The one in the center is a Common Merganser (Mergusmerganser). Unfortunately, I’m not very good at identifying female waterfowl, so sorry, I can’t help you with the rest.
The black and white one in the middle is a goosander (Mergus merganser) while the duck diagonally above (with the brown stripe near the eye is most likely a white-headed duck (Oxyura leucocephala).
A bit old, but why not comment? The white bird in the center is a male Scaly Sided Merganser. The large grey one to the left of him is a female Canvasback. The brownish one directly below her with its head in the water is a Chestnut Teal drake.
I agree, female white headed duck is the uppermost bird on the water. I think the other duck pictured on the water is either a female northern pintail, or mellers duck. Also the half a bird on the water far right is a ringed teal drake. The rest on land are all either Chiloe Wigeons or Pochards of some sort.
