acoustic_proportion_occupied_in_sea_water 1 [UUUU]P07 id: 07RO7YIE Acoustic proportion occupied is occupied volume divided by the volume sampled. Occupied volume is the integral of the ratio of acoustic_volume_backscattering_strength_in_sea_water above -90 dB to the reference value, 1 m2 m-2. For further details see Urmy et. al (2012) doi:10.1093/icesjms/fsr205.