For the study, the researchers surveyed more than 2,500 reefs around the world and identified 15 reefs that were surprisingly healthy, despite living closer to large human populations or unfavorable environmental conditions. The findings of the study are published in journal Nature.
Josh Cinner, a professor at James Cook University in Australia, said that these bright spots had far more fish than the researchers could expect.
Besides the 15 bright spots, Cinner and his colleagues found 35 "dark spots," areas with fewer fish than the researchers would have anticipated.
"We wanted to know why these reefs could punch above their weight, so to speak, and whether there are lessons we can learn about how to avoid the degradation often associated with overfishing," Cinner, the study's lead author, said in a statement.
Coral reefs provide habitat and food for several species but their population growth is under threat around the world due to overfishing and destructive fishing practices such as dragging large nets across the ocean floor. Climate change also threatens the reefs with increased coral bleaching and more severe cyclones.
These bright spots are typically found in the Pacific Ocean and they included reefs in the Solomon Islands, parts of Indonesia, Papua New Guinea and Kiribati. In these countries, people had strong cultural institutions attached to the reefs.
The environmental conditions were also found to be favorable in bright spots. The researchers said that more studies are needed to find out the exact reasons why the conditions at bright spots are better than other reefs in similar conditions.