Bt/BtI responses

Thanks folks for the replies....Reason for the original post was for ref. of
dead fish in some ponds last summer where the users swore the dunks killed
their fish, but when I checked the outlying facts, i.e., neighbor spraying
trees w/Malathion, or blowing grass clippings into pond after applying weed
& feed, Washed patio furniture 10' away w/bleach etc., but no....It was the
darned mosquito dunks that got blamed....Even a name brand seed/fertilizer
rep said they kill fish...Then again countless others swear by them....