Featured Research

from universities, journals, and other organizations

The physics behind great white shark attacks on seals

Date:
December 16, 2011
Source:
University of Miami Rosenstiel School of Marine & Atmospheric Science
Summary:
A new study examines the complex and dynamic interactions between white sharks and Cape fur seals in False Bay, South Africa; Offers new insights on physical and biological factors underlying predator-prey interactions in marine environment.

Scientists studied how sharks are camouflaged as they stalk their prey from below.
Credit: N. Hammerschlag

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 water column 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 white shark in order to avoid predation by sharks.

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.

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. Hammerschlag's co-author is the late Dr. R. Aiden Martin.


Story Source:

The above story is based on materials provided by University of Miami Rosenstiel School of Marine & Atmospheric Science. Note: Materials may be edited for content and length.


Journal Reference:

  1. R. Aidan Martin, Neil Hammerschlag. Marine predator–prey contests: Ambush and speed versus vigilance and agility. Marine Biology Research, 2012; 8 (1): 90 DOI: 10.1080/17451000.2011.614255

Cite This Page:

University of Miami Rosenstiel School of Marine & Atmospheric Science. "The physics behind great white shark attacks on seals." ScienceDaily. ScienceDaily, 16 December 2011. <www.sciencedaily.com/releases/2011/12/111209105326.htm>.
University of Miami Rosenstiel School of Marine & Atmospheric Science. (2011, December 16). The physics behind great white shark attacks on seals. ScienceDaily. Retrieved September 21, 2014 from www.sciencedaily.com/releases/2011/12/111209105326.htm
University of Miami Rosenstiel School of Marine & Atmospheric Science. "The physics behind great white shark attacks on seals." ScienceDaily. www.sciencedaily.com/releases/2011/12/111209105326.htm (accessed September 21, 2014).

Share This



More Plants & Animals News

Sunday, September 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: San Diego Zoo Welcomes Cheetah Cubs

Raw: San Diego Zoo Welcomes Cheetah Cubs

AP (Sep. 20, 2014) The San Diego Zoo has welcomed two Cheetah cubs to its Safari Park. The nearly three-week-old female cubs are being hand fed and are receiving around the clock care. (Sept. 20) Video provided by AP
Powered by NewsLook.com
Chocolate Museum Opens in Brussels

Chocolate Museum Opens in Brussels

AFP (Sep. 19, 2014) Considered a "national heritage" in Belgium, chocolate now has a new museum in Brussels. In a former chocolate factory, visitors to the permanent exhibition spaces, workshops and tastings can discover derivatives of the cocoa bean. Duration: 01:00 Video provided by AFP
Powered by NewsLook.com
Could Grief Affect The Immune Systems Of Senior Citizens?

Could Grief Affect The Immune Systems Of Senior Citizens?

Newsy (Sep. 19, 2014) The study found elderly people are much more likely to become susceptible to infection than younger adults going though a similar situation. Video provided by Newsy
Powered by NewsLook.com
Jury Delivers Verdict in Salmonella Trial

Jury Delivers Verdict in Salmonella Trial

AP (Sep. 19, 2014) A federal jury has convicted three people in connection with an outbreak of salmonella poisoning five years ago that sickened hundreds of people and was linked to a number of deaths. (Sept. 19) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins