EDITORS CHOICE IN ZOOLOGYThe paperS.S. Urmy, K.J. Benoit-Bird, “Fear dynamically structures the oceans pelagic zone,” Curr Biol, doi:10.1016/ j.cub.2021.09.003, 2021. While sorting through information from an echosounder released off the coast of central California in 2010, masters trainee Sam Urmy observed what looked like acoustic disturbance. Most of the information showed the movements of marine animals swimming above the gadget, periodically there d be a spike that “looked very comparable to what you d get if there was another ship nearby running the same kind of echogram,” he states. He understood the spikes were due to dolphins, which were using echolocation and sending smaller sized animals scattering.The observation got him considering predator avoidance as a driver of animal movements, and he just recently returned to the idea as a postdoc working with Kelly Benoit-Bird at the Monterey Bay Aquarium Research Institute. Utilizing a fresh, year-long echosounder data set, plus statistical modeling, the pair concluded that dolphins and other predators cause fish to flee– typically, to deeper waters– and that fish schools set off similar responses in zooplankton, producing a constant ballet of vertical movements as everyone tries to prevent being consumed. Together with better-studied factors such as day-night cycles, this fear habits most likely motivates animal motion all over the oceans, recommends Urmy, now at the National Oceanic and Atmospheric Administration (NOAA). Deepwater Echo Integrating Marine Observatory System (DEIMOS), an upward looking echo sounder plan, at the Monterey Accelerated Research System (MARS) ocean observatory, located at around 900 meters deep in Monterey Bay. © 2009 MBARI” Its very intriguing to get such a long, comprehensive view of these motions of smaller animals in the pelagic zone,” says Michael Heithaus, a marine ecologist at Florida International University who was not associated with the work. While the findings arent surprising– there are numerous examples of fear driving animal habits– its outstanding to show it throughout the food web like this, he notes, adding that it will be essential to identify how short-term motions translate to longer-term trends in survival and population sizes. Plus, he adds, “I d enjoy to see how this plays out in different locations.”
