I'm in Tidewater VA, and have a 2 acre pond, aerated 24/7. The water gets really clear in Spring and pond weed grows from 8 ft deep to surface. It appears the pond weed is getting cut off near the bottom and is floating in mats on the surface that make fishing impossible.
I put 4 triploid grass carp in 2 years ago, could that be what is cutting the pondweed off at the bottom?
The pond has a lot of willow around the edge, which makes raking very difficult. Is Diquat my only option to get it back under control?
That looks very similar to sago pondweed. Crayfish will cut it up near the bottom and GC will tear at it as well. Some types of stemmed plants like that are meant to break free to float to a new location-that's one way they spread.
Some quantity of this type of plant is needed for several reasons.. fry habitat, nutrient uptake, insect cover and breeding substrate and some plants produce differing levels of O2.
Removing select areas of this would be ok but I sure wouldn't want to kill it all but this type of plant may require continued management to control but that's a part of it.
Some would be OK, but the pond is unfishable.
What other species of aquatic vegetation could be introduced to compete with the pondweed?
I'm not familiar with your area enough to say what grows best there, but If there's something that will out-compete pondweed you'll have bigger problems than you have now.
Chemical or Grass carp.. pros and cons.. 2-3 more GC may help the situation as long as they don't eradicate it completely because then you will start having turbidity issues as they rummage bottom sediments.
It's all about balance so a little at a time either way.
If there are a lot of weeds in the pond, TGC will go after another plant vs. try to chase down one that they are eating if it gets away and starts to float to the surface.
