Featured Research

from universities, journals, and other organizations

Australia has two distinct white shark populations

Date:
June 7, 2012
Source:
ARC Centre of Excellence for Coral Reef Studies
Summary:
A new scientific study has identified two distinct populations of white shark at the east and west of Bass Strait in Australian waters, prompting researchers to suggest the huge fish may need regional conservation plans.

Shark. A new scientific study has identified two distinct populations of white shark at the east and west of Bass Strait in Australian waters, prompting researchers to suggest the huge fish may need regional conservation plans.
Credit: Joshua Haviv / Fotolia

A new scientific study has identified two distinct populations of white shark at the east and west of Bass Strait in Australian waters, prompting researchers to suggest the huge fish may need regional conservation plans.

Published in the journal Marine Ecology Progress Series, the paper is authored by researchers from the ARC Centre of Excellence for Coral Reef Studies, The University of Queensland, CSIRO Wealth from Oceans Flagship and the Department of Agriculture, Fisheries and Forestry (DAFF Queensland).

"The genetic makeup of white sharks west of Bass Strait was different from those on the eastern seaboard of Australia -- despite the lack of any physical barrier between these regions," says Professor John Pandolfi, a Chief Investigator at CoeCRS and UQ.

"This shows that while the sharks can roam around Australia and across ocean basins, they repeatedly return to their home region to breed."

The study examined tissue samples from 97 sharks collected around Australia since 1989 which were caught in beach safety programs, as fishery bycatch and during CSIRO field-research. Its findings are broadly consistent with satellite and acoustic tracking research led by CSIRO's Barry Bruce.

"Our tagging and tracking showed that white sharks travel thousands of kilometres," says Mr Bruce. "But sharks tagged and tracked off eastern Australia did not go west of Bass Strait, and sharks tagged off Western and South Australia rarely went east. When they did -- they often returned, so we started to wonder whether there was more than one breeding population.

"Now we know that while white sharks across Australia can mix, the intriguing thing is that they seem to return to either east or western regions to breed."

The study builds on results by other international research teams that have identified separate genetic populations of white sharks across ocean basins. However, this is the first time such differences have been found at the regional scale.

White shark numbers declined in the 20th century and the species is now protected in South Africa, the United States, Australia, New Zealand, Malta, Namibia, throughout the Mediterranean Sea and globally under the Convention on International Trade in Endangered Species (CITES).

However, a lack of information on abundance, genetic diversity, reproductive behaviour and population structure has prevented accurate assessment of the effectiveness of white shark conservation programs, including an understanding of their population trends.

"The finding may indicate that individual populations of white sharks are more susceptible than previously thought to threats including fishing or changes in the local marine environment," Dr Jennifer Ovenden from DAFF says.

"The key will be to develop regional rather than national management strategies, and to ensure populations are monitored in both regions."


Story Source:

The above story is based on materials provided by ARC Centre of Excellence for Coral Reef Studies. Note: Materials may be edited for content and length.


Journal Reference:

  1. DC Blower, JM Pandolfi, BD Bruce, MdC Gomez-Cabrera, JR Ovenden. Population genetics of Australian white sharks reveals fine-scale spatial structure, transoceanic dispersal events and low effective population sizes. Marine Ecology Progress Series, 2012; 455: 229 DOI: 10.3354/meps09659

Cite This Page:

ARC Centre of Excellence for Coral Reef Studies. "Australia has two distinct white shark populations." ScienceDaily. ScienceDaily, 7 June 2012. <www.sciencedaily.com/releases/2012/06/120607185514.htm>.
ARC Centre of Excellence for Coral Reef Studies. (2012, June 7). Australia has two distinct white shark populations. ScienceDaily. Retrieved September 21, 2014 from www.sciencedaily.com/releases/2012/06/120607185514.htm
ARC Centre of Excellence for Coral Reef Studies. "Australia has two distinct white shark populations." ScienceDaily. www.sciencedaily.com/releases/2012/06/120607185514.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