What is mutualism? Bottlenose dolphins and Brazilian fishermen demonstrate

Inputs by Maanya Jindal

It is often said that the dog is man’s best friend, but they are not the only animal that humanity has befriended. Throughout our evolutionary history, humans have cooperated with wild animals for the welfare of both species, a process known as mutualism. 

An interesting example of mutualism has been observed by scientists.

Image Credit: Oregon State University

Dr. Mauricio Cantor, a behavioral ecologist, has been studying the relationship between local fishermen and bottlenose dolphins and how they work together to catch mullet fish.

In a lagoon of the coastal town Laguna, in southern Brazil, fishermen wait every sunrise for the dolphins to approach the coast and dive- an indication that now is the time to cast their nets.

Cantor observed this unique behavior, and that it had been going on for centuries.

After combining a couple of tools – drones, underwater microphones and a sonar camera that uses sounds to generate images, much like an ultrasound for pregnancy tests, Cantor learned that the dolphins were driving schools of fish towards the coast and into the fishermen’s nets. When the dolphins did so, they were able to catch the fish that slipped out of the nets and actually eat more than they would have without the fishermen. 

Although rare, examples of mutualism like this one have been observed in other parts of the world like Myanmar and India.