Navigation Links
Disappearing act of world's second largest fish explained
Date:5/10/2009

Researchers have discovered where basking sharks the world's second largest fish hide out for half of every year, according to a report published online on May 7th in Current Biology, a Cell Press publication. The discovery revises scientists' understanding of the iconic species and highlights just how little we still know about even the largest of marine animals, the researchers said.

"While commonly sighted in surface waters during summer and autumn months, the disappearance of basking sharks during winter has been a great source of debate ever since an article in 1954 suggested that they hibernate on the ocean floor during this time," said Gregory Skomal of Massachusetts Marine Fisheries. "Some 50 years later, we have helped to solve the mystery while completely re-defining the known distribution of this species."

Using new satellite-based tagging technology and a novel geolocation technique, the researchers found that basking sharks make ocean-scale migrations through tropical waters of the Atlantic Ocean during the winter, traveling at depths of 200 to 1,000 meters. Their data show that the sharks sometimes stay at those depths for weeks or even months at a time. "In doing so, they have completely avoided detection by humans for millennia," Skomal said, emphasizing that as one of the very largest of marine animals, the sharks grow to over 10 meters and weigh as much as seven metric tons.

Skomal said they were "absolutely surprised" when they first received a signal from the tagged sharks coming from the tropical waters of the western Atlantic, in the vicinity of the Caribbean and Bahamas. After all, basking sharks were always believed to be cool-water sharks, restricted to temperate regions.

Several factors had made basking sharks a challenge to study. On top of the fact that they disappear for long periods of time, they also feed exclusively on plankton. That means they can't readily be captured with traditional rod-and-reel methods. And even when the sharks are found closer to the ocean surface, they spend their time in the cool-temperature, plankton-rich waters that limit underwater visibility and make diving difficult.

The findings could have important implications for the conservation of basking sharks, which have shown some signs of dramatic decline in the last half century and are listed as threatened by the International Union for Conservation of Nature.

"Coupled with recent genetic data, our finding indicates that the Atlantic population and perhaps the world population are connected and may constitute a single population," Skomal said. "Hence, the global population of basking sharks may be even smaller than previously thought." Efforts to boost basking sharks' numbers will therefore need to be coordinated at a global scale.


'/>"/>

Contact: Cathleen Genova
cgenova@cell.com
617-397-2802
Cell Press
Source:Eurekalert

Related biology news :

1. A Great Lakes mystery: The case of the disappearing species
2. Californias wildflowers are disappearing, new book by UCR ecologist cautions
3. The best both of worlds -- how to have sex and survive
4. Quantum weirdness, parallel worlds, dinosaur poop, and the ultimate fate of the universe...
5. 60 second test could help early diagnosis of common brain diseases
6. BIO-key Reports Second Quarter 2007 Results
7. Communication Intelligence Corporation Reports Second Quarter 2007 Financial Results
8. Weight gain between first and second pregnancies associated with increased odds of male second child
9. Decisions on the second round of the Excellence Initiative announced
10. Second genetic link to weight and obesity
11. A new analysis method allows to find out the sex of the baby from the second month of pregnancy
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:1/15/2016)... Puerto Rico , Jan. 15, 2016 ... big and small to find new ways to ensure ... culture. iOS and Android ... based on biometrics, transforming it into a hardware authorization ... that users swipe their fingerprint on their KodeKey enabled ...
(Date:1/11/2016)... , Jan. 11, 2016  higi, the leading ... 10,000 retail locations, web and mobile, today announced ... million from existing investors. --> ... devoted to further innovate higi,s health platform – ... web portal – including expanding services and programs ...
(Date:1/7/2016)... , Jan. 7, 2016 Various ... for biopharmaceutical products such as biologics and biosimilars. ... to reduce healthcare expenditure, growing demand for cost-effective ... aging population. Biosimilars are similar versions of their ... regards to their quality, safety, and efficacy. The ...
Breaking Biology News(10 mins):
(Date:2/8/2016)... Maryland (PRWEB) , ... February 08, 2016 , ... Information ... BSI Web product. The upgrade represents a completely new technical foundation and is ... will offer a responsive design interface, significantly increased speed for search results, a streamlined ...
(Date:2/8/2016)... active R&D program for the development of future natural products ... unique research and development center in Israel ... Stockton has a variety of products ... is active in more than 35 counties worldwide. ... flagship product Timorex Gold ® is used to ...
(Date:2/6/2016)... ... 06, 2016 , ... Contact:, Abby Mitchell, Communications Manager, Phone: ... Sponsors Teacher Training Program , Bite of Science Dinner Event to Strengthen Science ... in Education (CEE) will sponsor a Bite of Science professional enrichment session, cost-free, ...
(Date:2/5/2016)... SAN FRANCISCO , February 5, 2016 ... AMBS), a biotechnology company focused on developing products ... it has requested Rare Pediatric Disease Designation (RPDD) from ... retinitis pigmentosa (RP) with MANF. MANF was previously granted ... December 2014. --> Amarantus BioScience Holdings, Inc. ...
Breaking Biology Technology: