Dolphins are a true angler’s friends! Beloved mammals herd schools of fish into trawler crew nets so they can intercept the stragglers left behind, research shows
Dolphins have long been observed helping humans catch fish. Now scientists think they know why — the dolphins themselves are catching more fish while staying safe.
The researchers examined drone footage, sonar and acoustic footage from the murky waters off Laguna, Brazil, where massive pods of dolphins head for waiting fishermen.
The dolphins dive to signal the fishermen when to cast their nets and then help themselves to the fish, separating it from the main school.
dr Mauricio Cantor of Oregon State University, who led the study, which is published in the Proceedings of the National Academy of Sciences, said: “Dolphins and humans have the same goal – to catch fish. They can do it alone, but have learned that they do better as a team.”
Dolphins have long been observed helping humans catch fish by diving as a signal to cast their nets
Fishermen were 17 times more likely to catch fish, while cooperative dolphins were 13 percent less likely to die.
Cooperative dolphins off the coast of Brazil signal fishermen who can’t see fish under the murky water when they’ve landed a big catch.
They do this by suddenly diving under water, whereupon the fishermen immediately cast their nets.
Researchers who observed more than 2,000 interactions found that the tactic worked well, as the dolphins dived and the fishermen responded quickly and in a timely manner about half the times.
Clear evidence that dolphins benefited came from sonar evidence that they stole fish from the nets.
![The researchers examined drone footage, sonar and acoustic footage from the murky waters off Laguna, Brazil, where massive pods of dolphins head for waiting fishermen. [File image]](https://www.spamchronicles.com/wp-content/uploads/2023/01/1675131104_270_Dolphins-are-a-true-anglers-friends-Beloved-mammals-drive-schools.jpg "Dolphins are a true angler's friends! Beloved mammals drive schools of fish into the nets of the trawler crew 4")
The researchers examined drone footage, sonar and acoustic footage from the murky waters off Laguna, Brazil, where massive pods of dolphins head for waiting fishermen. [File image]
Almost two-thirds of the fishermen surveyed said they felt the creatures run away with some of their catch.
After herding the fish, which were mostly mullets, and casting out their nets in response, the dolphins spent more time producing rapid clicks that sounded so close together, as if they were humming.
Unlike normal navigation clicks, these quick clicks indicate that the creatures are heading for prey.
Dolphins also spent longer underwater after working with fishermen.
Both behaviors suggest that working with the fishermen gave the creatures more fish than usual.
Fishermen certainly benefited as they are 17 times more likely to catch fish and nearly four times as many mullets when teaming up with dolphins.
When the dolphins cooperated with the fishermen, they were 13 percent less likely to die than non-cooperative dolphins.
This is probably because cooperative animals tend to stay in a smaller area and are therefore less likely to end up as ‘bycatch’ in other illegal fishermen’s nets.
Dolphins have also been found to work with fishermen in countries like Myanmar and India.
However, the researchers warn that the fascinating behavior could be lost within 40 to 60 years.
That’s because fish numbers are declining and the pressure on traditional fishermen could cause many to give up, losing decades of knowledge about working with dolphins.
The 15-year study is published in the journal Proceedings of the National Academy of Sciences.