Here is a big question for the smartest of the smarts. I have a neighbor that has a7 acre lake. A few years he used KARMEX to kill Lilly pads. I understand that it is NOT for use in ponds. Here is the question are the fish safe to eat? Place is loaded with LMB up to 10+ lbs and some need to be removed. Anybody know?

I read that Karmex is allowed to be used in some waters in Canada, but have read nothing about the fish. maybe one of our friends to the north of the border can shine some light on this

If he needs to find a home to a few 10+ lb LMB, I might be able to help!

He wouldn’t care..... he told me after I caught that hoss why didn’t you keep it!

Does anyone know how long the residual effects of KARMEX last in a pond and in the fishes flesh ? Thanks

We have discussed this chemical brand name KARMEX in the past; chemical name Diuron.
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=33898


My question is if the neighbor used Karmex in the pond and it causes damages is he legally liable? Maybe ask him?
Here is a link to IMO a pretty good informational summary from Pesticide News.
http://pesticides.news/2017-12-05-d...-diseases-and-environmental-impacts.html

Important pond biology information in the article is: "Water contamination may result in behavioral, biochemical, developmental and mortality of aqueous organisms such as amphibians, annelida (aquatic worms), aquatic plants, cnidaria, crustaceans(zooplankton) echinoderms, fish, insects, molluscs, nematodes(round worms) and flatworms, phytoplankton, terrestrial plants and zooplankton." All of them fish foods and important items for the health of the water body.

Evidently it has a pretty big impact on the food chain that the fishery community depends on for production and health. IMO it likely significantly degrades the ecology of the pond.

Since the chemical is not labeled for pond or aquatic use, one has an extremely difficult time determining how much to use, although use is probably not wise if you value the short and long term usability of the pond or lake. It is Federally illegal to use in ponds thus one is legally liable for ALL damages that it causes.

Another part of the article says - " This chemical may also cause changes in blood chemistry, increased mortality growth retardation, abnormal blood pigment and anemia, as seen in animal tests in the laboratory.
Some other symptoms show decreased body weight of offspring, wavy ribs, extra ribs, delayed bone formation, reproductive and embryotoxic effects. Other side effects include methemoglobinemia." Thus IMO if there are pets drinking the pond water with Karmex it could affect their health. This also causes me concern if there are children swimming in the water where their absorbent mucous permeable membranes are exposed to the water with the Karmex dissolved in it. All the above is probably why it is not labeled for fish and recreational pond use!

Thanks Bill for the info, I have read the threads ( at least all that I have seen) but none have mentioned how long that the chemical stays active in water and fish. I guess since it isn’t intended for use in ponds info is lacking . Luckily the pond is down stream from me, the neighbor is 85 years old and don’t fish! Pond is loaded with LMB some very large, so I was wondering if the fish are safe to eat. Heard the half life of that stuff is100 years!
Thanks Mr Bill for any insight

Decay or ecological degradation depends on conditions. After a little web searching I found this from research in California.
Aqueous photolysis half-life 43.1–2180 days (pH 7 at 25º C)
Aerobic soil degradation 372 days
Anaerobic soil degradation 995 days
Soil photolysis half-life 173 days
Field dissipation half-life 99.9-134 days

Cattle fed small amounts, accumulated low levels of diuron in fat, muscle, liver, and kidney. Little tissue storage under field conditions is anticipated (EXTOXNET, 1996).

Fish and Aquatic Invertebrates. Diuron is toxic to fish and aquatic invertebrates. The LC50 (48hr) values for diuron range from 4.3 to 42 mg/L in fish, and range from 1 to 2.5 mg/L for aquatic invertebrates. The LC50 (96hr) is 3.5 mg/L for rainbow trout (EXTOXNET, 1996). Therefore diuron is moderately toxic to fish and to aquatic invertebrates

Bill thanks for the info.
It’s been almost 4 yrs since he used KARMEX in his pond...... I’m not sure about the time that it takes to dissipate in pond water ( I’m a dummy)