Evaluating an underwater passive acoustic network in Everglades National Park to understand the effects of upstream ecological restoration
In August 2014, a suite of passive acoustic sensors were deployed in Florida Bay, a 2,200 km2 tropical estuary consisting of multiple connected shallow basins. The object of this pilot study was to evaluate if an acoustic-based biological monitoring program could be used to understand the effects of upstream restoration efforts in the Greater Everglades Ecosystem and Everglades National Park. The combination of an extensive physical oceanographic dataset paired with long-term passive acoustic monitoring could provide important insight on how the ecosystem is responding to restoration efforts. Three different acoustic monitoring systems were developed and deployed at six existing NOAA buoy stations in Florida Bay. Acoustic data at all sites were analysed for the presence of soniferous fish and snapping shrimp activity, as well as acoustic signatures and temporal patterns associated with the physical environment and anthropogenic activity.
All acoustic monitoring systems collected high quality acoustic data and we recommend two of the systems for longer term deployment using power supply at a NOAA station. The third system is ideal for recording at locations without external power supply and would have a shorter recording duration. Our analysis identified at least two species of fish present at multiple sites and site-specific patterns in bioacoustic activity. These results provide possible metrics of biological activity to compare with measures of the physical environment (e.g. salinity, temperature). Future efforts will focus on optimizing spatial coverage and temporal sampling, as well as efficient data management for a suite of long term acoustic monitoring sites in Florida Bay.