For example, fish swimming quickly through regions of high turbulence are unstable and show irregular pitching motions. This sensitivity to vertically oriented perturbations suggests that correction for pitching, which requires the production of vertical forces either anterior or posterior to the centre of mass is more difficult than for disturbances from other directions. Webb found that flow surges would displace fish similarly from their holding stations near cylinders regardless of their body
morphology, and that rolling perturbations induced by jets of water were more quickly corrected than perturbations that produced slip, yaw or pitch motions