Spatial and temporal patterns of toadfish and black drum chorusing activity in the South Atlantic Bight

Abstract

Many fish species produce sounds as a part of their reproductive behavior. Using passive acoustic recording approaches, these sounds can be used to document temporal and spatial patterns of reproductive activity of fish populations. We conducted an 11-month passive acoustic survey at three different locations off the coasts of Georgia (40 km north of Grays Reef National Marine Sanctuary) and North Carolina (Onslow Bay) to understand the spawning phenology of two species of acoustically active fishes: black drum (Pogonias cromis) and toadfish (Opsanus sp.). Due to the depth of the recording locations, we could not confirm whether the toadfish calls were produced by O. tau, or another Opsanus species. Both taxa have readily identifiable, distinct sounds. Chorusing sounds from both species were detected at all three Georgia sites and at two of the three North Carolina locations; chorusing duration of both species was greater in Georgia. The onset and duration of chorusing activity for both species was correlated with water temperature. The abundance of calls of these two species from field recordings further demonstrates the value of long-term passive acoustic surveys for understanding the reproductive seasonality of acoustically active fish species.