Off the Scottish coastline, farmers cultivate salmon in large ocean pens. These netted areas teeming with fish are within sight, sound, and smell of wild\u2014and hungry\u2014harbor seals. From a seal\u2019s perspective, salmon farms are likely idyllic places: captive buffets just begging to be burgled. But in truth, salmon farms are not easy pickings: in many places, including Scotland, thieving seals are often punished with a bullet to the head. Dead seals don\u2019t steal salmon.<\/p>\n
Wherever human herds meet wild carnivores, conflict arises. And in these battles of life versus livelihood, it is almost always the predator that loses. Thomas G\u00f6tz, a marine mammalogist at the University of St Andrews, thinks there\u2019s a better way to resolve these conflicts: loud noises.<\/p>\n
Using blaring horns and sirens to spook predators isn\u2019t an entirely new idea. But typical devices\u2014known as \u201cacoustic deterrents\u201d\u2014have only limited utility: most animals eventually habituate to the sounds. In some cases, acoustic deterrents actually cause problems of their own, contributing yet more noise pollution to an already cacophonous soundscape. Even worse, most acoustic deterrents aren\u2019t specific to the problem species, and wind up driving away non-target animals, too.<\/p>\n
G\u00f6tz thinks that acoustic deterrents can benefit from a more targeted approach.<\/p>\n
In a test, G\u00f6tz wanted to see if he could use short, unpredictable, brief, and isolated bursts of specific sounds to target only seals\u2014like a dog whistle in reverse. The idea, he says, is to activate a seal\u2019s startle reflex. It wouldn\u2019t be just better for the seals, he suggests, but by reducing the overall amount of artificial sound it would be better for the entire marine community.<\/p>\n