Guardian: Tough new restrictions on the number of people visiting Antarctica are to be implemented as the volume of visitors to the White Continent continues to soar. Cruise ships carrying more than 500 passengers will be prohibited from landing anyone. Only 100 visitors are to be allowed on shore at any given time, in an attempt to prevent damage to the region’s unique ecosystem. The limits, agreed by the 28 countries that have signed the Antarctic treaty, including the UK, are to be …