Question

How does water temperature impact fisheries?

• A. Higher temperatures reduce fish metabolism
• B. Lower temperatures decrease dissolved oxygen levels
• C. Warmer water enhances fish growth and reproduction
• D. Temperature has no effect on fish behaviour

Hint:

In ectotherms (cold-blooded animals), higher temperatures within optimal limits speed up chemical and metabolic reactions, directly promoting faster growth.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Water temperature is a key physical factor that governs the physiological and ecological processes of aquatic ectotherms, such as fish.

Step 2: Detailed Explanation:
Fish bodies remain in thermal equilibrium with their aquatic environment.
Within a species' optimal temperature range, warmer water accelerates metabolic rates and enzymatic processes, which can increase food intake, growth, and reproduction.
Conversely, colder temperatures slow down metabolic activity.
While high temperatures also reduce the solubility of dissolved oxygen, within non-lethal, optimal ranges, warmer water is associated with enhanced developmental rates and reproductive activity.
Temperature also acts as a environmental cue, triggering migration, spawning, and feeding behaviors.

Step 3: Final Answer:
Therefore, within optimal biological ranges, warmer water temperatures enhance metabolic rates, accelerating growth and reproduction in fish.