How open ocean animals rely on groups to survive

Offshore waters present severe daily challenges for marine wildlife, characterized by scarce nourishment, abundant predators, and an absence of physical hiding spots. According to a recently published scientific review, these demanding conditions have driven diverse open-sea organisms, ranging from microscopic plankton to massive whales, to evolve coordinated grouping habits to stay alive.

The analysis was conducted by Kelly Benoit-Bird, a senior researcher based at the Monterey Bay Aquarium's research institute, MBARI, alongside William Oestreich, who heads a collective ecology laboratory at Zurich University after completing postdoctoral training supported by the U.S. National Science Foundation. Their collaborative paper appeared in the journal Philosophical Transactions B.

The authors examined several common social behaviors, such as traveling together in schools, synchronized vertical journeys between depth zones, and cooperative feeding tactics. Across the pelagic realm, which extends from sunlit surface layers down into the dim twilight ocean, creatures cannot seek shelter behind rocks or vegetation to evade hungry hunters.

To investigate these underwater interactions, Benoit-Bird directs an acoustic ecology team that utilizes sophisticated sound-based instruments. These advanced tools enable scientists to observe how marine animals locate sustenance while simultaneously evading pursuers, shedding valuable light on the dynamics of predator-prey encounters in vast water columns.

The researchers determined that three primary forces shape these communal habits: finding scarce nourishment, escaping danger, and coping with continuous water currents. These physical and biological pressures have repeatedly driven both vertebrate and invertebrate creatures throughout multiple ocean depths to develop synchronized group routines.

By evaluating wildlife activity across Earth's most expansive living environment, the authors explained that oceanic observations provide crucial clarity regarding why communal life evolved and how coordinated behaviors continue to support marine survival.