Pond Boss Forums INTRO Questions & Observations Drained small pond, how to kill remaining fish....

Sermon.
US Fish and Wildlife Service (Fish Hatchery Management. 1982-1992. pgs 90, 93) used to recommend using chlorine for disinfecting fish ponds and wild fish removal. I don't think they recommend chlorine treatment any more for the following reasons.

Adding reactive clorine to natural waters that contain organic compounds has been discovered to create chemicals in a group called THM, TCM, and DCM's; (hereafter TCM's). These are residuals of the chlorine treatment. Chlorine ions react with the organic compounds present in the water to form new chemicals. Technical names for your further study are Trihalomethane, Trichloromethane, Dichloromethane, Chlorine dioxide, bromodichloromethane, dibromodichloromethane and chloroform. These complex chemicals are nonpolar which means they are fat or oil soluable, relatively stable and will deposit in plants & animals and they will travel up through the food chain which is also called bioaccumulative. This means that eventually the fish will contain TCM's if they are raised in the water body that possesses TCM's. If you eat the fish then you absorb the TCM's from the fish. TCM's are still being studied but they have affinities for carcenogenicity and mugtigenicity i.e. cancer causing and known to deform sperm or sex gametes in some animals. One should be able to research more about this by using a web search engine. I have not done this and would be interested in a summary of what anyone may locate about this topic.