One whale shark successfully avoided research scientists for severalyears
FORT LAUDERDALE/DAVIE, Fla. – For humans, the concept of social distancingis really just a few months old. But for a certain whale shark, it’s somethingshe had been practicing for many years.
“Rio Lady,” a mature, 26-foot whale shark tagged in 2018, has been tracked byresearch scientists at Nova Southeastern University’s (NSU) Guy HarveyResearch Institute and Ch’ooj Ajauil AC for nearly 20 months, makingthis the longest, high-resolution position track for this globally endangeredspecies. But this wasn’t the first time she was tagged by researchers.
Eleven years prior and with support from Georgia Aquarium , scientistsfrom Mote Marine Laboratory and Ch’ooj Ajauil AC’s Executive DirectorRafael de la Parra first tagged her in August 2007 in the Gulf of Mexico nearIsla Mujeres, Mexico, where whale sharks annually aggregate to feed. Based onher ample girth, the researchers suspected the shark was pregnant. At thattime, the researchers used a pop-up satellite tag, and as the name implies,the tag “popped up” about five months later and nearly 5,000 miles away in thesouthern Atlantic Ocean, near the Rocks of Saint Peter and Saint Paul betweenthe African continent and Brazil. This led de la Parra to nickname her RioLady.
She wasn’t seen again until the summer of 2011.
“After the original tag came off, she kind of just went dark,” said MahmoodShivji, Ph.D., a professor in NSU’s Halmos College of Natural Sciencesand Oceanography and the director of NSU’s GHRI. “Talk about socialdistancing – she kept her distance for nearly four years. What’s alsointeresting is that Rio Lady’s new track is strikingly different from hertravel path after she was first tagged in 2007. Her recent 20-month journeyshows she travelled through the national waters of at least five countries inthe Caribbean and Gulf of Mexico, making you wonder where else she explored inthe years she wasn’t tracked.”
After she was first tagged, her long trek while pregnant to the middle of theAtlantic made this whale shark a media celebrity.
“Rio Lady immediately became a superstar for her species,” said Mote’s RobertHueter, Ph.D., lead scientist of the research in 2007. “She gave us a majorclue about where whale sharks may be giving birth to their young, in offshorewaters of the open ocean far from their nearshore feeding grounds.”
Rio Lady ditched her social distancing in 2011, reappearing annually at theMexico aggregation site from 2011 to 2018. Then in August 2018, de la Parra,working on a collaborative project with NSU GHRI scientists, tagged her inalmost the exact location where she was originally tagged. This time, theresearchers affixed a higher resolution Smart Position and Temperature (SPOT)satellite tag to Rio Lady’s fin, obtaining more accurate positions of herlocations from this tag.
“Rio Lady’s tag information has given us better insight into where whalesharks go, for how long and other factors that can contribute to ourunderstanding of these gentle giants,” said Dr. Alistair Dove, vice presidentof research and conservation at Georgia Aquarium. “Our research on whalesharks spans more than 15 years and it’s always an achievement when we havenew data to help us make informed decisions about where to look next orquestions that still need answers.”
Since her second tagging, Rio Lady’s journey has been remarkable. She hastraveled more than 9,621 miles in more than 600 days, which has included longforays into the Caribbean, the Gulf of Mexico and even a brief stop last monthnear the coast of Apalachicola in the Florida Panhandle. In 2020, she wastracked until February 15, when she “social distanced” herself for two monthsbefore resurfacing again last month in the Gulf of Mexico.
Researchers have learned over the years that while whale sharks mostly travelsolo, there are times they gather in large numbers in feeding aggregations.While Rio Lady is still practicing her usual social distancing, thanks totechnology, scientists are able to keep tabs on her in order to learn moreabout this amazing species.
Whale sharks are the largest fish in the sea, which along with mako sharks,tiger sharks, oceanic whitetips, sand tigers, smooth hammerheads and more aremonitored at NSU’s GHRI as part of ongoing research of the marine ecosystem.The GHRI studies many aspects of shark-life, from migratory patterns to theirgenomes, in order to protect these animals for future generations. Anendangered species, whale sharks are harvested for their fins, oils, meat andmore and can also fall victim to ship strikes during their migrations.
The trek of Rio Lady and other sharks NSU’s GHRI researchers have tagged canbe found at nova.edu/sharktracking.
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