Meeting Abstract
Acoustic communication is critical for reproductive success in the Oyster Toadfish, Opsanus tau. Passive acoustics allows for non-invasive monitoring of fish vocalizations and previous studies have determined the seasonality of toadfish calls in Eel Pond in Woods Hole, MA using a single hydrophone. Over the last century, human activities have increasingly added artificial sounds to the aquatic environment. The purposes of this study were to determine the number and location of vocalizing toadfish in Eel Pond using a multiple hydrophone array and to monitor how different abiotic and biotic factors impact toadfish calls. Numerous motorized watercraft armored in Eel Pond, including the RV Gemma, which presents a unique opportunity to monitor toadfish vocalizations in response to anthropogenic sound. A four-hydrophone linear array was deployed to record underwater sound. The number of calls, amplitude, time interval and location of fish recorded from the hydrophones were analyzed. Six different vocalizing toadfish were located and monitored over the course of the breeding season. Anthropogenic sound produced by the RV Gemma and heavy rain events depressed vocalization rates in toadfish. Boatwhistle playbacks using a previously recorded toadfish call increased the amplitude and number of toadfish calls during the peak mating season. The multiple hydrophone array allowed for individual toadfish locations to be determined and monitored and provided data that shows toadfish vocalization rates can be influenced by anthropogenic, environmental and conspecific sounds.
