Dolphin feeding frenzy

The water began to boil off the starboard side of the boat, churning and splashing amid the smooth ocean swells. Dorsal fins popped up in alternating pairs and small fish jumped haphazardly out of the water as if it was too hot for them. Soon, a flock of petrels and shearwaters began diving on the roiling patch. Then, a large dolphin launched itself steeply into the air. It was a feeding frenzy.

The source of the commotion was probably a large school of herring or anchovies. Every once in while the action subsided, leaving the shearwaters floating calmly on the swells, waiting. When the dolphins located the school again, the chase was on, and the birds took to the air. And so it went for about 20 minutes before the boat continued on to Espanola.

Two species of dolphin prowl the seas between the Galapagos Islands: the common dolphin and the bottlenose. The feeding frenzy was driven by dozens of common dolphins. They have a longer, more narrow “nose”, a more upright dorsal fin and a brighter white underside than the bottlenose.

On a trip back from Punta Pitt a few days later, the boat was surrounded by bottlenose dolphins, which have a characteristically blunt nose, a dorsal fin with a backward curve and a gray color that fades more gradually to buff. They started out rhythmically breaking the surface of the water at some distance and then converged toward the boat, eventually “riding” its bow wave only a few feet away. Periodically, they came to the surface, spraying water from their blowholes and diving powerfully back into the water with a massive splash. Judging from the speed of the boat, they were swimming at a peak of more than 20 mph.