“…That individual fish have a harder time swimming against eddies “is not exactly shocking,” said Ty Hedrick, a biologist at the University of North Carolina at Chapel Hill who was not involved in the work. “After all, getting knocked around by turbulence in the water is probably going to require some extra energy.”
What was surprising, he said, was that the turbulence didn’t affect the fish in a school at all, a result that suggested the formation was somehow changing the water’s flow. But, at least for now, this finding holds only for giant danio swimming in strictly controlled lab conditions. “This is great,” Dr. Hedrick said, adding, “It’s a start, not a finish.”