Tracking Fish and Invertebrates with Acoustic Telemetry

Successful management of aquatic animal populations requires comprehensive studies at both population and individual scales. Population-level studies are necessary to obtain data related to the life histories of the animals, such as lengths, weights, ages, reproductive strategies, and diet. Individual animals caught at a certain place and time provide valuable data "snapshots" that can be averaged and applied to the rest of the population. Because the data are collected at discrete points in time and space, further information is often needed regarding individual movements over extended periods. By focusing on individuals, biologists are able to investigate behaviors such as home range and residency patterns, site fidelity (returning to a specific location), movement, migration, and habitat use.

Technological developments over the past two decades have brought acoustic telemetry into mainstream research, enabling biologists to monitor animals at the individual level. Telemetry studies involve tagging an animal either internally or externally with uniquely coded tags that transmit data ultrasonically. Tagged animals are monitored with handheld receivers for short periods of time or by moored receivers over extended periods of time and space.

Biologists at the FWC's Fish and Wildlife Research Institute (FWRI) use acoustic telemetry in both saltwater and freshwater environments to study an assortment of species, from goliath grouper on deep offshore wrecks to largemouth bass in shallow streams and rivers. These acoustic studies are specifically tailored to account for the life histories and habitats associated with the targeted species.

As of November 2011, five independent FWRI fisheries research projects use telemetry to answer questions related to movement patterns, habitat use, or spawning movements of species in these locations:

Mutton snapper, Lutjanus analis
Black grouper, Mycteroperca bonaci
Nassau grouper, Epinephelus striatus 
Yellowfin grouper, Mycteroperca venenosa
Goliath grouper, Epinephelus itajara

Collectively, FWC projects have 240 receivers deployed in waters around the state to detect tagged animals. Collaborations with other institutions provide an additional 146 receivers, expanding the spatial coverage in the following areas:

Charlotte Harbor
- Charlotte County SeaGrant Extension (13 receivers)
- National Oceanic and Atmospheric Administration Fisheries Service/Florida State University (10 receivers in Everglades)

Florida Keys/Dry Tortugas
- Mote Marine Laboratory (9 receivers)
- U.S. Geological Survey (7 receivers)

Florida east coast, FACT Array
- Kennedy Space Center/Florida Program for Shark Research (52 receivers)
- Florida International University (26 receivers)
- Bimini Biological Field Station (29 receivers)

Past telemetry studies at FWRI have tracked movements of species in various other locations:

The FWC's extensive statewide network of receivers, in conjunction with receiver arrays from collaborating partners, maximizes the space and time over which researchers can monitor individual tagged animals. Ultimately, these data provide insights into a multitude of behaviors and movements, which aid in constructing better management plans and assessing their effectiveness.