Which of the following is the best example of a food chain in a marine ecosystem?A. Orca > seals > algae > salmon B. Phytoplankton > mussels > otters > tuna > octopus C. Phytoplankton > krill > herring > mackerel > shark

The best example of a food chain in a marine ecosystem among the options provided is: C. Phytoplankton > krill > herring > mackerel > shark

Explanation:

• A food chain represents a linear sequence of organisms where each organism serves as a source of food for the next in the chain.
• In the marine ecosystem, phytoplankton (microscopic algae) are primary producers that form the base of the food chain by converting sunlight into energy through photosynthesis.
• Krill, small shrimp-like creatures, often feed on phytoplankton, serving as primary consumers.
• Herring, a small fish, might consume krill and act as secondary consumers.
• Mackerel, a larger fish, can prey on herring, occupying a higher trophic level as tertiary consumers.
• Finally, the shark, being a top predator, may consume mackerel, representing the apex predator in this food chain.
• Option C represents a clear linear sequence of organisms in a food chain in a marine ecosystem, starting from primary producers (phytoplankton) to the top predator (shark).