Joseph J. Luczkovich - luczkovichj@mail.ecu.edu
Mark W. Sprague and Stephen Johnson
Department of Biology and Institute for Coastal and Marine Resources
East Carolina University
Greenville, NC 27858
Popular version of paper 4pAO5
Presented Thursday afternoon,
June 25, 1998
ICA/ASA '98, Seattle, WA
The weakfish (Cynoscion regalis) and red drum (Sciaenops ocellatus) are highly desired and economically valuable fishes found in Atlantic and Gulf of Mexico coastal waters, including the Pamlico Sound in North Carolina. In recent years, declining stocks of these species has prompted investigations of their numbers and spawning areas. Like all members of the drum and croaker family (Family Sciaenidae), both of these fishes produce species-specific sounds during courtship, so it is possible to make recordings of their underwater signaling both in the field and in captivity. The acoustical spectrographs of their unique "drumming" can be used to identify and locate weakfish and red drum during their reproductive phases. The "purring" sounds of weakfish (audio sample #1) was recorded in conjunction with the presence of its floating eggs from May to July near Ocracoke and Hatteras Islands (see map #1). The "knocking" sounds of the red drum, along with counts of their eggs, were recorded in September at sites distant from the inlet, on the western side of the Pamlico Sound (Audio sample #2 and map #2, respectively). These economical, reliable and time saving passive acoustic surveys may be independently used to map the spawning areas of sound-producing fishes, enabling fishery managers to help protect critical stocks and habitats that have been declining in recent years.
Visit our group's website for more information and more sounds.