Researchers from Johns Hopkins University have found a possible reason why fish prefer to move in schools rather than alone. According to scientists, this information will help create quieter submarines.

As a rule, fish of the same species, most of which are at the same stage of the life cycle, gather in a school. About a quarter of all species known to science spend their entire lives in such herds. These are usually small pelagic fish such as herring and anchovies. About half of species live in herds for only part of their lives, usually until puberty.

Schooling is good for Pisces for many reasons. First of all, it is protection against predators. When there are many individuals, they are more likely to recognize a threat. In addition, since there is a group of relatives, the probability of being caught is less. Schooling helps fish migrate more effectively, searching for food or mating partners.

Scientists from Johns Hopkins University (USA) have found a new possible reason why many fish move more efficiently in schools than alone. The researchers’ results are presented in the journal Bioinspiration and Biomimetics. They created a 3D model of mackerel movement to simulate different numbers of swimming fish. The scientists also varied the structure of the school, how close the mackerel swam together, and the degree to which their movements were synchronized.

The researchers found that a flock of fish that moved their caudal fins asynchronously was extremely effective at reducing noise: A group of seven fish was no louder than a single individual. Thus, the voices of each “overwhelmed” each other. If the fish simultaneously wagged their tails, the sounds, on the contrary, were summarized. As the fish joined the school, the noise decreased. Therefore, for predators such as sharks, these sounds may be a signal that they are dealing with a single individual rather than a group.

“Sound is a wave. If two waves are in phase, they can merge, or if their phases are different, they can neutralize each other. “Of course, we are talking about very weak sounds that the human ear can barely perceive,” said Rajat Mittal, one of the authors of the study.

In addition to reducing sound, the asynchronous movement of the caudal fins also creates interaction between Cosmos and the water flow between the fish, allowing the fish to swim faster while expending less energy. These findings, the scientists suggest, could be useful in the design and operation of nature-inspired vehicles.