Here is my reason why.
The minimalists use a lot of repetition in their work. A lot. The repetitive nature of the music reminds me of the constant, repetitive motion of the fish's fin movement, as well as their breathing. it kind of syncs up. The minimalists music is repetitive, but it does move on with a melody. the melody would be the actual motion of the fish through the water as they carry on the routine of their lives.
Make sense? I would be willing to send an MP3 to anyone willing to give it a try!