Scientists have teamed up with tiger sharks to uncover the biggest expanse of seagrasses on Earth.
An enormous survey of the Bahamas Banks — a cluster of underwater plateaus surrounding the Bahama archipelago — reveals 92,000 sq. kilometers of seagrasses, marine biologist Oliver Shipley and colleagues report November 1 in Nature Communications. That space is roughly equal to half the scale of Florida.
The discovering expands the estimated international space coated by seagrasses by 41 % — a possible boon for Earth’s local weather, says Shipley, of the Herndon, Va.–based mostly ocean conservation nonprofit Beneath The Waves.
Austin Gallagher, a marine biologist from ocean conservation nonprofit Beneath The Waves, surveys a seagrass area within the Bahamas Banks.Cristina Mittermeier and SeaLegacy
Seagrasses can sequester carbon for millennia at charges 35 occasions quicker than tropical rainforests. The newly mapped sea prairie could retailer 630 million metric tons of carbon, or a few quarter of the carbon trapped by seagrasses worldwide, the staff estimates.
Mapping that a lot seagrass was a colossal process, Shipley says. Guided by earlier satellite tv for pc observations, he and colleagues dove into the glowing blue waters 2,542 occasions to survey the meadows up shut. The staff additionally recruited eight tiger sharks to assist their efforts. Similar to lions that stalk zebra by way of tall grasses on the African savanna, the sharks patrol fields of wavy seagrasses for grazing animals to eat (SN: 1/29/18; SN: 5/21/19, SN: 2/16/17).
“We wouldn’t have been able to map anywhere near the extent that we mapped without the help of tiger sharks,” Shipley says.
The staff captured the sharks with drumlines and hauled each onto a ship, mounting a digicam and monitoring gadget onto the animal’s again earlier than releasing it. The sharks had been sometimes again within the water in below 10 minutes. The staff operated like “a NASCAR pit crew,” Shipley says.
Researchers had beforehand recommended monitoring seagrass-grazing sea turtles and manatees to find pastures. But tiger sharks had been a sensible selection as a result of they roam farther and deeper, says Marjolijn Christianen, a marine ecologist at Wageningen University & Research within the Netherlands who was not concerned within the new work. “That’s an advantage.”
Camera-equipped tiger sharks like this one helped uncover the world’s largest seagrass mattress, penetrating areas too deep or distant for divers.
Shipley and colleagues plan to collaborate with different animals — together with ocean sunfish — to uncover extra submarine meadows (SN: 5/1/15). “With this [approach], the world’s our oyster,” he says.
