow water bodies with a depth of 12-15 ft such that the sun rays penetrate to the
bottom permitting the growth of the plants there. They are temporary and has water only in the
monsoon. Most ponds become dry after rains are over and are covered by terrestrial plants for the
rest of the year.
Structural aspects
1. Inorganic aspects:- It consists of CO2, O2, N2, Ca, P and their componds of amino acids.
2. Organic aspects :- Carbohydrates, proteins, lipids etc are present and their amounts are also
estimated for biomass determination.
3. Climatic regims:- The thermal stratification of pond refers to change in the temperature at
different depths in the pond due to change in water's density with temperature. This
variation influences the aquatic life.
4. Abiotic components :- It comprises of factors such as light, temperature, dissolved oxygen
content, CO2, pH, turbidity etc.
5. Biotic components :- Ex. During monsoons, phytoplanktons such as algae grows on which
microscopical animals(insects) feed on and these insects in turn are eaten by small fishes
which further are eaten by large fishes. Here, Producer is algae, primary consumers are
insects, secondary consumers are small fishes and tertiary consumers are large fishes.
6. Pond cycle :- When insects, worms, snails feed on the waste excreted by animals and the
dead or decaying plant and animal matter, detritus is broken down into nutrients which
aquatic plants absorb through their roots.
Functional aspects
1. Food chain :- ALGAE-------> INSECTS------->SMALL FISHES------>LARGE FISHES
2. Food web :-

3. 3. Ecological succession :-During the rains a pond begins to fill and an ecosystem is formed
but as soon as the monsoons are over these temporary ponds tend to dry and the surrounding
grasses and terrestrial plants entirely cover the exposed moist mud.
LAKES ECOSYSTEM
They are way more larger and deeper than the ponds. Algae are the most abundant and common
phytoplankton in a lake ecosystem.
Structural aspects:-
1. Abiotic components:- Sunlight is penetrated through water to some depth and factors such
as temperature, rainfall, pH constitutes abiotic part os the ecosystem.
2. Biotic components:- The algae forms the major part of producers in this ecosystem which
derives its energy from sunlight and this energy is further transferred to microscopic
animals as they feed on algae. These herbivores such as Snails are eaten by small
carnivorous fish. These small carnivorous fish are eaten by larger fishes. Therefore, here
producer is Algae, primary consumers are microscopic organisms such as Snails, Worms,
secondary consumers are small fishes while tertiary consumers are large carnivorous
fishes.
Functional aspects:-
1. Food chain :-
PREDATORY FOOD CHAIN
ALGAE----->SNAIL----->SMALL CARNIVOROUS FISHES--->LARGE
CARNIVOROUS FISHES
DETRITUS FOOD CHAIN
DETRITUS(DEAD ORGANIC MATTER)----> CATFISH
(After break down by bacterias, fungii)
2. Food web:-

4. 3. Ecological succession:-
EUTROPHICATION is an example i.e. When nutrients are washed fom surroundings such
as animal wastes, fertilisers in the water body, this leads to increase in growth of algae
which as a result decreases the level of CO2 and increases O2 in the water body. Since
every living organism is mortal and therfore when this algae dies it sinks down to the
bottom of the lake and since the amount of detritus is high therefore decomposition of this
by bacterias and fungii will lead to the excess of CO2 and O2 concentration will decrease
abruptly. This is due to the fact that these detrivores will breathe oxygen inside and
releasing CO2 while decomposing the organic matter. Therfore it will adversely affect the
lives of aquatic animals.
RIVERS AND STREAMS ECOSYSTEM
These are flowing water ecosystems in which all the living forms are specially adapted to different
rates of flow like Snails and other burrowing animals can easily withstand this flow while animals
such as water bettles can only live in slow moving water. The community of Flora and Fauna
depends on the clarity, flow and oxygen content as well as the nature of beds of the water body.
Structural aspects:-
1. Abiotic components:-Factors such as water flow, light, temperature, chemical composition
constitutes its abiotic components.
2. Biotic components :- Example, Algae grows in rivers and streams which derives energy
from sunlight and this energy is transferred to shrimp, wihch is eaten by a fish and this fish
is eaten by a large fish. Here, algae is producer, shrimp is primary consumer, fish is
secondary consumer and the large fish is secondary carnivore.
Functional aspects:-
1. Food chain :-ALGAE---->SHRIMP----->SMALL FISH----->LARGE FISH
2. Food web:-
3. Ecological succession:-
As deforestation occurs in the hill, the water in the rivers that once flowed throughout the
years bacomes seasonal. This causes floods during the rains and shortage of water followed
by the monsoon. The formation of dams drains the river which again leads to floods during
rainfall since the water body which could have stored that rainwater doesn't exist anymore
and those which were dependent on rivers for water supply, their lives also gets affected.

5. MARINE ECOSYSTEM
Oceans, seas and other saline water bodies constitues marine ecosystem. Producer in this
ecosystem varies from microscopic algaes to large seaweeds.
Structural aspects;-
1. Abiotic Component:- Sunlight, temperature, moisture, winds, wind currents, soil type, high
concentraion of salts of Na, K, Ca, Mg constitute the abiotic components of marine
ecosystem.
2. Biotic components:-
✔ Producer: Phytoplanktons, large seaweeds
✔ Primary consumer: Custaceans such as crabs
✔ Secondary consumer: Carnivorous fishes
Functional aspects:
1. Food chain:
Phytoplanktons---->custaceans---->fishes---->dolphins---->whales
2. Food web:
3. Ecological succession:-
Primary succession may take place following the eruption of volcanoes, as lava flows into
the ocean, new rock is formed which due to weather or natural forces breaks down such that
establishment of plants and lichens occur. These species help in further breaking down of
this mineral lavainto soil. When these species are dead, they decompose leading to soil
formation. This process is repeated multiple nmber of times for hundreds of years. At each
stage, species move into an area due to changes occuring. After a signification amount of
time this ecosystem may reach relatively stable state.

6. ECOLOGICAL PYRAMIDS FOR AQUATIC ECOSYSTEM
Ecological Pyramid :-
✔ Pyramid of number
In aquatic ecosystems autotrophs are present in large number per unit area but they support
a lesser number of herbivores and they in turn support lesser number of carnivores.
✔ Pyramid of biomass
In aquatic ecosystems pyramid of biomass is inverted since the food chain in water bodies
would start from phytoplanktons and will end at predatory fish which has the largest
biomass.
✔ Pyramid of energy
An energy pyramid represents the amount of energy at each trophic level and loss of energy
at each transfer to another trophic level. Hence the pyramid is always upward, with a large
energy base at the bottom.

7. THREATS TO AQUATIC ECOSYSTEM
1. POLLUTION:-
The deposition of cheimcal, industrial and solid wastes in the water bodies cause disturbance
in yhe ecosystem. The oxygen content gets reduced which will lead to death of aquatic
species.
If some fertilizers or animal wastes are introduced then it may lead to
EUTROPHICATION, affecting the lives of aquatic species.
2. INVASION:-
The intoduction of a new species in an ecosystem can sometimes lead to disturbances. This
can affect other species of plants or animals living in the ecosystem and can even lead to
extinction of the species from that ecosystem, affecting the entire ecosystem permanently.
3. OVERFISHING:-
Our food and energy requirements are met through fishes and therefore fishing is such a
common practice but overfishing causes a huge disturbance in the processes occuring in the
ecosystem. Like, oversfishing as a consequence will lead to an increament in the number of
species that belong to lower trophic level and decreament in number to those who are just
above to their trophic level(due to starvation) and this way the entire ecosystem suffers
imbalance and unstability.
4. CLIMATIC CONDITIONS:-
Less rainfall and acid rains can affect the ecosystems, ponds will be affected largely since
they are small water bodies and rainfall is the cause of their existence. On the other hand,
acid rains will also affect ponds ecosystem the most since they are small and a small change
will change the concentration to a greater extent.
5. HUMAN INTERFERENCE AND URBANISATION:-
These factors again affect the lives of the aquatic species.
6. FORMATION OF DAMS:-
The rivers, streams and other water bodies are drained so that dams can be built. This not
just causes the loss of habitat to many aquatic species but also leads to floods. And most
importantly, this will also affect lives of those which were dependent on the ecosystem for
the water supply.
7. DEFORESTATION:-
This affects the ecosystem as deforestation cause floods. It also causes soil erosion.
8. AGRICULTURALACTIVTIES:-
The formation of canals for irrigation purposes affect these ecosystems as the level of water
lowers down.
IMPORTANCE OF AQUATIC ECOSYSTEM
1. Ecosystems are extremely essential since all the processes occuring are interrelated to each
other and their existence, directly or indirectly, affects the existence of each and every living
organism.
2. Ecosystems support biodiversity and provides shelter to many species(aquatic).
3. They provide water supply for agricultural, industrial and domestic purposes.
4. This water can be treated and purified so that it can be used for many different purposes.
5. They are also used to produce hydropower, hydroelectricity and thermalelectricity.
6. They help in preventing floods.
7. They provide us food resources such as fishes.

8. 8. If during monsoons, waterlogging occurs then this water can be directed towards these
ecosystems.
9. Marine ecosystems are the major source of salt which is a necessity while cooking.
10. Natural ecosystems such as rivers and seas break down chemical and organic wastes created
by man.
MEASURES FOR CONSERVATION OF AQUATIC ECOSYSTEMS
1. Overstocking of fishes should be restricted. Fishing should be done sustainably.
2. No chemical or industrial wastes should be disposed of in the water bodies.
3. Human interfernce towards these ecosystems should be limited.
4. The pond or river ecosystem should not be drained off for urbanisation or for construction of
dams.
5. The way forests are being conserved through wildlife sanctuaries, similarly for aquatic
ecosystems as well these sanctuaries should exist.
6. No fertilizers or animal wastes should be disposed since it can lead to EUTROPHICATION.
7. For agricultural and irrigation purposes the water supply from these ecosystems should be
limited otherwise it will affect the lives of those aquatic species.
8. Spreading awareness regarding, “ Why these ecosystems are indispensible to us?”, “How
our lives are related to theirs?” etc.
CONCLUSION
While preparing this report, I got to learn a lot of things related to our environement and
ecosystems, that why and how they are so indispensible to us. The processes that occur around us
all the time in the environment which we are a part of , we really don't pay much attention to them.
But learning these things not only makes us understand the environment better but also lets us make
some fruitful changes so that our environment can get better and more sustainable. Out of all the
living oragnisms on the earth we are the only species which can make some difference and that will
happen only if we are well informed about everything. Our concern towards our environment can
make things better not just for us, but for the entire community of living species.
➢ I got to learn that how human interference to an ecosystem not just only affects its biotic
part but those tribal people as well who have lived there before the dams were built as they
are displaced to build large dams. These dams make rich people richer in the farmland and
supports people in large urban centres that use enormous quantities of water. The poor
tribal folk become even poorer as the natural resources they depend on are taken away as
their lands are submerged under the water of the dam.
➢ I also got to learn that in the coastal area the sea is shallow while further away, it is deep.
Both these are different ecosystems. The shallow areas near Kutch and around the
Andaman and Nicobar Islands are some of the most incredible coral reefs in the world.
Coral reefs are only second to tropical evergreen forests in their richness of species. Fish,
crustacea, starfish, jellyfish and the polyps that deposit the coral are a few of the thousands
of species that form this incredible world under the shallow sea.
➢ According to a survey conducted by the Assam Remote Sensing Application Center
(ARSAC), Guwahati, and the Space Research Center, Ahemadabad, it has been revealed
that 1367 out of 3513 wetlands(i.e. Around 40%) in Assam are under severe threat due to
INVASION of aquatic weeds and several developmental activities. Though wetlands of
Assam form the greatest potential source of income for the State in terms of fisheries and

9. tourism.
➢ Aquatic ecosystems, especially wetlands, need protection by including them in Sanctuaries
or National Parks in the same way in which we protect natural forests. These sanctuaries in
aquatic ecosystems protect a variety of forms of life as well as rare fish which are now
highly endangered such as the Mahseer.
REFERENCES:-
I. https://ugc.ac.in/oldpdf/modelcurriculum/env.pdf
II. https://www.iucnffsg.org/freshwater-fishes/major-t