I'm no pond expert, so this is just me as 'keyboard consultant' but couple things-
Are you saying the pond you are working on is the THIRD in line, as in the last down-stream one? That stuff from the creek and the other 2 ponds flow into yours? That will probably end up messing up your long term solution, as whatever is in those upper ponds will flow into yours.
Where else does that creek wander through upstream from you? Again, no expert, but that water quality reminds me of creeks from back in Wisconsin that wandered through farms with dairy cattle - that is, that algae there looks "powered" by nitrogen runoff - from cow poop or field fertilizer. I would want to think about what level of exposure you're comfortable with if that's the case.
I agree with other answer about how great that stuff would be to gather and add to compost or garden.
Perhaps, if I'm in the ballpark about the nitrogen content, you could plant something - at the upper end edge - that really sucks up nitrogen. Something you'd like, and could use. I don't know what that would be, but maybe bamboo?
What sort of wildlife is in the pond now? Are there fish? frogs? how deep is it?