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

December 9, 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: Great white sharks hunt just like Hannibal Lecter

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.

Related Stories

Great white sharks tagged for first time off Mass.

September 6, 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

December 2, 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.

Scientists track great hammerhead shark migration

February 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 tag technology.

Conservation dollars and sense

June 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 disappear.

Recommended for you

Genomes uncover life's early history

August 24, 2015

A University of Manchester scientist is part of a team which has carried out one of the biggest ever analyses of genomes on life of all forms.

Rare nautilus sighted for the first time in three decades

August 25, 2015

In early August, biologist Peter Ward returned from the South Pacific with news that he encountered an old friend, one he hadn't seen in over three decades. The University of Washington professor had seen what he considers ...

Study shows female frogs susceptible to 'decoy effect'

August 28, 2015

(Phys.org)—A pair of researchers has found that female túngaras, frogs that live in parts of Mexico and Central and South America, appear to be susceptible to the "decoy effect." In their paper published in the journal ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.