Scalloped hammerhead sharks are critically endangered. But the discovery of a schooling population in the Caribbean is giving local researchers hope. Blickwinkel/Alamy Stock Photo

Thanks to David Shiffman writing in Hakai Magazine:

In the Caribbean, Hammerhead Sharks Return to School

The detection of schooling behavior is a promising sign of recovery for this iconic and endangered animal.

Hammerhead sharks—fish with pronounced oblong heads and bodies as long as small cars—are unmistakable. Seeing one of these critically endangered animals is a thrill, but seeing nearly a dozen plying the water side by side is worth writing home about. This was especially true for Mauvis Gore and her colleagues when, in 2022, they saw a group of scalloped hammerheads off the Cayman Islands—the first time since the 1970s that hammerheads have been seen schooling in the Caribbean Sea.

“It was just luck, I think,” says Gore, an ecologist at Scotland’s Heriot-Watt University. Gore and her colleagues were exploring the Cayman Trench, a deep rift in the Caribbean seafloor, using underwater video cameras. “I saw this thing swim across the screen, and it was a hammerhead—you cannot miss a hammerhead shark, and it can’t possibly be anything else,” says Gore. “And then more hammerheads followed! It was just so wonderful to see. I could not believe it.”

In the Pacific Ocean, near the Galapagos Islands, divers routinely see scalloped hammerhead sharks schooling in groups that are hundreds strong. Huge schools used to be common in the Caribbean, too. But as hammerheads have inched closer to extinction, there just haven’t been enough left to school in most of their range, which extends throughout much of the world’s tropical and temperate waters…

Read the whole article here.