Tracking Fish and Invertebrates with Acoustic Telemetry

Technological developments over two decades have brought acoustic telemetry into mainstream research, enabling biologists to monitor animals at the individual level to investigate many behaviors.
Seine Net spotted sea trout
An example of a population-level study: a 400-foot seine net is deployed to catch large numbers of fish (left); in this case, the target species is spotted seatrout (right).

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.

 

Biologist implanting tag. captioned below Divers implanting a tag. captioned below
Biologists implant tags in the abdomens of fish both out of the water (left: Tampa Bay spotted seatrout) and on the ocean floor (right: Dry Tortugas mutton snapper © C. Parsons).
Diver working on a VEMCO VR2W receiver. Biologist with a VEMCO VR100.
Left: A VEMCO VR2W receiver (visible at the top of the PVC housing) logs the date, time, depth, and tag number when a tagged animal swims within its range.
Right: A VEMCO VR100 handheld receiver lowered over the side of the boat allows a biologist to locate and follow a tagged animal.

 

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:

Florida West Coast

Goliath Grouper Biologist working on a red drum. Biologist releasing a sawfish.
Gulf of Mexico
Goliath grouper
(Epinephelus itajara)
Nearshore Tampa Bay
Red drum
(Sciaenops ocellatus)
Charlotte Harbor
Smalltooth sawfish
(Pristis pectinata)

 

 

Florida Keys and Dry Tortugas

Divers working on a fish. Mutton snapper
(Lutjanus analis)

Black grouper (Mycteroperca bonaci)

Nassau grouper (Epinephelus striatus)
Yellowfin grouper (Mycteroperca venenosa)

Goliath grouper (Epinephelus itajara)

 


Florida East Coast

Common snook release Biologist with snook. Common snook underwater
Riverine
Common snook
(Centropomus undecimalis)

Small-scale fat snook
(Centropomus parallelus)

Largemouth bass
(Micropterus salmoides)
No-take reserve
Common snook
(Centropomus
undecimalis
)
Offshore/inlet/estuaries
Common snook
(Centropomus
undecimalis
)

 

Small map showing areas monitored with acoustic telemetry
View a map showing areas monitored with acoustic telemetry receivers by FWC and its partners.
(PDF 1.05MB)

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:

Red Drum tarpon release spotted seatrout
Atlantic Coast
Red drum
(Sciaenops ocellatus)


cooperative study with
NASA-KSC Ecological program
Florida West Coast
Atlantic tarpon
(Megalops atlanticus)
Tampa Bay
Spotted seatrout
(Cynoscion nebulosus)

 

Queen Conch Tagged lobster releasing common snook
Florida Keys
Queen conch
(Strombus gigas)
Florida Keys
Caribbean spiny lobster
(Panulirus argu)
Caloosahatchee River
Common snook
(Centropomus undecimalis)


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.

Mutton Snappers
FWC scientists use telemetry to determine the movement patterns of spawning
mutton snapper within and beyond protected areas in the Dry Tortugas.
(Photo credit: © Don DeMaria)



FWC Facts:
Gulf sturgeon are considered anadromous, from the Greek, meaning fishes that travel back and forth between fresh and salt water.

Learn More at AskFWC