Red grouper produce sounds throughout the day and night, mostly at sunrise and sunset. Red grouper produce two types of low-frequency (with a peak near 180 Hz), pulse vocalizations. The first consists of 1 to 4 brief (0.15 second) pulses immediately followed by a 0.5-2 second short call, or growl. Produced less frequently, the second vocalization is the short call followed by a burst of 10 to 50 pulses. Behaviors associated with red grouper sound production include males patrolling, male and female fish swimming together, and/or direct physical contact between male and female fish while rapidly swimming. These observations, in addition to red grouper producing sound during a known peak-spawning month (May), indicate that sound production in red grouper is likely related to spawning activity.Understanding red grouper spawning activity and defining spawning areas is key to fisheries management of the species. Red grouper are a commercial important fishery. Since they are long-lived and grow slowly, they are vulnerable to fishing pressure. Fisheries managers are looking to designate marine reserves to protect red grouper stocks. Passive acoustics can be used to monitor red grouper behavior, map their and define critical habitat. Passive acoustic platforms, such as underwater gliders, have been used to detect and map red grouper sound production in the Gulf of Mexico.
- Nelson, M.D., Koenig,C.C., Coleman, F.C. and Mann, D.A. 2011, "Sound production of red grouper Epinephelus morio on the West Florida Shelf." Aquatic Biology. 12, 97-108.
- Gleason, A.C.G., Eklund, A.-M., Reid, P.R., and Koch, V., "Acoustic signatures of the seafloor: tools for predicting grouper habitat." Professional Paper NMFS 5.
- "Florida Fish and Wildlife Commission, Red Grouper." (Link)
- "Florida Museum of Natural History, Red Grouper." (Link)
- "NOAA Fish Watch, Red Grouper." (Link)