Here you have a marine food web graphic representation using some of my drawings. Feel free to use it for teaching, although I would ask to mention the source and authorship.
The little blurry dots represent virus and bacteria. Given they feed at all levels of the food web I positioned them all around. I hope you like it. Phytoplankton are at the base of the food web, together with some small mixotrophs. Both are grazed by larger heterotrophic and mixotrophic protists, such as ciliates and dinoflagellates, but also by appendicularians. Copepods are one step above; although they graze on both large and small protists I kept them on an upper position on the food web. Above them, we have krill, whales and jellyfish. On top of that we have fish, and at the highest level of the food web we found sharks, although humans would be a perhaps more realistic end point for the food web.
Plankton Ocean 