ROME — Italy’s cruise liner tragedy turned into an environmental crisis Monday, as rough seas battering the stricken mega-ship raised fears that fuel might leak into pristine waters off Tuscany that are part of a protected sanctuary for dolphins, porpoises and whales.

The ship’s owner accused the jailed captain of causing the wreck that left at least six dead and 29 missing, saying he made an “unapproved, unauthorized maneuver” to divert the vessel from its programmed course.

Earlier, authorities had said 16 people were missing. But an Italian Coast Guard official, Marco Brusco, said late Monday that 25 passengers and four crew members were unaccounted for three days after the Costa Concordia struck a reef and capsized off the coast of the tiny island of Giglio.

He didn’t explain the jump, but indicated 10 of the missing are Germans. Two Americans are also among the missing.

Brusco said there was still “a glimmer of hope” there could be survivors on parts of the vast cruise liner that have yet to be searched. The last survivor, a crewman who had broken his leg, was rescued on Sunday.

Waters that had remained calm for the first days of the rescue turned choppy Monday, shifting the wreckage and raising fears that any further movement could cause some of the 500,000 gallons of fuel on board to leak into the waters off Giglio, which are popular with scuba divers and form part of the protected Tuscan archipelago. Rescue operations were suspended for several hours because of the rough seas.

Italy’s environmental minister raised the alarm about a potential environmental catastrophe. “At the moment there haven’t been any fuel leaks, but we have to intervene quickly,” the minister, Corrado Clini, told RAI state radio.