What is the role of zooplankton?

• A. Base of the food web
• B. Food for fish, whales
• C. Oxygen source
• D. Primary production and oxygen source

Answer: (B)

Zooplankton are the animal link in the plankton community. They feed on phytoplankton and then provide a crucial food source for larger animals like fish and whales. This transfer of energy up the food chain is essential for supporting marine ecosystems and fisheries. They don’t produce oxygen themselves—that’s the job of phytoplankton through photosynthesis—and they’re not the primary producers. So the best description is that zooplankton are food for fish and whales.