Alan,
Your post reminded me of an article I read where they use clams to monitor the water quality at the main water treatment plant in Warsaw, Poland.
If the clams detect dirty water, they close their shells, and that sends a signal to stop the output of the plant.
It is worth clicking on the link below, just to see the first picture in the article. It is a clam with a magnet on a spring cemented to his top valve!
https://tinyurl.com/8yjmhpdr
