What is Bycatch?

S4-SA4-0479

Grade Level:

Class 8

Space Technology, EVs, Climate Change, Biotechnology, HealthTech, Robotics, Chemistry, Physics

Definition

What is it?

Bycatch refers to marine animals that are caught unintentionally by fishermen while they are trying to catch a different type of fish or seafood. These animals are often thrown back into the ocean, usually dead or dying, because they are not the target species.

Simple Example

Quick Example

Imagine you are trying to catch only specific types of ripe mangoes from a tree. But while shaking the branch, some small, unripe mangoes and a few leaves also fall down. These unwanted mangoes and leaves are like 'bycatch' – they weren't what you aimed for.

Worked Example

Step-by-Step

Let's say a fishing boat goes out to catch 'Rohu' fish.

Step 1: The boat casts its net into the ocean.
---Step 2: When the net is pulled up, it contains 100 Rohu fish (the target).
---Step 3: But the net also contains 20 small crabs, 5 starfish, and 3 sea turtles.
---Step 4: The crabs, starfish, and sea turtles were not intended to be caught; they are the 'bycatch'.
---Step 5: The fishermen keep the 100 Rohu fish and discard the 28 bycatch animals.
---Answer: The 20 crabs, 5 starfish, and 3 sea turtles represent the bycatch in this fishing trip.

Why It Matters

Understanding bycatch is crucial for environmental science and sustainable development, helping us protect marine life and ensure oceans remain healthy. It's important for careers in marine biology, environmental policy, and even in developing smart fishing technologies like those used in robotics for selective harvesting.

Common Mistakes

MISTAKE: Thinking bycatch only includes small, non-edible fish. | CORRECTION: Bycatch can include any marine animal caught unintentionally, regardless of size or whether it's edible, including large animals like sharks, dolphins, and sea turtles.

MISTAKE: Believing bycatch is always released alive and healthy. | CORRECTION: Sadly, many bycatch animals are injured or dead by the time they are brought onto the boat, and even if released, their chances of survival are often low.

MISTAKE: Confusing bycatch with illegal fishing. | CORRECTION: Bycatch is an accidental outcome of legal fishing methods, while illegal fishing refers to fishing without permission or violating fishing laws.

Practice Questions

Try It Yourself

QUESTION: A fishing boat aims to catch 50 kg of prawns. It ends up catching 45 kg of prawns and 5 kg of small, unwanted fish. What is the bycatch in this scenario? | ANSWER: 5 kg of small, unwanted fish.

QUESTION: A trawler net catches 150 tuna, which are its target. It also catches 10 sharks, 2 dolphins, and 20 sea snakes. How many individual animals are considered bycatch? | ANSWER: 32 individual animals (10 sharks + 2 dolphins + 20 sea snakes).

QUESTION: If a country sets a rule that bycatch should not exceed 10% of the total catch by weight. A fishing vessel catches 200 kg of target fish and 25 kg of bycatch. Is this vessel following the rule? Explain. | ANSWER: No. The total catch is 200 kg + 25 kg = 225 kg. 10% of 225 kg is 22.5 kg. Since 25 kg of bycatch is more than 22.5 kg, the vessel is not following the rule.

MCQ

Quick Quiz

Which of the following best describes bycatch?

Fish that are caught for food

Animals caught accidentally while fishing for something else

Fish that are too small to be sold

Animals caught using illegal methods

The Correct Answer Is:

Bycatch specifically refers to marine animals caught unintentionally, not necessarily for food or due to illegal methods. Option B correctly identifies the accidental nature of bycatch.

Real World Connection

In the Real World

In India, coastal communities and fishing villages often face the challenge of bycatch. Organizations like the Central Marine Fisheries Research Institute (CMFRI) are working with fishermen to design better fishing nets and techniques, like using Turtle Excluder Devices (TEDs) in nets, to reduce the accidental capture of sea turtles and other non-target species.

Key Vocabulary

Key Terms

TARGET SPECIES: The specific fish or marine animal that fishermen intend to catch. | TRAWLER NET: A large, cone-shaped net dragged along the seabed or in mid-water to catch fish. | MARINE LIFE: All living organisms that live in the ocean. | SUSTAINABLE FISHING: Fishing practices that ensure fish populations and marine ecosystems remain healthy for future generations.

What's Next

What to Learn Next

Now that you understand bycatch, you can explore 'Sustainable Fishing Practices'. Learning about these practices will show you how scientists and communities are working to reduce bycatch and protect our precious marine environment.