Page 171 - Innovator's Science-8

Let's understand this with an example:
Plants die
• Suppose a pond becomes polluted.
• Because of the pollution, many plants in the
pond die. Less oxygen

• With fewer plants, there is less oxygen in the
water.
Fish die
• This causes many fish to die, since they rely on

that oxygen.
• With fewer fish to feed on them, the number More insects
of insects increases.
• These insects can spread to nearby farms and
Plants get
damage crops. damaged
• To protect crops, farmers start using more by pests

pesticides, which harms the environment even One change leads to another
more.
So, one change-pollution-can set off many negative effects, not just in the

pond but also in the surrounding areas.
What is the result of our interfere with nature?

Activity-9 Aim: to know about Indian bullfrog.
India used to export large quan es of frog legs in the 1980s. This was from the
Experiential Learning
Indian bullfrog (Hoplobatrachus gerinus)
Frogs are natural insect-eaters, so they help control pest
popula ons. But when too many frogs were captured for
export, their numbers declined. As a result, insect pests
increased in the fields. Farmers had to use more chemical
pes cides to control these pests. These pes cides harmed
the soil, water, environment, and even human health. Indian bullfrog
To stop this environmental damage, the Government of India banned the export of
frog legs.

An ecosystem stays healthy when all the organisms and their surroundings
are in balance. But this balance is not permanent – it can be easily disrupted

by natural events or human activities. Even a small change can cause big
impacts. That’s why it is important to protect every part of nature and le
ecosystems work in harmony.

HOW DO INTERACTIONS HELP KEEP ECOSYSTEMS IN BALANCE?

In nature, organisms do more than just eat or get eaten. They also interact
with each other in other important ways that help maintain the balance of

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Science-8