Can not 100% identify from the pictures, but I can tell you a way I use in our area to remove something similar to it.
First you can do what is called a Winter Drawdown starting in November.
Miss. State Winter Drawdown PDF link While doing the drawdown you can make repairs or landscaping to pond. You can also do soil smaple and maybe spread lime in to get your PH balance. I would also recommend as deep in the south as you and I are if your water is clear to put in a pond dye during the draw down. This is to prevent any new aquatic growth. The March / spring storm runoff generally will fill your pond back up.
When water temps reach 60 around the first of March fertilize the pond. This will create good algea which turns the water greenish and prevents sunlight from causing more aquatic growth next year. It also provides food for fish to grow healthier.
Also add about 4 Triploid grass carp per surface acre to help with the aquatic growth.
If during the next summer you see it start to come back in any significant amount spray with Reward and add a few more Triploid grass carp.
