Sharks can predict weather


Don t trust the weather reports on television?

Then start looking to the seas - a study in Scotland has shown that sharks have a well developed ability to sense changes in pressure.

The PhD study conducted by Lauren Smith at the University of Aberdeen was prompted by a study by Michelle Heupel, a biologist from Sarasota who speculated that sharks could sense changes in barometric pressure after she observed a group of juvenile black tip sharks, Carcharhinus limbatus, leave shallow water for deeper water as Hurricane Gabrielle approached in 2001.

The same behaviour was observed again in 2004 when Hurricane Charley hit the coast of Florida and a different group of monitored sharks swam out to deeper waters in the Gulf of Mexico.

PhD student Lauren Smith with a Lesser spotted dogfish.

Smith took this information and studied the effects of pressure on Lemon sharks Negaprion brevirostris in the Bahamas.

The juvenile sharks were observed using tags that logged position, temperature and pressure. Using GPS technology she was then able to track the movement of the sharks in response to changes in the weather.

In addition, she took a group of Lesser spotted dogfish Scyliorhinus canicula and placed them under varying simulated weather conditions at the National Hyperbaric Centre in Aberdeen. These conditions mimicked the changes occurring naturally in and above the ocean due to weather fronts.

Smith s supervisor Dr Peter Fraser has recently discovered a sense organ known as the vestibular system which detects changes in hydrostatic pressure in vertebrates. This organ detects compression of a large number of tiny thread like hairs which are paired with cells which detect movement of any kind. The message is then processed by the brain or nervous system.

Smith s PhD will be completed later this year and she hopes to publish a number of papers with her findings.

"Who can say if this could lead to sharks predicting weather fronts, there's so much more we need to understand. But it certainly opens the way to more research." Ms Smith said.