I love sciences, especially biology. I am an unashamed biology nerd. I think nothing brings that home more than this picture I took of a plankton net hanging up to dry in my shower. Currently, I work with larval forms and a plankton net is en essential tool for catching my animals. Here are pictures of some of the things I've caught:
Tunicate larva (aka sea squirts)
Bryozoan larva (aka moss animal)
There are a lot of things that live floating around in the water, that many people don't get to see because they don't have a microscope (or a plankton net). But that should not discourage those who want to explore their world. There are ways to make plankton nets out of nylon stockings and "children's" scopes that are cheap, but have pretty decent magnification power. If you're not a do-it-yourself type, visit your local aquarium. Often those that are close to a body of water (fresh or marine) will have a plankton life exhibit. Even if they are not close to water, they might show their planktonic cultures which they feed to their fish.