Bayer contains Cyfluthrin, which is extremely toxic to fish and inverts.
"Like most pyrethroids, it is highly toxic to fish, invertebrates, and insects"
https://en.wikipedia.org/wiki/Cyfluthrin
"Cyfluthrin is highly acutely toxic to bees and fish.
(Just one part per billion can kill some fish species.)
Sublethal effects occur at even lower doses; less than
one part per trillion caused adverse effects on juvenile
minnows. E
cosystem-level tests have shown that
cyfluthrin affects many organisms in pond ecosystems,
including algae, zooplankton, nematodes, insects, and
fish."
https://www.fluoridealert.org/wp-con...facts.1994.htm