Final answer:
The presence of western tourists poses challenges for the Trobriand Islanders, including cultural dominance and environmental issues. Strict management is necessary to address these challenges and safeguard the island's culture and environment.
Step-by-step explanation:
The major challenge facing the Trobriand Islanders today due to the influx of western tourists involves a complex interaction of cultural, economic, and environmental factors. Western tourism brings not only economic benefits but also challenges including cultural erosion, environmental impacts, and resource exploitation. In the case of Tahiti and other island communities, we see the loss of traditional indigenous culture and an increase in environmental pollution due to tourist activity. Places like Rapa Nui faced difficulties with deforestation and resource depletion, as well as cultural changes and collapse post European contact. Some countries, such as Bhutan, have addressed these challenges by implementing strict tourism regulations to preserve their cultural heritage and environmental health.