Question

Given below are two statements :
Statement (I) : Otter boards in gill nets are used for horizontal opening.
Statement (II) : Floats and sinkers are used for vertical opening.
In light of the above statements, choose the most appropriate answer from the options given below:

• A. Both Statement (I) and Statement (II) are true.
• B. Both Statement (I) and Statement (II) are false.
• C. Statement (I) is true but Statement (II) is false.
• D. Statement (I) is false but Statement (II) is true.

Hint:

Otter boards are only used in trawling (active towing) to open the net horizontally. Floats and sinkers are universal components used across many gear types to keep nets open vertically.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Active and passive fishing gears rely on different mechanisms to keep the net open while in the water, ensuring maximum fish capture.
Detailed Explanation:
- Analysis of Statement (I): Otter boards (or trawl doors) are hydrofoil-like structures used exclusively in trawl nets (active towing gear).
When the vessel moves, water pressure acts on the otter boards, pushing them outward and keeping the mouth of the trawl net open horizontally.
Gill nets are passive drift or set nets that do not use otter boards.
Therefore, Statement (I) is incorrect.
- Analysis of Statement (II): Floats are attached along the headrope (top line) of a net, providing upward buoyancy.
Sinkers (weights) are attached along the footrope (bottom line), providing downward pull.
Together, the buoyant force of the floats and the sinking force of the sinkers pull the net open vertically in the water column.
This is a standard method used in both gill nets and trawl nets.
Therefore, Statement (II) is correct.

Step 2: Final Answer:
Statement (I) is false but Statement (II) is true, corresponding to option (4).