Question

How many billion tons productivity of oceans?

• A. 55
• B. 70
• C. 155
• D. 170

Hint:

Despite low productivity per unit area, oceans contribute significantly due to their vast expanse — about 55 billion tons.

Answer 1

The Correct Option is A

The ocean’s net primary productivity is approximately 55 billion tons (gigatons) of organic matter annually.
Though oceans cover ~70% of Earth's surface, their productivity per unit area is less than terrestrial ecosystems, but total contribution is large due to vast area.