2017 Research and Conservation Newsletters

A lot of a whale shark’s daily life is still unknown. Things as basic as their reproductive habits to how they use the water column throughout the day are still a mystery to researchers. One tool used to help find answers to these questions are satellite tags. Georgia Aquarium has used satellite tags to study whale sharks in Mexico, the Galapagos islands and in St. Helena in the South Atlantic Ocean. Satellite tags have a pretty rough life, though. They are relentlessly exposed to tropical sunlight while immersed in a corrosive seawater environment. The tags are designed with these conditions in mind to take some abuse and still report their observations. However, current tags aren’t designed with deep dives – like the ones whale sharks around St. Helena make in mind. The island of St. Helena rises very quickly from the ocean depths and within a few nautical miles of shore, you’re easily in depths of 1000 meters. The tags Georgia Aquarium uses for whale shark research are rated to survive depths of up to 1800 meters without being damaged from this crushing pressure. Unfortunately, a lot of the tags deployed were damaged during these extreme dives. Fortunately, though, there were two tags that successfully reported their movements and a third true-life message in a bottle story.

On March 5, 2017, biologist Flora Zauli, a member of a beach patrol at Espiritu Santo, Brazil, found a device in the sand. She brought it to Dr. Larissa Pavanelli who identified the item as a satellite tracker and was able to decipher the label on the tag and contacted Harry Webb. After Harry was given the coordinates and time of day where the tag was found, he plotted the course using Google Earth and learned that the tag drifted over 2,200 miles in 421 days. It is presumed that the tag detached prematurely from the whale shark and washed ashore after its oceanic journey. Looking through records, it appears that this tag never reported any data and may have been defective. However, all is not lost. Once we receive the tag at Georgia Aquarium, it may have a treasure trove of valuable data stored on it that can be retrieved once it’s connected to a computer. The greater revelation is that this incident can be used to help understand more how the ocean current moves from St. Helena towards the east coast of Brazil. This information helps us when we look for locations where whale sharks might be found. They are known for following the prevailing currents and not working against them to conserve energy. With this tag, there is now a connection from St. Helena to the beach at Espiritu Santo, Brazil. Because whale sharks are known to migrate large distances and can be found all over the globe, it’s important to identify potential “hot spots” or areas of interest to focus our efforts. Were it not for the beach patrol finding and reporting this tag, this new area of interest might have never been established.

Georgia Aquarium’s manta ray research at Marineland, FL was an important project for 6 years. With each year we added new components of research while dedicating our staff to the overall goal of understanding the natural history and population dynamics of these large, migratory rays. In 2018, our research and conservation team worked with our dive operations team to install acoustic listening stations along the sandy bottom of the Atlantic Ocean via SCUBA divers. These stations will be “listening” for individually coded acoustic transmitters affixed to the manta rays to monitor their movements. Five stations in total were deployed in the waters just off shore of Marineland, FL. This group of stations is called a receiver array and it will be used to record tagged manta rays that swim through the nearshore Atlantic Ocean at Marineland, FL. These stations have an underwater microphone called a hydrophone that picks up specially coded messages released by the transmitters attached to the rays.

Unfortunately, due to unforeseen weather circumstances, the research crew this year could not affix any transmitters to manta rays. But all is not lost, because there are still many tagged species of sharks, fish, and some rays swimming in the nearshore waters at Marineland. Using these receivers, we’ll be able to monitor the movements of animals equipped with the coded transmitters. 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 partner receivers.

The animals that Georgia Aquarium researches are found all over the globe, and so must the effort be to conserve their world, and ours. Ocean trash and single use plastics are a major threat to aquatic wildlife and the environment as a whole. Georgia Aquarium is becoming more involved in the conversation surrounding how we as humans can change this course, including attending symposiums, forums, and conferences worldwide. Dr. Al Dove, Vice President of Research and Conservation, recently traveled to Bali, Indonesia in late February to attend the World Oceans Summit. Organized by the Economist, the Summit brings together business leaders, government officials, investors, ocean advocates, and members of the scientific community for a constructive and solution-based dialogue regarding the future of the oceans and their inhabitants.

While in Bali, Dr. Dove also met with the team at Conservation International to talk about our collaboration later this summer, which includes conducting unprecedented full scale health assessments on free-swimming whale sharks. This expedition has been set for July 20 to August 13. Please be on the lookout for further communications regarding that trip.

Earlier this year, Georgia Aquarium Conservation Field Station (GACFS) employees and volunteers participated in the rescue of a dolphin calf who was observed tangled in fishing gear. The calf and its mother were spotted near Cape Canaveral, Florida in early January. GACFS and partner institutions including Sea World Orlando, HUBBS Sea World Research Institute, Harbor Branch Oceanographic Institute at Florida Atlantic University, Clearwater Marine Aquarium, Florida Fish and Wildlife Commission and University of Florida worked out a plan of action to free the calf of its entanglement under the supervision and authorization of NOAA’s National Marine Fisheries Service. The mother and calf were both safely restrained as the crew worked to free the small dolphin from the heavy fishing gear that had begun to cut into the young animal’s skin, leaving it with pronounced wounds on its fluke. Once the entanglement was cleared away, antibiotics were administered, a full medical exam was performed, and a satellite tag was placed on the mother so keep track of the pair post release. Conservation Field Station staff assist with these types of rescues along Florida’s coast throughout the year as a member of the National Marine Fisheries Mammal Stranding Network.

Also, the team at the Georgia Aquarium Conservation Field Station recently upgraded their marine mammal stranding equipment by designing and purchasing a new marine mammal ambulance. The brand new mobile unit will be a valuable asset to not only GACFS’ stranding response crew but for the larger National Marine Fisheries Mammal Stranding Network, of which the GACFS is a member.