Researchers have found that artificial lights can increase nocturnal predatory behavior on coral reefs.
The research was published in Global Change Biology and is a result of a multinational study with participants from the UK, France, Chile and French Polynesia.
The team used special infrared cameras to monitor reef activity at night. This gave the team an accurate view of reef activity since fish can not see infrared light.
The team found that reefs lit by artificial light had many more fish species present. As a result, those reefs had much higher levels of predatory behavior as the fish remained active.
According to Dr. Emma Weschke, the study lead author from the University of Bristol’s School of Biological Sciences:
“When the sun sets, coral reefs undergo a dramatic transformation. The vibrant fish we see in the day retreat to sleep among the corals and elusive nocturnal species emerge from caves and cervices in pursuit of prey. Many of the species detected on artificially lit reefs were not nocturnal fish, but those that are only usually active during the day. Finding that light pollution can cause fish to stay awake later than usual is concerning because sleep—like for us—is likely essential for regenerating energy and maintaining fitness.”
While the study’s senior author, who is also from The University of Bristol, Professor Andy Radford, stated:
“The night usually brings a veil of darkness that allows marine life to hide from nocturnal predators. But artificial light generated by human activities exposes coral reef inhabitants to unexpected danger. Artificial light makes it much easier for predators to locate and capture prey, reducing their foraging effort. Which is why we think that greater numbers are being attracted to artificially illuminated coral reefs at night.”
