Tracking the deep sea paths of tiger sharks

January 8, 2014
This shows the underwater release of one of the tiger sharks with two of the authors. Credit: Thomas Vignaud

Shark research scientist, Dr Jonathan Werry, has undertaken a four year study tracking the migratory patterns of tiger sharks (Galeocerdo cuvier) across the Southwest Pacific.

The research, in collaboration with the French government, followed the movement of 33 tiger sharks (1.54 to 3.9 m total length) across the Coral Sea between New Caledonia and the Great Barrier Reef.

The animals were tagged with satellite and acoustic transmitters and their localised movements monitored by receivers in New Caledonia, the Chesterfield and Lord Howe Islands in the Coral Sea and the east coast of Queensland, Australia.

Dr Werry said the findings, to be published in the open access journal PLOS ONE, reveal that coastal marine parks provide only brief protection for these important marine predators while oceanic reefs, vital to their ecology, are overlooked.

"In this study we looked at migratory movements and fidelity to specific reefs for tiger sharks tagged in New Caledonia, the east coast of Australia (the Great Barrier Reef) and oceanic reefs in the centre of the Coral Sea," Dr Werry said.

"We found the monitored sharks utilised three dimensional activity spaces of between 503 and 2360 kmᶟ but the range of movement varied consistently with the age and sex of the animal," he said.

One 3.7 m female tiger shark was recorded to a previously unknown depth of 1136m.

"When it comes to traveling long distances adult females are the primary custodians for the 'across Coral Sea' migrations, and this is probably driven by triennial reproductive cycles," Dr Werry said.

"Pre-reproductive females and mature male tiger sharks on the other hand, were observed to demonstrate extraordinary year round residency in the oceanic Chesterfields reef, so this area appears to be a very important habitat for them."

On coastal reefs, all of the monitored tiger sharks were found to be transient.

Dr Werry said understanding the habitat-use and migration patterns of large sharks is extremely important for assessing the effectiveness of Marine Protected Areas, as well as the vulnerability of these predators to fisheries and environmental influences and management of shark-human interactions.

"Management strategies need to consider the wide-ranging movements of large (sub-adult and adult) male and female at the individual level, in particular when fidelity to specific coastal reefs may be consistent across groups of individuals," he said.

The importance of oceanic Coral Sea reefs should be a priority for future research."

Explore further: Australia's Coral Sea is 'biodiversity hotspot'

More information: DOI: 10.1371/journal.pone.0083249

Related Stories

Australia's Coral Sea is 'biodiversity hotspot'

August 20, 2011

The Coral Sea off Australia's northeast coast is one of the last remaining places brimming with large predatory fish such as sharks and tuna, a study released Saturday found.

Sharks dive deep on moonlit nights

April 15, 2013

(Phys.org) —The Moon, water temperature and even time of day affect the diving behaviour of sharks, according to new research at The University of Western Australia.

Recommended for you

Secrets of a heat-loving microbe unlocked

September 4, 2015

Scientists studying how a heat-loving microbe transfers its DNA from one generation to the next say it could further our understanding of an extraordinary superbug.

Plants also suffer from stress

September 4, 2015

High salt in soil dramatically stresses plant biology and reduces the growth and yield of crops. Now researchers have found specific proteins that allow plants to grow better under salt stress, and may help breed future generations ...

Ancient walnut forests linked to languages, trade routes

September 4, 2015

If Persian walnut trees could talk, they might tell of the numerous traders who moved along the Silk Roads' thousands of miles over thousands of years, carrying among their valuable merchandise the seeds that would turn into ...

Huddling rats behave as a 'super-organism'

September 3, 2015

Rodents huddle together when it is cold, they separate when it is warm, and at moderate temperatures they cycle between the warm center and the cold edges of the group. In a new study published in PLOS Computational Biology, ...

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.