Dolphins are relevant to humans because we are still looking and researching our origins in the animal kingdom. There are similarities between dolphins and humans that do not exist with apes.
Also, dolphins act as ecological indicators which mean that they are bio-indicators on the condition of the marine environment and thanks to their behavior and health, we can detect and prevent some problems in the ocean biome, such as pollution or diseases that are expanding to populations of fish.
Likewise, they are predatory animals of various types of fish and marine animals, which contributes to the optimal function of the food chain where they inhabit. All these reasons directly affect humans, since a healthy ocean is synonymous with life on the planet.