Antarctica, the world's last pristine wilderness, is particularly vulnerable to human presence. Not only must life in the Antarctic contend with one of the harshest environments on earth, but an ever-increasing human presence is adding a greater amount of stress to the fragile and unique ecosystem. Recognising this urgency Visitor Guidelines have been adopted by all of the US ship tour operators to be made available to all visitors travelling with them to Antarctica to protect and preserve the continent and to leave it unimpaired for future generations.