A recent paper in Behavioral Ecology indicates that noise pollution may confuse the recruitment of larval reef fish to safe habitats.
Coral reefs set up and interesting quandary for larval-stage reef inhabitants. When they are tiny, their “mother reef” is actually a dangerous place – given the billions of feeding mouths that constitute a healthy reef habitat. To avoid becoming feed-stock for the larger life in the reef, many animals disperse out to sea in their larval state to live in the relative safety of open waters. But once they become large enough to benefit from the reef, they will recruit back to where they were born.
It has been known for some time that larval reef animals imprint on the sounds of their “mother reef” in order to find it once they are ready. The research in the Behavioral Ecology paper demonstrated that larval animals will imprint on artificial sounds as well as natural sounds. The implication here is that if larval fish imprint on the sound of a ship or pile driving, for example, they might seek their final home in the shipping lanes or at a marine construction site as opposed to the natural reef habitat.
A lay language discussion of the paper was recently published in Science.
To paraphrase the tag-line in Peter Benchley’s Jaws “…just when you thought it was safe to head back to the reef…”