Long-term and short term effects of elevated underwater sound on oyster toadfish (Opsanus tau)

Abstract

The effects of underwater sound on fishes are of increasing concern for managers, regulators, and researchers. While there has been work which demonstrated changes in behavior, these studies have generally evaluated of immediate or near-term responses. Understanding acute changes in behavior is necessary, but questions about long-term responses to underwater sound, including any habituation and the relative influence of environmental conditions versus anthropogenic sound must also be investigated. To further elucidate potential response to chronic underwater vessel generated sound, passive acoustic monitoring was used to measure the response of vocalizing oyster toadfish (Opsanus tau) to vessel sounds within the Chesapeake Bay. An automatic detector was configured which allowed for counting of vessel passages and toadfish vocalizations. The response of vocalizing toadfish individual vessel movement was then evaluated. Next the response of toadfish to elevated sound levels across a 30-day period was measured and compared to short-term response. In addition, the influence of environmental variables and contrasted effects of these on the effects of increased anthropogenic sound was investigated.