I always blow the grass away from the water for several laps until I am far enough away to avoid throwing the clippings in the pond. I can only mow my dam (the remainder is wicked dangerous for mowing) and the dam is not too steep for my zero-turn. I did line the dam shore with 6 to 10 inch rock that would help me not get too deep into the pond should I slide close to the water and I mounted tow lugs to the mower frame in case my 8N had to be employed to pull the mower out.

I wouldn't worry too much about the clippings currently in your pond, but would avoid it in the future. Manual remove is an option at this time, but aside from being unsightly, it's not going to be noticed in a month or two. Like Dale said, if you leave a stand of taller "stuff" at the shore, it can act like a filter and block a lot of clippings from getting into the water, but now you have, what most consider, weeds at the pond shore. I end up with that row of vegetation at the shore and a weed-eater is used to knock it down. So long as you attack the weeds from the proper direction, the clippings, for the most part, get thrown back to the bank.

Brush hogs do tend to throw to one side as well and you could start your first lap around the pond about 3 or 4 laps out and work your way in to the bank. I do like your idea of getting a sickle bar and that would probably be best, BUT at my place it would only mean more work so I have not got one.

Fish on!,
Noel