direction that captive dolphins and other cetaceans swim.
All these studies have been conducted in the Northern
Hemisphere, with the vast majority concluding that captive
cetaceans spend the majority of their time swimming in a
counterclockwise direction. This directionally biased swimming
was first reported by Lilly [1], where he noted that
both of the observed captive dolphins would swim mostly
counterclockwise. A review of earlier studies [2] found that
studies conducted in both the United States and Russia had
described the counterclockwise directional swimming bias.
More recently [3], it was again reported that there was a
counterclockwise bias during sleep in Pacific white-sided
dolphins in the United States.