Ghouls, goblins and a few superheroes took part in a cleanup event at Levi Carter Park Sunday.
The Henry Doorly Zoo and Aquarium hosted the event which featured a costume contest and prizes for the person who picked up the most trash.
It also featured hands-on science for the kids. Zoo staff gave lessons on freshwater ecosystems and they test water for chemicals.
"We're really concerned about the watershed in general," said conservation education coordinator Jake Wiebe. "Watershed being anywhere that water flows into and runs off into being so close the Missouri that will connect over to the to the Mississippi eventually."
The zoo partnered with Keep Omaha Beautiful to put on the event.