My graduate student is using Ethovision XT v17 to measure fish movement in response to conspecific alarm cues. Fish are placed in a 37L aquarium for these trials. We also would like to measure water column position, as fish often sink the the bottom in response to alarm cues. Is there a simple way to measure average and variation in veritical position by using the y-coordinates? Thank you, Craig Stockwell [email protected]