Understanding the spatial and temporal use of habitats by animals is critical to resolving their role in the environment and formulating sound management plans. Fish movement data can be used to measure response to harmful environmental events (e.g. red tide events), water temperature, salinity, no or reduced fishing zones, and movement of other species (e.g. known predators). For tracking of aquatic animals acoustic telemetry has several benefits over traditional radio and satellite telemetry. Radio waves cannot transmit through saltwater, and given the very salty nature of Florida including tidally influenced creeks and rivers, radio telemetry is very limiting. Satellite telemetry, while very informative and functions well in saltwater, is also very expense. Financial constraints may limit the number of animals in a study. Acoustic telemetry is the best of both worlds, it works equally well in salt and freshwater and is cost effective.
Several companies including Vemco, Sonotronics and Lotek produce the hardware needed for tracking animals with acoustic technology. While most tracking equipment in Florida is purchased from Vemco, Sonotronics and Lotek offer compatible tags and receivers. Acoustic tags transmit an underwater sound aka ping that uniquely identifies an animal. When in range, the pings are registered on an underwater device called a receiver that also records the date and time. Multiple animals can be tracked at once with little effort on behalf of the scientists. After the original start-up of tag and receiver deployment, effort is only needed to download and service receivers at the leisure of the scientists (but at least once a year).
|A Goliath grouper poses next to an underwater|
|Lemon sharks circle around an underwater receiver.|
Vemco offers a variety of transmitters that can be ordered to suit the needs of a particular study. Tags can be ordered as coded or continuous pingers with battery life expectancy from 1-10 years. In addition, tags can be modified to include temperature and/or depth measurements. In addition to cost effective equipment, the potential for collaboration makes acoustic telemetry an extremely attractive method for tracking animals. Receivers will detect any and all compatible tags regardless of who owns the receivers or tags. As an added benefit, Florida is home to one of the largest collaborative groups using acoustic telemetry to study the movements of fish and sea turtles.
|A 4 year V-16 coded pinger made by Vemco.|
|Jim Whittington and Joy Young from FWRI |
surgically implant a transmitter into the peritoneal cavity
of a common snook.
|Locations of FACT receivers on the east coast |
of Florida. Note this map does not include the array
in the keys, Bahamas or Georgia.
The Florida Atlantic Coast Telemetry (FACT) group is a collaborative effort between various government, university, private, and non-profit groups conducting telemetry research. Currently there are 16 different organization in FACT including 6 universities, 4 state or federal governments, 5 non-profits, and 1 private group that range from Georgia, the east coast of Florida, the keys and the Bahamas. The use of compatible hardware and a commitment to share data allow member groups to track tagged animals beyond the scope of their own array. While each group maintains between 2-65 receivers, they have access to data from well over 200 receivers deployed in all habitat types found in Florida including rivers, estuaries and offshore. Tag IDs and receiver locations are maintained in a shared folder which is accessible by FACT members. When a member organization downloads their receivers, they check for other FACT tags. Detection data is shared directly between groups by sending vrl files over email. It’s that simple! The FACT array has proven successful in tracking fresh and saltwater species locally and across state lines. In the past few years we have tracked Tripletail from Georgia down to the Loxahatchee River and Lemon sharks tagged off of Jupiter to Georgia. Most recently, several white sharks originally tagged off of New England were detected on the FACT array near Canaveral. FACT is one of the largest collaborative arrays in the United States, sharing not only data but also reaffirming ties between research groups.
Fish move. We joke about that all the time in my office but it’s true. What is surprising is how far they move, and how fast. The fish you think just hang around your back yard may actually be using the entire coast. I was taken aback by the first barracuda tagged in Cape Eleuthera that was detected by receivers offshore of Palm Beach county in 2010. But the surprises have kept coming ever since. We encourage anyone or group conducting acoustic telemetry research to join FACT. Joining FACT will enhance your project by expanding the ability to track animals over a greater distance, and put you in contact with researchers using the same technology. And what scientist doesn't love more data and collaborations?
For more information or to join FACT please email Joy Young at Joy.Young@myfwc.com