Did you know that if you hold up a regular digital camera up to the eyepiece of a microscope you can take a great picture of a magnified slide! I didn’t. And I really didn’t think it would work when I tried it, but the results are remarkable. With a somewhat steady hand you can also make decent animations.
I’ve never been very good at identifying things (I’m a lumper not a splitter) so all I think I can say for sure is that there are algae and protozoans in the picture. BiologyCorner has a nice identification guide for organisms usually found in ponds, which is part of one of their lessons, Biodiversity of Ponds.