I don't want to come off as a tree hugger here, but a few things come to mind. First, a riparian barrier between field and water encourages beneficial insects and birdlife, which in turn enhance the pond life. Fish have some shade to hide in, as do the amphibians they feed on (depending on species obviously). In my experience with 3 ponds on 100 acres, riparian barriers are a good thing. But if they are interfering with access to fishing, then selectively cutting back access portals makes sense.
This brings up the question of herbicides for the control of riparian plants. No matter what formulation is used, using it introduces toxins to the water column, and that will have negative consequences for pond life. Selective removal with a backhoe or periodic cut back with the brushcutter seem to be the best solutions in my case and may work for you. Admittedly, I do have a backhoe attachment for my tractor, so that is easy for me to say. Even so, it seems to me that as land stewards we have a bit of an obligation to ensure all our land management decisions enhance the ecosystems we are looking after and that we pass them on to the next generation in better condition than we found them. Not sure the liberal application of 24-D at the waterline fits that criteria. Just a thought and no doubt a controversial one, for which death threats will seem the only reasonable response to many.