New study illustrates the physics behind great white shark attacks on seals

Dec 09, 2011
A new study examining the complex and dynamic interactions between white sharks and Cape fur seals in False Bay, South Africa in Marine Biology Review offers new insights on the physical conditions and biological factors underlying predator-prey interactions in the marine environment. Credit: Neil Hammerschlag/http://www.neilhammer.com

A new study examining the complex and dynamic interactions between white sharks and Cape fur seals in False Bay, South Africa, offers new insights on the physical conditions and biological factors underlying predator-prey interactions in the marine environment.

University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science assistant professor Dr. Neil Hammerschlag, and a colleague from the University of British Columbia, describe how sharks are camouflaged as they stalk their prey from below. Low-light conditions, from the optical scattering of light through water, along with a shark's dark grey back and the dimly light rocky reef habitat allow sharks to remain undetected by seals swimming at the water's surface.

"Animal hunting in the ocean is rarely observed by humans," said Hammerschalg, director of the RJ Dunlap Marine Conservation Program at UM. "The high frequency of attacks by white sharks on seals at our study site in South Africa provides a very unique opportunity to uncover new insights about predator-prey relationships."

Sharks typically search, stalk and strike their prey from below. The vast majority of predatory strikes by sharks and Cape fur seals occur against small groups of young-of-the-year seals. Predatory activity by sharks is most intense within two hours of sunrise and quickly decreases as light penetration in the increases.

"Stealth and ambush are key elements in the white shark's predatory strategy," said Hammerschlag.

Cape fur seals also have unique techniques to detect, avoid, outmaneuver and in some cases injure the in order to avoid predation by .

According to the authors, if a seal is not disabled during the shark's initial shark, the small seal can use its highly maneuverable body to leap away from the shark's jaws to evade a second strike.

Explore further: Male monkey filmed caring for dying mate (w/ Video)

More information: The study, titled "Marine predator-prey contests: Ambush and speed versus vigilance and agility," was published in the Nov. 30 online edition of the journal Marine Biology Research.

add to favorites email to friend print save as pdf

Related Stories

Scientists track great hammerhead shark migration

Feb 28, 2011

A study led by scientists at the University of Miami (UM) Rosenstiel School of Marine & Atmospheric Science details the first scientific research to successfully track a great hammerhead shark using satellite ...

Conservation dollars and sense

Jun 27, 2011

Shark populations over the last 50 years have decreased dramatically. From habitat degradation to overfishing and finning, human activities have affected their populations and made certain species all but ...

Great white sharks tagged for first time off Mass.

Sep 06, 2009

(AP) -- Massachusetts officials are using high-tech tags to track the movements of two great white sharks near Cape Cod - the first time the fearsome fish have ever been tagged in the Atlantic Ocean.

Teenage great white sharks are awkward biters

Dec 02, 2010

The jaws of adolescent great white sharks may be too weak to capture and kill large marine mammals, according to a new study published in the Journal of Biomechanics by an international team of scientists.

Recommended for you

Male monkey filmed caring for dying mate (w/ Video)

Apr 18, 2014

(Phys.org) —The incident was captured by Dr Bruna Bezerra and colleagues in the Atlantic Forest in the Northeast of Brazil.  Dr Bezerra is a Research Associate at the University of Bristol and a Professor ...

Orchid named after UC Riverside researcher

Apr 17, 2014

One day about eight years ago, Katia Silvera, a postdoctoral scholar at the University of California, Riverside, and her father were on a field trip in a mountainous area in central Panama when they stumbled ...

In sex-reversed cave insects, females have the penises

Apr 17, 2014

Researchers reporting in the Cell Press journal Current Biology on April 17 have discovered little-known cave insects with rather novel sex lives. The Brazilian insects, which represent four distinct but re ...

Fear of the cuckoo mafia

Apr 17, 2014

If a restaurant owner fails to pay the protection money demanded of him, he can expect his premises to be trashed. Warnings like these are seldom required, however, as fear of the consequences is enough to ...

User comments : 0

More news stories

Cancer stem cells linked to drug resistance

Most drugs used to treat lung, breast and pancreatic cancers also promote drug-resistance and ultimately spur tumor growth. Researchers at the University of California, San Diego School of Medicine have discovered ...