Internal waves and fine-scale zooplankton sampling: Comment on Dewar-Fowler et al. (2023)

Dewar-Fowler et al. (2023; Mar Ecol Prog Ser 715:27-39) report on zooplankton carrying out short-term, unsynchronized migrations—or forays—into the surface layers. They used a motion-compensated zooplankton sampler consisting of an upward- and a downward-facing net. The sampler was deployed at a fixed depth, intending that individuals swimming into the nets are captured. We argue that it is warranted to account for internal waves when using this approach to address vertical swimming in zooplankton with weak swimming capacities.