James Locascio, Ph.D., of Mote Marine Laboratory and the SCCF Marine Lab recently deployed two passive acoustic recorders at SCCF’s RECON (River, Estuary and Coastal Observing Network) stations at McIntyre Creek and Shell Point. These systems record ambient sounds across a broad frequency range at programmed time intervals. Sounds sources include fishes, marine mammals, boat traffic, atmospheric conditions, and sea state. Biological sounds have specific behavioral contexts associated with them, which may be reflective of ecosystem health and function and therefore may also be sensitive to disturbances or shifts in the ecosystem over different time scales.

The dominant sound sources in Charlotte Harbor are fishes, which produce sound in association with courtship and spawning. Acoustic recordings can document the timing and location where fish reproduction occurs. Several species of sciaenids (such as drums and seatrout) produce chorus events which begin near nightfall and continue for several hours each night from the spring through fall spawning season, as well as the winter period for black drum. Dolphins and manatees also produce sounds in social contexts and their presence can be documented when vocalizing within range of the recorders.

Locascio is Mote Marine Laboratory & Aquarium’s program manager for fisheries habitat ecology and acoustics. “The addition of these first two acoustic recorders on RECON sites is an exciting collaboration because it allows us to collect biological data on the same time periods in which we collected physical and chemical water quality data,” he says. “This will enable us to explain how changes in environmental conditions affect bioacoustic data during daily and seasonal periods, as well as disturbances such as red tide events and hurricanes, and the effects of river flow and water management of the Caloosahatchee system on the habitat of lower Charlotte Harbor estuary.”