I just looked on the page for the aquarium at the DMR and They do have a volunteer position for someone your age: Junior Docent Volunteers. You probably wouldn't be able to do it this summer, but if not you could apply for next year.
http://www.state.me.us/dmr/rm/aquarium/jobs.htm
I don't think they have any cephs there. It's mostly about coastal Maine stuff, so heavy on the lobsters. But they are pretty neat too. And fun to poke at right after they've molted, all squishy and too weak to pinch.
erin