Hi folks. I have a question to ask for my neighbor. He has had a small well water fed pond ( 25'-30' in diameter ), for over 30 yrs., and all of a sudden this year, ALL the vegetation has died, as has all twelve of the Koi he had in there. I told him i'd try to find out what the heck had happened, and hope someone might have an answer. It isn't very deep, maybe waist high at the deepest, so you can clearly see the bottom. It looks like someone put a giant vacuum cleaner in there, and sucked every living thing up?

Most likely, whatever killed the plants created some rotting mess that sucked O2 from the pond.

Do you have an idea, what could have killed plant life?

Crayfish can denude a pond of all vegetation...I've witnessed it many times, especially in smaller BOWs. Welcome to the forum, RJD.

Have your friend look for crayfish signs - burrows etc. You can trap crays readily if you suspect this is the cause.

Now if only we could train crayfish to exclusively target coontail!

Will do my friend, but after reading a few posts on here, i'm beginning to think that maybe it's something about the water. Too much of this mineral, or not enough of that mineral? I suggested he test his PH/Salinity, not only right out of the pond, but also testing the well water that is always flowing into the pond. Good suggestion, or not?

PS: Thanks for the "Welcome"

You can't go wrong with knowing the water quality of the pond and the source, so that's certainly a good suggestion. I would not forget about the crawdads, however.

When I bought my place it had a silted in 100 x 170 foot pond that was only 2 foot deep...no vegetation what's so ever. Long story short, it turned out to have a lot of crawdads in it and no fish to act as predator. Take a crawdad trap (or even a long handled dip net with finer mesh) and sample the pond. My old pond would produce 20 to 30 crawdads in an hour or two using a wire trap and some dry dog food. The crawdads were northern virile species and were typically 1 to 3 inches long. Side note: I threw some creek fish in the pond "for fun" and within a couple years the crawdad trap couldn't catch more than a few and the plant life started to return (mostly FA). The creek fish turned out to be GSF and there was a thousand or so when we drained the pond for renovation.

Do you have access to any creek fish? you could catch any ole' pan fish and plop it in a 5 gallon bucket full of the pond water with an air stone and see if it lives for a few days. Keep it in a cool, place like a basement with a cover and see if makes it. Kind of a canary test.

I can not really blame an overpopulation of crawdads on the death of the fish really. And I would not be able to suggest why crawdads would survive bad water over the Koi. Were the Koi fed or did they rely on the vegetation?

Crayfish? You've been out of Louisiana much too long Anthropic!

No feeding of fish, Quarter Acre. They ate what they foraged for. I have a 50' x 100' pond myself, and we both live next to a Trout stream. I have Blue Gills, and Black Bass in my pond, so maybe he could do what he's done before, and come down and catch some Blue Gills, and put them in the pond? I have a lot of Salamanders, and have raked the bottom of my pond, and never saw one crab/crawfish/crawdaddy. I've never heard him talk about any of the above mentioned critters either. One recent Muskrat in his pond, but he trapped it quick, and took it to a nearby swamp.

Sounds to me like the pond was sprayed with herbicide or herbicide runoff entered it, which killed the plants, depleting the oxygen in the water, or simply killed the fish and plants simultaneously.

I can guarantee that's not the case John. Neither he, or i, use any chemicals, and there are no farms where we are. We live in the hills, with the Bears

You have to talk in terms Yankees can understand. They may not even know what a goggle-eye or sac-a-lait is!

Sorry, didn't know if you might live in a suburb with close neighbors.

You have no idea where i live, or what the area contains John, so you have nothing to apologize for. Every opinion is appreciated, and it may be the one that solves the mystery. Thanks for everyone's input

True! Better stay away from Boudin, Lagniappe, and Courtbullion for now, just to be safe.