DNA in seawater reveals misplaced hammerhead sharks

This modern technique identifies traces of the sharks’ presence with out catching or disturbing them. Acting like faint organic footprints left within the sea, it detects fragments of genetic materials floating within the water to disclose the place the sharks have been. In a latest research printed in Frontiers in Marine Science, FIU marine biologist Diego Cardeñosa, who works with FIU’s Institute of Environment and the Global Forensic and Justice Center, demonstrated how the brand new take a look at can assist scientists find and defend endangered shark species.

Tracking Elusive and Endangered Species

Smaller hammerhead species such because the scalloped bonnethead, scoophead, and Pacific bonnethead have been devastated by overfishing, leaving so few that researchers wrestle to seek out or research them. Their habitats and actions stay poorly understood, making conservation troublesome. Cardeñosa’s new environmental DNA (eDNA) approach may lastly change that by serving to scientists pinpoint the place these critically endangered sharks nonetheless reside.

“Just by screening different locations along their distribution range from Mexico to Northern Peru, we can identify high-priority areas where conservation resources might be needed,” Cardeñosa defined. “The short-term goal is to find these three species, as they’re likely among the most critically endangered coastal sharks in the world.”

Searching for the Last Refuges

Cardeñosa believes these species had been as soon as frequent earlier than many years of overfishing drastically decreased their populations. They now survive principally in shallow, distant coastal areas which might be troublesome to watch and the place fishing rules are weak. His analysis focuses on Colombia’s Uramba/Bahía Málaga National Natural Park, one of many few locations the place these sharks may nonetheless be discovered.

“You can drop a hook and line there and, within 10 minutes, catch one or two of these species,” he mentioned. In most different locations, sightings are almost nonexistent. The scalloped bonnethead was final seen in Mexico in 1994, whereas the scoophead was final documented in 2007. In Honduras, certainly one of these species was lately rediscovered after many years with out a single document.

“That’s how hard it is to find them,” Cardeñosa mentioned. “It’s on us if we want to act to protect them or if we just let them slip away.”

Preserving a Piece of Evolutionary History

For Cardeñosa, the mission is about greater than conservation.

“A lot of these are some of the most derived or newest shark species on the evolutionary scale,” he mentioned. “If they disappear, we’re also losing a piece of our planet’s evolutionary history. Extinction is forever, and that’s enough reason for me to do something.”

A Powerful Tool for the Future of Marine Science

Cardeñosa hopes his work will encourage larger consciousness and appreciation for these often-overlooked sharks and reveal the ability of environmental DNA.

“It’s fascinating that you can take a simple water sample and know whether a species was there or not,” he mentioned.

By revealing the place hammerheads nonetheless exist, this analysis helps information conservation priorities and maximize the influence of safety efforts. Beyond hammerheads, the identical water samples can maintain genetic details about different marine life. Once collected, the DNA may be preserved in laboratories for years, permitting future scientists to review further species that when swam by the identical waters.