Profiles of three-dimensional velocity have been collected at the site of an intentional-tracer diapycnal diffusion study. The velocities can be broken into long-wavelength and short-wavelength (fluctuation) components. The Reynolds stresses of the fluctuations, computed in the direction of the long-wavelength shear, are significantly anticorrelated with the shear. This is consistent with positive eddy viscosity, and with energy transfer to the fluctuations. The transfer rate is near the dissipation rate required to explain the observed diapycnal diffusivity. The fluctuations and stresses are most likely internal wave signals, so this result is consistent with co-located growth and decay of small-scale internal waves. Implications are that the decay rate of small-scale waves may depend on the local energy flux to those waves in addition to their behavior. ¿ 1998 American Geophysical Union