I can completely understand both why you were very suspicious, and why this would be a good indicator.  Clams are sensitive creatures in terms of pollutants, and if they find something is wrong, something is probably wrong.  While I’d prefer to have a few other backups if I ran something like this using a systems that’s not too expensive to maintain, and provides a fairly straightforward answer is always nice to have on hand.<br><br>I’d put a ‘happy as a clam’ pun in there, but that’d be shellfish of me.,(reply>), @The Glorious Lobster Emperor And they test river water before it's tested. I think that's obvious but some people thought they are in filtered tap water,(reply>), I mean, he did point out in the video that these clams aren't the <b>only</b> way they check for water contamination. They're just one small part of the larger system that checks for water purity.,(reply>), Well, the clams probably aren't too happy to be used as poison sensors.,(reply>), They do something similar to test rivers and lakes her in Louisiana. Dept. of Wildlife and Fisheries will collect several fish, then send them to LSU med labs to check levels of mercury and lead and other chemicals. High levels may indicate that a refinery or chem plant upstream is releasing toxic chems into the water.,(reply>), I'm not one to clam up when it comes to a good pun.