In Laguna, Brazil, a unique human-dolphin relationship has developed, where bottlenose dolphins assist local fishermen in catching mullet fish. The dolphins herd the fish towards the fishermen and then splash the water to signal that the haul is ready.

This behavior has been going on for generations and has been the subject of research for the past two years.

Researchers have found that out of a population of 150 dolphins, 50 will help the fishermen, acting as sheepdogs to herd the mullets towards the waiting boats. The dolphins slap their heads or tails against the water to signal that the fish are ready to be caught.

The researchers noted that the 50 helpers are the most social dolphins in the pack and are tightly associated with each other in the waves.

The researchers are still unsure why the dolphins help the fishermen, as they do not receive any food in return. Some theories suggest that the dolphins may be forming a new human-dolphin alliance, while others speculate that they may simply be lending a helping fin to those in need.

This unique behavior has been detailed in a research paper titled “The structure of a bottlenose dolphin society is coupled to a unique foraging cooperation with artisanal fishermen.” The paper reports that the dolphins helping the fishermen are only found in specific spots of the area, and only about a third of the population behaves in this way.

This behavior has caught the attention of the scientific community and the public alike, raising questions about the complex relationship between humans and animals in the wild. As research continues, we may learn more about the motivations behind this remarkable phenomenon.