Sound artist Andreas Bick has published an interesting sound he found over a lake in Germany that suffers from nutrient pollution.
Last year I dunked my hydrophone into the green, muddy water of the lake to see if I can hear anything at all. Surprisingly I found a constant chirping that was onmipresent in the lake, I heard it everywhere I put my underwater microphone in the waters, even in ditches around the lake. I have no idea what species this is, I guess it must be a small water bug that seems to find perfect conditions in the polluted lake. This example is a close-up of one bug I recorded from a jetty in Lembruch. The other sounds come from the waves lapping against the jetty.