So What do the Herring Eat?

We don't fully understand how the herring know when and where to go each year.  However, when they get to Middle Pond and Mystic Lake, they are obviously tired and hungry.

So what are they eating this time of year?

Zooplankton!  More specifically, a type of copepod.  Here's a microscope picture of an actual copepod currently living in Mystic Lake.  

Microcyclops Rubellus