EchoBERT echo dataset

The dataset consists of echo data collected at the Matre research station (61°N) of the Institute of Marine Research (IMR), Norway. Six square sea cages (12 × 12 m and 15 m depth; approximately 2000 m^3) were used. The fish's vertical distribution and density were observed continuously by a PC-based echo integration system (CageEye MK IV, software version 1.1.1., CageEye AS, Steinkjer, Norway) connected to an upward facing transducer which multiplexes between 50 kHz (42° acoustic beam angle) and 200 kHz (14° beam angle). However, only the 50 kHz data was used. Echo intensity, which is proportional to fish density, was integrated at 5 cm depth intervals. All six cages were respectively monitored by one CageEye transducer positioned at 20 m depth (below the cage bottom) and directed towards the cage center.