In addition to helping to entertain humans in aquatic zoos and on television, dolphins provide a number of services to humans. The United States and Russian militaries have trained dolphins to locate mines and save divers, while fishermen have trained dolphins to help increase their catch. Additionally, dolphins have been credited with rescuing many people from drowning and sharks.
Some of the most shocking instances of dolphins helping people involved dolphins that had not received any training. This is often the case with dolphins that save stranded swimmers or people who were threatened by sharks. According to Discovery News, some fishermen have been surprised by dolphins that began helping them. In these cases, the dolphins corralled the fish and then alerted the fisherman to cast his net through gestures and vocalizations. The dolphins appeared to tell the fishermen where to place their nets. Dolphins only rarely engage in these behaviors, and most of those that do are exceptionally social individuals.
Dolphins are very intelligent animals that respond well to human training. Skilled trainers can teach dolphins to perform a wide variety of tasks, from simple tricks such as flips and twists to finding and retrieving objects hiding in a pool.