The growing amount of human noise pollution in the ocean could lead fish away from good habitat and off to their death, according to new research from a UK-led team working on the Great Barrier Reef.
After developing for weeks at sea, baby tropical fish rely on natural noises to find the coral reefs where they can survive and thrive. However, the researchers found that short exposure to artificial noise makes fish become attracted to inappropriate sounds.
In earlier research, Dr Steve Simpson, Senior Researcher in the University of Bristol's School of Biological Sciences discovered that baby reef fish use sounds made by fish, shrimps and sea urchins as a cue to find coral reefs. With human noise pollution from ships, wind farms and oil prospecting on the increase, he is now concerned that this crucial behaviour is coming under threat.
He said: "When only a few weeks old, baby reef fish face a monumental challenge in locating and choosing suitable habitat. Reef noise gives them vital information, but if they can learn, remember and become attracted towards the wrong sounds, we might be leading them in all the wrong directions."
Using underwater nocturnal light traps, Dr Simpson and his team collected baby damselfish as they were returning to coral reefs. The fish were then put into tanks with underwater speakers playing natural reef noise or a synthesised mix of pure tones. The next night the fish were put into specially designed choice chambers (long tubes with contrasting conditions at each end in which fish can move freely towards the end they prefer) with natural or artificial sounds playing. All the fish liked the reef noise, but only the fish that had experienced the tone mix swam towards it, the others were repelled by it.
Dr Simpson said: "This result shows that fish can learn a new sound and remember it hours later, debunking the 3-second memory myth."
His collaborator, Dr Mark Meekan added
|Contact: Caroline Clancy|
University of Bristol