The Louisiana Department of Wildlife and Fisheries (LDWF) in a collaborative effort with several fisheries-based agencies, successfully tagged 10 whale sharks during two recent trips in the Gulf of Mexico. This represents the largest number of whale sharks tagged at one time in the northern Gulf.
The tagging effort was a joint venture between the University of Southern Mississippi Gulf Coast Research Laboratory, National Marine Fisheries Service, Mississippi Laboratories, Flower Garden Banks National Marine Sanctuary, On the Wings of Care and LDWF. The team is hoping the project will reveal precious information about the little-studied fish.
“Historical information on whale sharks in the northern Gulf of Mexico is lacking,” said LDWF Assistant Secretary Randy Pausina. “We’ve had great success with many other fish tagging ventures and hope that this effort has similar results, providing a wealth of data to assist in the conservation of this species.”
Tagging Whale Sharks
Despite being the largest fish in the ocean, the whale shark is one of the most elusive animals to scientists due to their offshore, nomadic existence. They are extremely difficult to find outside of a few known seasonal hotspots; therefore, obtaining data on this species is extremely challenging and expensive.
“If the tags stay on for a significant amount of time, we will learn a great deal about how these sharks use the waters of the northern Gulf of Mexico, as well as where they go in the winter time, which is still a mystery to us,” said Dr. Eric Hoffmayer, a Research Fishery Biologist with NOAA Fisheries Service, who has been studying whale sharks in the northern Gulf for 10 years. “It is still unclear whether whale sharks are residents in northern Gulf waters or simply seasonal migrants from the Caribbean Sea or beyond. Hopefully, the data acquired from these tags will shed some light onto this research question.”
One of the most accurate and useful tools for studying whale shark movements is telemetry, which involves attaching satellite transmitters to the sharks. Other behavioral information beyond the shark’s movements can be inferred by assessing oceanic and physical conditions around the shark.
The satellite tags provide temperature and depth data every 10 to 15 minutes as well as an estimated position each day for the duration of the tag’s deployment. The at-large periods for these tags ranged between four and 12 months. In addition to the standard satellite tags, three position tags were also deployed, which send real-time location estimates to the satellite when the shark surfaces and the satellites are overhead. These tags should report for up to six months.
“Another important factor contributing to the success of this project and our whale shark research over the years has been the participation by the public in our Whale Shark Sighting Survey,” said Jennifer McKinney, Research Technician with the University of Southern Mississippi’s Gulf Coast Research Laboratory. “After receiving several reports from the offshore community about whale sharks in region, we mobilized a trip to conduct the tagging. Due to public participation, we knew exactly where to focus our efforts and therefore had great success.”
The Whale Shark Sighting Survey can be found at www.usm.edu/gcrl/whaleshark. The survey has been an increasing success over the years, in which the general public has been actively involved in the whale shark research program through their participation.
For more information about this species, please reference the following — Whale Shark Fact Sheet.
Funding for the satellite tags was provided by the International Foundation for Animal Welfare and World Wildlife Fund. The Louisiana Department of Wildlife and Fisheries manages and protects Louisiana’s abundant natural resources. For more information, visit www.wlf.louisiana.gov.
Bonny Schumaker with On the Wings of Care, a non-profit agency, has provided aerial support for whale shark tagging trips since 2010.