FIFTY YEARS AGO, representatives of 12 nations gathered in Washington to sign a treaty designating all land and ice shelves south of 60 degrees South Latitude as a nuclear-free zone dedicated to the pursuit of science and other peaceful purposes. Signed on Dec. 1, 1959, the Antarctic Treaty came into force on June 23, 1961. The 12 original signatories — Argentina, Australia, Belgium, Chile, France, Japan, New Zealand, Norway, South Africa, the Soviet Union, the United Kingdom and the United States — were those nations active in Antarctica during the International Geophysical Year of 1957-58. The treaty now has 47 parties, 28 of which have consultative (or voting) status.

The treaty mandates the free pursuit of scientific research and the free exchange of information and personnel. One of the most significant discoveries to come out of the research conducted in Antarctica is the existence of the ozone hole, first documented by the British Antarctic Survey in 1985. It led to a permanent ban on chlorofluorocarbons (CFCs), once used in refrigerants and aerosol propellants. Over the years, several additional agreements were adopted by the treaty parties to address issues related to resource and wildlife conservation. The most recent of these, the Protocol on Environmental Protection, was adopted in 1991 and entered into force in 1998. Together, the treaty and associated agreements form the complex legal framework known as the Antarctic Treaty System.

While the treaty’s success and durability are a cause for celebration, some significant challenges have emerged over the past couple of decades. One of these is the effective management of tourism and its growth.

Antarctic tourism dates back to the late 1950s, when Chile and Argentina took 500 fare-paying passengers to the South Shetland Islands aboard a naval transport. The current model of expedition cruising came into being when Swedish explorer Lars-Eric Lindblad led the first such tour to Antarctica, in 1966. In 1969, Lindblad commissioned the world’s first expedition ship, the Lindblad Explorer, specifically designed to take tourists to the Antarctic. Despite an ice-strengthened hull — in November of 2007, the Explorer became the first cruise ship to sink off the coast of Antarctica. Fortunately, all 154 passengers and crew were rescued, thanks to a prompt response by other cruise ships in the area and favorable weather conditions.

Tourists visiting the White Continent travel mainly by ship and mostly to the Antarctic Peninsula, the area closest to South America. A small number of over-flights have been offered in recent years, along with some inland skiing and trekking expeditions. While fewer than 1,000 tourists a year on average ventured to Antarctica through the late 1980s, the number expanded over the following decades to around 46,000, with 32,000 setting foot on land, during the 2007-2008 season. This number dropped 17 percent during the recently concluded season to 38,200, with about 27,000 on land, largely because of economic factors. With restrictions on heavy fuels in Antarctic waters scheduled to take effect in 2011, ship-based tourism is expected to contract even further. Nevertheless, Antarctica is likely to remain a popular tourist destination, although very much a niche market.

In response to the growth in Antarctic tourism and the need to ensure safe and environmentally responsible travel, the International Association of Antarctica Tour Operators (IAATO) was formed in 1991. Currently based in Providence, IAATO has 109 members worldwide and includes virtually all Antarctic cruise operators with the exception of a few private yachts.

The prompt and coordinated response of IAATO members to the Explorer sinking was a key factor in the success of the rescue operation. Under the IAATO bylaws, vessels carrying more than 500 passengers are not permitted to make landings, and vessels making landings are not allowed more than 100 passengers ashore at the same time. These IAATO regulations were made binding at this year’s Antarctic Treaty Consultative Meeting in Baltimore and are now subject to ratification by the treaty’s 28 consultative parties, including the United States.

Passenger welfare and environmental protection are by far the most important issues facing the Antarctic tourism industry today. Recommendations to enhance marine safety topped the agenda at IAATO’s 20th annual meeting, which happened in Providence in June. Members also passed a motion recognizing climate change as a significant threat to the Antarctic environment and formed a working group to explore ways to reduce tourism’s carbon footprint.

While the challenges are substantial, there are also significant benefits being derived from tourism operations in the Antarctic. One is the information provided in the post-visit reports required of tour operators on conditions observed at landing sites, such as evidence of “high-mortality events” among wildlife. This information is submitted to IAATO and shared with the appropriate authorities. Tourist vessels also transport scores of scientists each year to stations operated by treaty parties, and both passengers and tour operators contribute generously to Antarctic-related causes. In the 2007-2008 season alone, these contributions totaled over $500,000.

Tourism has helped raise public awareness and motivate behavioral change regarding the White Continent, and has created a growing number of advocates and ambassadors on its behalf. As Lars-Eric Lindblad, father of Antarctic tourism, once said, “You can’t protect what you don’t know.”

Steve Wellmeier is executive director of the Providence-based International Association of Antarctica Tour Operators; Jo Yellis is a freelance travel writer living in Newport and former executive director of Horizon International, a not-for-profit environmental communications organization.