You might want to reconsider taking such action - especially if this is a natural pond. It might be better to work with it instead of working against it. Perhaps you could remove a lot of parrots feather and try planting some other plants in there to increase your diversity. Your pond, while shallow, very likely provides critical habitat for a lot of amphibians that are in your area as well as countless other organisms. Few people realize just how important those shallow, fishless wetlands are to maintaining amphibian populations.

Not to try to scare you, but also it might not be legal to make any major modifications to it (i.e. filling it in to create a bog).

What I would do is take advantage of what you have, remove a lot of the parrots feather, find plants that will survive in it as is and enjoy it - go out there in the spring and see just how many amphibians are using it, too.

~Mike

Some thoughts on plants you could use:

-Pickerel Rush
-Golden Club
-Skunk Cabbage (for the edges)

...I'm sure more will come to me later

consider putting a live sphagnum moss that can tolerate the heat and sun of your area.
Learn how this plant grows and how to place it on moist ground at the edge of water.
It will take it a while to establish but if you get conditions correct it will take off and slowly,.... slowly create a floating acidic bog in a section of your pond that is suitable for all sorts of wildlife and acidic growing of native bog plants.
The most important thing is the water quality that filters into your pond from the river.
Sphagnum moss doesn't take well to polluted waters and will not survive any salt water.
It isn't cheap and you must buy it live. Good sources for living sphagnum moss would be some nurseries that sell carnivorous plants.
The acidic bog is commonly a old pond that has filled in with living sphagnum moss. As the living top layer grows the moss below decays into a moist peat, peat moss.
Sphagnum moss must always be moist and once its established will spread out into shallow water forming hummocks. Key word is slowly, but once it gets going it is wonderful.

Here is a link that might be useful: sphagnum moss culture