Traveler’s Note . . .

Carnival Corp. has been subpoenaed by a federal grand jury in Florida to provide documents about environmental practices on its ships. The subpoena suggests that the Miami-based cruise giant, which operates Carnival Cruise Lines and five other lines, could be the target of a continuing pollution investigation similar to one that resulted in a conviction and fine of rival Royal Caribbean. “At present we know very little about why the subpoena came to us,” the company said last week.