As an industry, it often competes for prime real estate and juxtaposes visitors with different cultural practices and values to host communities, with consequent negative influences. Their economies and progress in development have been the subject of intense scrutiny, as a result of limitations in topographic character; vulnerability to natural disasters, climate changes and related impacts; threats to biological diversity, especially in coastal and marine areas; consumption of scarce natural resources; declining traditional productive sectors; poverty; and their reliance on the travel and tourism industry for economic performance. Large island nations comprising Papua New Guinea, Cuba, Hispaniola (Haiti and the Dominican Republic), Guinea Bissau and those located in Central/South America (Suriname, Guyana, Belize) make up the SIDS grouping with geographic areas in excess of 25,000 km2. There is significant variability in GDP per capita, as indicated in figure 8.3, with many of the more developed tourist economies such as Aruba, Singapore, US Virgin Islands (USVI) and the Bahamas, showing higher levels of prosperity.