Scuba-Diving Tourists Cause Hidden Damage to Coral Reefs, New Study Warns

Wednesday, May 27, 2026

A University of Sydney study found that scuba-diving tourism in Southeast Asia is causing frequent and often unintentional damage to coral reefs, with divers making nearly 5,000 reef contacts that harmed the fragile ecosystems. The research highlights discrepancies between divers’ perceived and actual behaviors and calls for improved education and stricter industry standards to protect these vulnerable marine environments.

A new study has found that scuba-diving tourism is causing significant, often unintentional, damage to coral reefs in popular destinations across Southeast Asia. Researchers from the University of Sydney examined diver behavior at key sites in the Philippines and Indonesia, including Bali, uncovering evidence that these activities, often promoted as environmentally sustainable, may in fact be harming fragile marine ecosystems.

The research team conducted over 300 hours of underwater observation, tracking the actions of more than 700 scuba divers. They documented nearly 5,000 instances of reef contact involving 411 individual divers. Approximately 41 percent of these contacts resulted in observable harm to the coral, such as physical breakage or sediment disturbances that can suffocate reef life.

Dr. Bing Lin, lead author of the study published in Conservation Letters, emphasized that much of the damage was not intentional. “Many divers believe they are careful and low impact, but our data shows a consistent mismatch between perception and behavior,” he said. The study revealed that about 75 percent of divers rated their reef contact avoidance skills as above average compared to others, illustrating a common psychological bias known as “illusory superiority.” In reality, divers made contact with coral nearly five times more often than they estimated.

Further analysis pointed to specific factors that increased reef damage. The use of underwater cameras and wildlife encounters were linked with higher rates of contact. When marine animals were present, intentional contact rose by 220 percent, unintentional contact by 85 percent, and damaging contacts by 106 percent, often as divers adjusted their positions or approached animals too closely.

Dr. Lin highlighted the importance of tourism to coastal economies, including those connected to Australia. However, he warned that without improvements in diver education, behavior, and industry standards, the growing popularity of scuba diving could threaten the ecosystems that support it. “Divers need to understand that they are a part of the problem before we can convince them to become a part of the solution,” he stated.

The findings underscore the need for enhanced training and stricter guidelines within the dive tourism sector to mitigate the environmental impact and preserve coral reefs, which are already vulnerable due to climate change and other stressors.