Joe Roman’s Slate article details an astonishing instance of bispecies cooperation, as the humans and dolphins living around the southeastern Brazilian city of Laguna help each other fish.
Early on the morning I showed up, men were arriving on bicycles, red or green milk crates holding their nylon nets. They were deeply tanned, some in shorts, some in waders. Ivan Ferraz de Bem, in a wetsuit stretched over an ample beer belly, took a cast net out of his red dune buggy. A skull-and-crossbones flag tied to his bumper snapped in the stiff wind. Recently retired from a government job in Brasilia, he seemed to enjoy the hours by the shore––and those in the nearby bar to which he retreated when things slowed down even more.
As we watched the turbid green waters flow into the lagoon, a tall dorsal fin broke the surface, followed by a smaller one. A mother dolphin and calf swam in, the youngster staying close to its parent’s side, then headed out for rougher waters. Perhaps they found no fish or were just assessing the situation. These are wild dolphins—untrained, undomesticated—and it was clear that they run the show. When the dolphins aren’t around, one fisherman told me, it’s not worth fishing. Some gave it a try anyway, with an underhand toss into the blue. A few small fish were landed.
Another dorsal fin rose a hundred meters from the shore. “Escubi,” one man called out, recognizing the white scuff marks on the leading edge of the fin. The men broke off their chatter, dashed into the water. Thigh deep, almost motionless, they stood at the ready, a line of six, as if awaiting Escubi’s orders.
Most of the helpful dolphins have names: “Escubi” is a variant of Scooby Doo. “Filipe” is a Brazilian adaptation of Flipper. Dolphins have something like names among themselves, too—each has a signature whistle, and they recognize one another by their unique calls when they meet at sea.
Another blow broke the surface. Escubi lifted his dorsal fin, reversed course. One man splashed his net in the water, to convey where he was standing. Escubi signaled with a slap of his gray tail, then charged straight for the shore.
Dolphins can swim faster and accelerate more quickly than torpedoes, so the nearest fisherman, in an olive green rain jacket and black cap, cast his net quickly as Escubi approached. It spread like a spider web, landed on the surface, and closed below as Escubi veered to the left. As the fisherman retrieved the hand line, a large tainha, the local mullet, thrashed in the mesh.
Escubi headed out to sea. The men cleaned their fish. One tossed an anchovy to a razor-thin heron, feathers lifting like white caps in the wind.
Apparently the earliest recorded mention of this cooperation dates to the late 19th century, while dolphins migrating further south along the Brazilian coast have spread this tradition to a second community. I’d really love to know how the two species involved managed to create and sustain this unique cultural tradition.