Here's why:
* Nekton are animals that actively swim and move independently in the water column. They are not dependent on currents or the ocean floor for movement. Dolphins are strong swimmers with powerful tails and fins, allowing them to travel long distances.
* Benthos are organisms that live on or in the ocean floor. This includes creatures like crabs, starfish, sea anemones, and certain types of fish. Dolphins, being active swimmers, do not fit this description.