Pond Boss Forums INTRO Questions & Observations Pond Weed matted on surface

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.