The measurement index goes from 0 to 5, with 0 being the worst and 5 being the best. Labels and certification
Over 50 ecolabels on tourism exist. These include (but are not limited to):

Austrian Ecolabel for Tourism
Asian Ecotourism Standard for Accommodations (AESA)
Eco-certification Malta
EarthCheck Australia
Ecotourism Australia
Ecotourism Ireland
Ecotourism Kenya
European Ecotourism Labelling Standard (EETLS)
Korean Ecotourism Standard

Guidelines and education
An environmental protection strategy must address the issue of ecotourists removed from the cause-and-effect of their actions on the environment. More initiatives should be carried out to improve their awareness, sensitize them to environmental issues, and care about the places they visit.Tour guides are an obvious and direct medium to communicate awareness. With the confidence of ecotourists and intimate knowledge of the environment, tour guides can actively discuss conservation issues. Informing ecotourists about how their actions on the trip can negatively impact their environment and the local people. A tour guide training program in Costa Ricas Tortuguero National Park has helped mitigate negative environmental impacts by providing information and regulating tourists on the parks beaches used by nesting endangered sea turtles. Small scale, slow growth and local control
The underdevelopment theory of tourism describes a new form of imperialism by multinational corporations that control ecotourism resources. These corporations finance and profit from the development of large scale ecotourism that causes excessive environmental degradation, loss of traditional culture and way of life, and exploitation of local labor.
They conclude that ecotourism works best to conserve predators when the tourism industry is supported both politically and by the public, and when it is monitored and controlled at local, national, and international levels. Regulation and accreditation
Because the regulations of ecotourism may be poorly implemented, ecologically destructive greenwashed operations like underwater hotels, helicopter tours, and wildlife theme parks can be categorized as ecotourism along with canoeing, camping, photography, and wildlife observation. The failure to acknowledge responsible, low-impact ecotourism puts legitimate ecotourism companies at a competitive disadvantage. Management strategies to mitigate destructive operations include but are not limited to establishing a carrying capacity, site hardening, sustainable design, visitation quotas, fees, access restrictions, and visitor education. Many environmentalists have argued for a global standard that can be used for certification, differentiating ecotourism companies based on their level of environmental commitment, creating a standard to follow. A national or international regulatory board would enforce accreditation procedures, with representation from various groups including governments, hotels, tour operators, travel agents, guides, airlines, local authorities, conservation organizations, and non-governmental organizations. The decisions of the board would be sanctioned by governments, so that non-compliant companies would be legally required to disassociate themselves from the use of the ecotourism brand. In 1998, Crinion suggested a Green Stars System, based on criteria including a management plan, benefit for the local community, small group interaction, education value and staff training. Ecotourists who consider their choices would be confident of a genuine ecotourism experience when they see the higher star rating.