When the COVID-19 pandemic nearly shut down tourism in Hawaii, changes started happening under the near-shore ocean: The water got cleaner and marine life more abundant when people were removed.

An early study of Hanauma Bay reached this conclusion. Now a new study of Molokini islet off Maui, published in the PLOS One scientific journal, bolsters this view. It suggested that the absence of snorkelers increased the number of fish in the protected area, including predators like omilu. It’s further evidence that snorkeling can’t be considered a benign, eco-friendly activity. It actively changes the environment, and should be managed.