I’ve been studying manta rays near the shore of our sister facility Marineland Dolphin Adventure in Marineland, Florida, for the past few years. Our team typically spends weeks performing aerial surveys, collecting tissue samples, and attaching satellite tags to monitor their movements. We’ve done this the last few years hoping to better understand if manta rays are remaining in northern Florida or migrating farther up the coast. We’ve all heard that the definition of insanity is doing the same thing over and over again and expecting a different result. So with that in mind, we decided to a take a different direction this year to answer the question: “Where are the manta rays?” We did so by listening for manta rays underwater.
How exactly does one “listen” for manta rays underwater? We installed a series of listening stations underwater. We did this because sound travels faster and farther in water than it does in air. We installed a group of five stations, the first of its kind in this area, and is called a receiver array. It will be used to record tagged manta rays that swim through the nearshore Atlantic Ocean of Marineland, Florida. These stations have underwater microphones called hydrophones that pick up specially coded messages released by the transmitters attached to the rays. It works in a similar manner to a pet with an embedded microchip. That chip has a unique code to identify the animal to the veterinarian when a special antenna is passed over it. Much like that antenna, the stations will record when a tagged manta comes near the station.
In addition to the manta, there are many tagged animals like sharks, turtles, and other fish swimming in the ocean. Using these receivers, and thanks to our new listening stations, we’ll be able to pick up those animals. When we retrieve the stations in the next year, we’ll be able to report those observations to other scientists as active members of the Florida Atlantic Coast Telemetry (FACT) Network. This participation will allow us to share data with other researchers as well as receive data when our tags are detected by other receivers. This is a wonderful example of different research and conservation organizations working together for the same cause.
This information is useful to understanding movements of manta rays and other animals, which is important in furthering our knowledge about them. Once we begin to understand these movements we can better understand and conserve mantas to reduce their exposure to man-made threats like fishing nets and habitat destruction from coastal development. Manta rays are considered “Vulnerable” on the IUCN Red List of Threatened Species, and at Georgia Aquarium we are proud to take an active role in their conservation.
Georgia Aquarium hopes to continue research efforts in the upcoming years to understand more about this graceful giant. For more information on research and conservation efforts, please visit www.georgiaaquarium.org/manta-rays.