Anthropogenic sounds induce escape behaviour in southern stingrays Hypanus americanus

Abstract

Elasmobranchs are an important component of the marine ecosystem that face obvious anthropogenic threats through habitat degradation and overfishing, but the impact of anthropogenic sounds on these animals is less obvious and remains unclear. Using a Y-maze behavioural set-up with sound presentation on one side of the pen, we exposed southern stingrays Hypanus americanus to 4 types of anthropogenic sounds: 2-stroke boat, 4-stroke boat, cruise ship and airplane. While stingrays did not have a side preference, they did exhibit an increase in escape behaviours during all sound treatments. To our knowledge, this is the first study to examine the impacts of airplane sound on any aquatic animal, and we found that stingrays exhibited escape responses most often to airplane sounds. We demonstrate that anthropogenic sounds affect the behavioural response of stingrays and further state that more efforts are needed in determining the behavioural or physiological impacts of anthropogenic sounds on elasmobranchs.