Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Newly Discovered Juvenile Whale Shark Aggregation in Red Sea


Researchers Get Rare Glimpse into the Lives of Ocean's Gentle Giants

Whale sharks (Rhincodon typus)—which grow more than 30 feet long—are the largest fish in the world's ocean, but little is known about their movements on a daily basis or over years. A newly discovered juvenile whale shark aggregation off Saudi Arabia is giving researchers a rare glimpse into the lives of these gentle giants.

Whale sharks (Rhincodon typus), which grow more than 30 feet long, are the largest fish in the world's ocean. Little is known about their movements on a daily basis or over years. (Photo by Simon Thorrold, Woods Hole Oceanographic Institution)

Scientists from the Woods Hole Oceanographic Institution (WHOI) and colleagues from the King Abdullah University of Science and Technology (KAUST) and Massachusetts Division of Marine Fisheries report on the movements of whale sharks tagged at the site in a study published July 30, 2014, in the journal PLOS ONE.

During fieldwork in 2009, the research team found hundreds of juvenile whale sharks gathering on coral reefs near Al-Lith on the central coast of the Saudi Arabian Red Sea.

"The fact that there were so many whale sharks in such a small area gave us an opportunity to begin an unprecedented study to answer some of the basic questions," said Simon Thorrold, a biologist at WHOI and coauthor of the paper. "The discovery of the site provides a window into the movements and ecology of the species in a region that we were not necessarily expecting to see them in such high numbers."

The research team utilized three types of satellite transmitting tags to track the movements of 47 whale sharks from 2009 through 2011. The tags, which are placed just below the dorsal fins, measure temperature, depth, and light levels of the waters the fish swim in.  After several months, the tags pop off, float to the surface and beam data via the ARGO satellite system back to computers on shore.

Diving data from the tags revealed the sharks made frequent deep dives to at least 500 meters (1,640 feet).  Three of the tagged sharks made excursions below 1,000 meters (3,281 feet), with a maximum-recorded dive depth of 1,360 meters (4,462 feet).

Most of the sharks remained in the southern Red Sea throughout the time the tags were on. Some of the tagged individuals headed into the Indian Ocean, which may have been motivated by an abundant food supply related to seasonal upwelling. Whale shark diets vary both seasonally and geographically, but they are thought to feed mainly on zooplankton as well as algae, small fishes, fish eggs, and cephalopods.

"Interestingly, while some individuals that we tagged left the Red Sea and headed into the Indian Ocean, most remained relatively close to where they were tagged, suggesting that the area represents a critical juvenile habitat for this population," Thorrold added.

Adult whale sharks were not seen at the site, which may serve as a "staging ground" for juveniles before they move on to regional aggregations of larger sharks. To date, 12 whale shark aggregation sites have been identified globally.

"While all other juvenile whale shark aggregations are dominated by males, we found a sex ratio of 1:1 at the site in the Red Sea. The presence of so many female juvenile sharks may be of considerable significance to the global whale shark populations," Thorrold said.

Whale sharks were listed as “vulnerable” by the International Union for Conservation of Nature in 2000. Like other sharks and large rays, whale sharks likely have small litters of pups and are slow to reach sexual maturity.

The study highlights the need for more research on whale sharks as well as a multinational, cooperative effort to conserve populations in both the Red Sea and Indian Ocean.

"Our research on whale sharks in the Red Sea clearly shows that much remains to be learned about the species," said co-author Greg Skomal, a Massachusetts Division of Marine Fisheries biologist and WHOI adjunct scientist. "This newly discovered aggregation off Saudi Arabia likely plays an integral role in the natural history of this species in this region and, perhaps, well beyond."

"Eventually this work will tell us about where whales sharks are spending their time throughout their lives, where they're feeding, where they're breeding and where they're giving birth," added Thorrold. "Knowing where they go at different times of the year is critical to designing effective conservation strategies for the species."

Funding for this work was provided in part by KAUST baseline research funds and the U.S. National Science Foundation.

The Woods Hole Oceanographic Institution is a private, non-profit organization on Cape Cod, Mass., dedicated to marine research, engineering, and higher education. Established in 1930 on a recommendation from the National Academy of Sciences, its primary mission is to understand the ocean and its interaction with the Earth as a whole, and to communicate a basic understanding of the ocean's role in the changing global environment. For more information, please visit

WHOI Media Office | Eurek Alert!
Further information:

Further reports about: Aggregation Indian Ocean Oceanographic Shark WHOI Whale movements satellite sharks whale sharks

More articles from Ecology, The Environment and Conservation:

nachricht Don't forget plankton in climate change models, says study
27.11.2015 | University of Exeter

nachricht Using sphere packing models to explain the structure of forests
26.11.2015 | Helmholtz-Zentrum für Umweltforschung - UFZ

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Climate study finds evidence of global shift in the 1980s

Planet Earth experienced a global climate shift in the late 1980s on an unprecedented scale, fuelled by anthropogenic warming and a volcanic eruption, according to new research published this week.

Scientists say that a major step change, or ‘regime shift’, in the Earth’s biophysical systems, from the upper atmosphere to the depths of the ocean and from...

Im Focus: Innovative Photovoltaics – from the Lab to the Façade

Fraunhofer ISE Demonstrates New Cell and Module Technologies on its Outer Building Façade

The Fraunhofer Institute for Solar Energy Systems ISE has installed 70 photovoltaic modules on the outer façade of one of its lab buildings. The modules were...

Im Focus: Lactate for Brain Energy

Nerve cells cover their high energy demand with glucose and lactate. Scientists of the University of Zurich now provide new support for this. They show for the first time in the intact mouse brain evidence for an exchange of lactate between different brain cells. With this study they were able to confirm a 20-year old hypothesis.

In comparison to other organs, the human brain has the highest energy requirements. The supply of energy for nerve cells and the particular role of lactic acid...

Im Focus: Laser process simulation available as app for first time

In laser material processing, the simulation of processes has made great strides over the past few years. Today, the software can predict relatively well what will happen on the workpiece. Unfortunately, it is also highly complex and requires a lot of computing time. Thanks to clever simplification, experts from Fraunhofer ILT are now able to offer the first-ever simulation software that calculates processes in real time and also runs on tablet computers and smartphones. The fast software enables users to do without expensive experiments and to find optimum process parameters even more effectively.

Before now, the reliable simulation of laser processes was a job for experts. Armed with sophisticated software packages and after many hours on computer...

Im Focus: Quantum Simulation: A Better Understanding of Magnetism

Heidelberg physicists use ultracold atoms to imitate the behaviour of electrons in a solid

Researchers at Heidelberg University have devised a new way to study the phenomenon of magnetism. Using ultracold atoms at near absolute zero, they prepared a...

All Focus news of the innovation-report >>>



Event News

Fraunhofer’s Urban Futures Conference: 2 days in the city of the future

25.11.2015 | Event News

Gluten oder nicht Gluten? Überempfindlichkeit auf Weizen kann unterschiedliche Ursachen haben

17.11.2015 | Event News

Art Collection Deutsche Börse zeigt Ausstellung „Traces of Disorder“

21.10.2015 | Event News

Latest News

Siemens to supply 126 megawatts to onshore wind power plants in Scotland

27.11.2015 | Press release

Two decades of training students and experts in tracking infectious disease

27.11.2015 | Life Sciences

Coming to a monitor near you: A defect-free, molecule-thick film

27.11.2015 | Materials Sciences

More VideoLinks >>>