"It's probably not a very healthy ecosystem.  The lake," Ethan shrugged.  "There could, I suppose, but it's not a natural lake.  People have probably released fish into it for fun or something, but the question is whether they'd survive."  He'd not thought much about the fish in the lake, though he was mildly concerned by it.  There was no place for the water to flow, so it was just stagnating there, for as long as DHHW has been here.  What kinds of nasty creatures would that foster?