Impact of Acoustical Human Made Stressors on the Spawning of Red Drum

Impact of Acoustical Human Made Stressors on the Spawning of Red Drum


Click here for the full Journal of Fish Biology article: Long-term monitoring of captive red drum Sciaenops ocellatus reveals that calling incidence and structure correlate with egg deposition.

USCB-student-Bradshaw-McKinneyRed-drum-larvaeChris-Kehrer-left-and-Micahel-Powell

Red drum are one of the most important inshore recreational fisheries in the state of South Carolina. Where do they spawn? That's a tricky question to answer for marine biologists.

One of the very fascinating aspects of red drum reproduction is that males make a drumming sound using their swimbladder and sonic muscle to attract females to a spawning location. Dr. Montie, Chris Kehrer, and colleagues at the SCDNR used acoustic recorders, placed them in SCDNR tanks that contained male and female red drum, and monitored spawning.
They showed that more calling, longer calls, and higher sound pressure levels were associated with spawns that were more productive. In fact, they showed that when male red drum calls were longer, more eggs were released by females. This work is important because it indicates that acoustic metrics can provide quantitative information on spawning in the wild.

Currently, we have no idea where red drum spawn in the inshore and offshore waters of South Carolina. However, we can use passive acoustics to listen to the estuarine soundscape and find these spawning aggregations, which will help us better understand dispersal of larvae, recruitment, and the replenishment of the adult population.

By locating these aggregations and studying their behavior, we can get a better handle how human-made stressors like climate change, chemical pollutants, and noise pollution may impact their reproduction and survival.

A USC ASPIRE 1 grant supported this research and provided Chris Kehrer (a past USCB graduate) an opportunity to perform research in the Montie Marine Sensory and Neurobiology Lab at USCB. Chris Kehrer was a coauthor of this manuscript and was able to land a job in marine biology and is now a naturalist at the Port Royal Sound Foundation. The title of the paper was "Long-term monitoring of captive red drum Sciaenops ocellatus reveals that calling incidence and structure correlate with egg deposition". This work was performed in collaboration with Justin Yost, Karl Brenkert, Tim O'Donnell, and Dr. Mike Denson at the South Carolina Department of Natural Resources.

*Picture of the student with the redrum is current student Bradshaw McKinney. Chris Kehrer (left) and Michael Powell are former students doing research. The other picture if of red drum larvae.