Questions are based on the following passage.
The huge growth of global "ecotourism" industry is becoming an increasing concern for con servationists with mounting evidence that many wild species do not respond well to contact with human beings. Over exposure to tourists has been linked to stress, abnormal behaviour and adverse health effects in species such as polar bears, dolphins and gorillas, says a report in New Scientist.
"While regulated ecotourism can help conservation efforts by encouraging people to manage endangered species and their habitats, many projects are poorly designed and unregulated," it says.
"Many ecotourism projects are unaudited, unauthorized and merely hint they are based on environmentally friendly policies and operations."
Ecotourism is growing by 10 to 30 percent a year and an estimated 20 percent of tourists are thought to visit a conservation-based project. Philip Seddon, of the University of Otago in New Zealand, said that although most tourist projects conformed to basic guidelines on land use and not scaring wildlife, their full impact was rarely considered.
"Transmission of disease to wildlife or subtle changes to wildlife health through disturbance of daily routines or increased stress levels may translate to lowered survival and breeding" he said. Re- search at the University of Auckland has shown that dolphins become restless and overactive when many tourist boats are present. When three or more boats are near, the dolphins rest for 0.5 percent of the time, compared with 68 percent when they are accompanied by a single boat. The findings are backed up by studies of dolphins in Britain. Researchers at the University of Manitoba in Canada have found that male polar bears were easily disturbed by tourist vehicles, with a possible effect on their heart rate and metabolism. That could reduce body fat levels and fitness, which are critical for survival.
In Africa, gorillas have picked up parasites introduced to their habitat by tourists and mongooses have caught lung diseases from human beings. Experts said that the answer to the problems was better regulation and supervision of ecotourism. The Galapagos Islands, where visitor numbers are strictly controlled, is a good model.
What can we know from the first paragraph?