It sure looks like FA (slime algae). I had it pretty good the fisrt year of my pond's renovation and it has slacked off alot since then. Your bloom (green tinge) looks real good! I would not worry too much about it at this point and see what it does. A new pond that deep should not go crazy with FA especially without any fertilizers running into it. I suspect that my first years FA attach was due to clearer waters, minimal blooms, and left over muck left in the pond basin (you just can't get it all out). Your case might just be the early clear waters and nutritious topsoil residuals. At any rate, it's not "bad" algae like the blue/green cynobacteria algae, just the regular ole' FA. You may find that it grows well, dies off, and then floats around the pond with hopefully alot less next year.

Fish on!,
Noel