Motorboat noise poses threat to clownfish: Study

By Burak Bir

ANKARA (AA) - Amid the almost unnatural quiet from lockdowns due to coronavirus, scientists have found yet another reminder of how much harm human activity can do to wildlife.

Hormonal changes caused by motorboat noise make clownfish stressed, aggressive, and often lead them to hide and skip their meals, a new study has found.

A team of scientists from France, Chile, and the U.K., which worked on the reefs around Moorea Island in French Polynesia, found that anemonefish or clownfish are highly affected by motorboat noise, a source of their unusual behavior.

According to the study published by Environmental Pollution journal, and reported on phys.org on Thursday, "high cortisol levels after two days of exposure suggest that clownfish become chronically stressed by motorboat noise. This compromises the stress response system, leaving clownfish unable to mount appropriate responses to further stressful events."

Researchers found that since clownfish were unable to respond properly to a second stress source, they are at huge risk from predators and climate change.

"Now we know that hormonal responses are the mechanisms driving behavioral changes to motorboat noise, they can be a useful tool in regulation," another scientist said in the study.

"We might be able to predict the duration and/or interval times of motorboat noise exposure that allow individuals to return to normal behavior."

Clownfish are usually red, orange, or yellow with white stripes, and live in warm or tropical seas.

They are mainly found around certain kinds of anemones, a group of marine, predatory animals.