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PRI's Environmental News Magazine

Science Note - Sharks and Smell

Air Date: Week of February 4, 2011

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A hammerhead shark. (Wikipedia Creative Commons)

Researchers discover that sharks use their nostrils independently of one another to find food. Meghan Miner reports.

Transcript

GELLERMAN: Just ahead – hearing tests - for dolphins - but first, this note on emerging science from Meghan Miner.

[SCIENCE NOTE THEME]

MINER: A state-of-the-art theater with surround sound gives the illusion that audio is just behind you, or to the right, or left. In the grand theater of the ocean, sharks experience surround-smell.

Scientists originally thought sharks used the intensity of smells to locate food. But, because smells don't disperse evenly in water, marine biologists in Florida and Massachusetts wondered if this really was how sharks find their prey.



A hammerhead shark. (Wikipedia Creative Commons)

The researchers set up an experiment where sharks wore headgear that released scents of different concentrations - one nostril at a time. They found that even when an extremely diluted smell was sent to one nostril before a full strength odor was sent to the other - the shark turned in the direction of the nostril that sniffed the smell first.

This showed that sharks use each of their two nostrils independently to pinpoint their food.

The finding may help explain why hammerhead sharks are considered the fastest and often the first sharks to reach prey. Hammerheads have nostrils on either side of their head, increasing the lag time between scents reaching each nostril - making them faster at honing in on dinner. That's this week's Note on Emerging Science. I'm Meghan Miner.

 

Links

Researcher Jayne Gardiner’s website

The article’s abstract/summary in Current Biology

 

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