Pond question

[sawtooth]

Hello friends,

I recently had a pond management service come in and spray one of my ponds for duckweed. They told me the chemical was harm harmless to wildlife but within about seven days after they sprayed the pond now has hundreds of dead bluegills all around the edges. Obviously the chemical had some affects but is this normal? I’m going to call him today as soon as he opens up I’m trying to figure out what’s going on. My guess is they either ate the duckweed and it killed them or since they were bedding and the duckweed was over top of them maybe had some effect since it was around the edges where they were on their beds. Thoughts?

 

[East30]

Could be an oxygen depletion issue. Duckweed and other possible plant life dying using up oxygen in the decay process?

 

[oosik]

If it were an oxygen issue you should have seen hundreds of bluegill surfacing and "air breathing". This would have been a day or so BEFORE they all died.

Did it actually kill the duckweed? Have you seen any live bluegill?

Experience would show - it's almost impossible to rid a pond of massive weed growth without affecting other pond inhabitants. What about your frogs - flying insects - crayfish - ??

 

[sawtooth]

It’s not oxygen but good idea. Only minimal part of pond was covered with duckweed just trying to stay ahead of the game. I’m going to look again but only bluegills dead that I can see. Nothing else so far. All fish died within a 3 day period too.

 

[oosik]

Sound to me like - the chemical used or the concentration used. Ask what was used and at what concentration.

 

[rekees4300]

Thoughts?

Instead of using chemicals to control weeds get some sterilized Grass Carp. My 1 acre pond was overrun by weeds for 15 years. Five years ago put 12 small Grass Carp in there and 2 years later they grew from 10 inches to 2 feet. Now ALL of the weeds are gone, even Cattails!

 

[MoKelly]

Instead of using chemicals to control weeds get some sterilized Grass Carp. My 1 acre pond was overrun by weeds for 15 years. Five years ago put 12 small Grass Carp in there and 2 years later they grew from 10 inches to 2 feet. Now ALL of the weeds are gone, even Cattails!

This is the answer. My neighbor did exactly this in his 3 acre lake an the results were amazing. They grow into big fish!

MoKelly

 

[sawtooth]

I actually just did this in my other pond I put in 40 sterile grass carp the same week I did the chemicals in the first pond. I used chemicals in first pond because I was told the grass carp couldn’t manage the duckweed. Wishing now I would’ve tried the carp first.

 

[ponytug]

FWIW: Grass carp do eat duckweed, it just isn't their favorite.

I hope that your pond recovers.

All the best,

Peter

 

[Jstpssng]

Just curious, what pesticide did they spray with?