Hector from Anaheim, California writes
Contrac Blox Rodenticide and other similar products do have active ingredients that are toxic to fish, however secondary poisoning from a rodent that consumed the bait is generally only a concern with birds of prey or other scavengers that would actually eat the rodents who had consumed the bait. Per the SDS: "Do not apply this product directly to water or to areas where surface water is present or ot intertidal areas below the mean high water mark. Runoff also may be hazardous to aquatic organisms in water adjacent to treated areas...Bromadialone water solubility is extremely low (<0.1mg/l)."
We would recommend not using rodenticides near the pond or in a way that may contaminate the pond. You could use snap traps inside a bait station in areas outdoors where you do not wish to use rodenticides, such as the EZ Snap Rat Bait Station.
Answer last updated on: 11/01/2016