The Scent Of Home

Human beings rely exclusively on landmarks and other visual cues in order to navigate their way back home, but when you’re out in the open ocean and miles from safety, you sometimes have to rely on your nose instead.

A recent scientific study conducted at the Great Barrier Reef in Australia has proven that some of the reef’s smallest and most vulnerable inhabitants - fish larvae - can smell the presence of coral reefs from as far as several kilometres offshore, and use this odour to find a home. Cardinalfish larvae, for example, were shown to start zigzagging in response to the smell of their home reef, using the odour cues to orient themselves, while Damselfish larvae would slow down, align themselves along the shoreline and head due west. In effect, the reef’s odour acts as a “wake-up call” that tells the fish larvae to modify their activity for directions towards the reef.

But this new fact is far from simply an interesting bit of trivia as it reveals in even greater relief the huge impact that human activities can have on natural ecosystems. By disrupting the smells emitted by the reefs, they can unwittingly prevent fish larvae from orienting back home and therefore cause them to stay out at sea and become easy prey…