A cage filled with empty-looking oyster shells sits in front of Kellie Fiala on the Canton Waterfront promenade. A crowd of eager high school students from the Baltimore Lab School gather around her as she lifts up a shell for all to see.“Raise your hand if you know what a baby oyster is called?” she asks.“Spat!” yells a student.“Spat. I love it,” Fiala, who works on oyster restoration with the Chesapeake Bay Foundation, nods enthusiastically as she continues. “So there are thousands of spat — baby oysters — on these oyster shells.”Read more (and listen) at WYPR.