Build a trash collector for lakes and rivers

What if learners fixed and modified a small paddle boat to serve as a trash collector?  Engineering students could create a collector system that would scoop up trash and plastic bottles floating on the surface.  Learners could go for a leisurely stroll around the edge the lake and clean up the water at the same time!  An interesting contraption was created by students in Colorado to clean up rivers and creeks, what solution will your learners come up with?