Hard to tell without a better close up picture of an individual strand by itself but my guess is Curly Leaf Pondweed.

Fluridone (Sonar A.S.), Aquathol K, Reward, etc.

https://aquaplant.tamu.edu/management-options/curly-leafed-pondweed/

www.hoosierpondpros.com


http://www.pondboss.com/subscribe.asp?c=4
3/4 to 1 1/4 ac pond LMB, SMB, PS, BG, RES, CC, YP, Bardello BG, (RBT & Blue Tilapia - seasonal).