Last year, the Aquarium began contributing funds to purchase sonic tags for use in a research project designed to better understand the reproductive habits of elusive Sand Tiger Sharks (Carcharias taurus). Months later, that work is slowly starting to bear fruit.
The expedition is being conducted off the shore of North Carolina and represents a partnership between globally renowned, nonprofit shark researcher OCEARCH and The North Carolina Aquariums. Researchers’ initial goal was to capture and tag 30 mature female Sand Tigers larger than seven and a half feet in length. These tagged sharks’ movement will be tracked to determine the habitats they prefer for breeding, gestating and, eventually, raising their pups.
A Sand Tiger Shark swims through the Secret Reef exhibit at the Tennessee Aquarium
So far, researchers have managed to capture two females, and researchers are working to improve receiver coverage in shore and off shore near the Cape Fear region off Southern North Carolina, says Madeline Marens, an aquarist with the North Carolina Aquarium at Fort Fisher.
“We were fortunate to encounter a large female on July 12, and equipped her with an internal acoustic transmitter,” Marens says. “These transmitters have a battery life of 10 years. We also were able to get some standard measurements and a fin-clip for genetic testing.”
North Carolina Aquarium at Fort Fisher's Madeline Marens tags a female Sand Tiger Shark caught off the coast of North Carolina on July 12, 2017
In the wild, Sand Tigers can reach impressive lengths of more than 10 feet. This female was 249 centimeters, or about eight feet two inches. The tags were purchased using funds provided, in part, by the Tennessee Aquarium. The shark was also darted externally, which will be used to quickly identify her, if she’s encountered on future expeditions.
Female Sand Tigers are sighted off the North Carolina coast year round, Marens says, and tagging will continue through the fall. In August, the researchers will switch from fishing off one of the aquarium’s vessels to long-line fishing with a local commercial fisherman. Researchers are targeting coastal shipwreck sites and reefs where these sharks often are sighted.
One of four Sand Tiger Sharks in the Tennnessee Aquarium's Secret Reef exhibit. This species can reach lengths of up to 10 feet in the wild.
The project is still far from achieving its tagging goal of 30 females, but the work continues and represents an important step to achieving a better understanding of this species, which like all sharks, is imperiled in the wild by human activity, Marens says.
“We are interested in learning how long they stay in North Carolina and to quantify how they are using habitats,” she says. “Mature females are important to the population as they sustain future generations. We hope to learn how they utilize the North Carolina coast and identify essential reproductive habitats.”
In honor of the Sharkfest celebration on Aug. 4, the Aquarium will present two screenings — at 5 and 6 p.m. — of the thrilling documentary “Shark Clans.” This documentary imparts the thrilling sensation of cage diving with Great White Sharks off the coast of Southern Australia. Oft-misunderstood and much-feared, researchers have discovered that groups (or “clans”) of these sharks return to the Neptune Islands year after year and appear to recognize a social hierarchy. Proceeds from the screenings of “Shark Clans” will help fund the continuing Sand Tiger Shark research off the North Carolina Coast.