I have a 1-acre, 30-foot deep pond stocked with fish (bass, cat-tail etc.), and ducks and goats etc.

Water Primrose all over the shore. Two years ago, we had a backhoe scrape about 10 foot into the water out (when water level was down a little). And I try to keep it clear but every year it comes back.

Last year, I tried to hand-weed and some insect living on there bit me all over (welts all over my body since I was in the water to take the weed out).

I would love any advice on how to at least manage it. Pond slopes gently down to about 30' in the middle. Weed grows out to about 10' from the edge. I live in Northern California. Trying to stay away from Chemicals given livestock...

Thanks,
-Ed

Grass carp? Perhaps keep livestock back from the pond to reduced nutrient load.

http://aquaplant.tamu.edu/management-options/water-primrose/

Thanks. I was also looking at: http://agrilife.org/aquaplant2/management-options/water-primrose/

These all talk about all the contact and systetic herbicides. I was hoping that someone with experience could tell me:
1) How to manage it without herbicides, and
2) Which herbicide is the most earth-and-animal-and-fish friendly.

I was thinking that when the water level is low (end of summer) and the primrose is out of the water, maybe a contact herbicide is better?

Thanks again,
-Ed

Grass carp... interesting. I will research this! Thanks!
-Ed

I would try Rodeo with the an aquatically registered surfactant.

Crayfish??

The only biological method that I would consider trying would be the goats. But I don't have high hopes. The other biological method would be labor intensive and you pulling it out. You found out how well that works.....

Any of the chemicals listed as "excellent" will work, follow the label for application rates. I would treat the plants when they are actively growing, that way the herbicide translocates to the roots. I don't know which ones of those the State of California allows into the state, or rather allows to be sold in the state.

controlled (or uncontrolled/accidental) eradication by flame?

Gasoline DOES float on water!

One act that we'd do in the ski show was have a couple guys barefoot through fire. Pour a gallon of gas on the water, light it just before they went past.

That might be frowned on now by the EPA but then it was a good show. The spray from your feet put the flames out, we didn't wear a vest, and we held out breath before we hit the flames.