Navigation Links
UIC biologists use DNA to study migration of threatened whale sharks
Date:4/7/2009

Whale sharks -- giants of the fish world that strike terror only among tiny creatures like the plankton and krill they eat -- are imperiled by over-fishing of the species in parts of its ocean range.

That threat is underscored in a new study from geneticists led by Jennifer Schmidt, University of Illinois at Chicago associate professor of biological sciences, reported online April 7 in the journal PLoS One.

Schmidt and her colleagues studied the DNA of 68 whale sharks from 11 locations across the Indian and Pacific Oceans and the Caribbean Sea -- an area that covers most of the shark's known range. Results showed little genetic variation between the populations, which indicates migration and interbreeding among far-flung populations of the big fish.

"Our data show that whale sharks found in different oceans are genetically quite similar, which means that animals move and interbreed between populations," said Schmidt. "From a conservation standpoint, it means that whale sharks in protected waters cannot be assumed to stay in those waters, but may move into areas where they may be in danger."

A tropical fish that can grow 50 feet or longer and weigh over 20 tons, a whale shark's range can span oceans. They do not breed until they are about 25 to 30 years old, so it will take a long time for the species to recover from recent population declines.

Whale sharks are listed as threatened, but not every country protects them. The large animals are especially prized by fishermen for meat and fins used in soup.

Little is known about the shark's biology, perhaps because they have been studied primarily near shore, while mature animals may breed and give birth out in the open ocean. Nor is much known about neonatal or juvenile sharks, including where they grow to maturity, or how and when they move between regions. That has made devising effective conservation efforts a problem.

"The only real threat to whale sharks is us," said Schmidt. "To design proper conservation plans, we need to understand the sharks' lifestyle. We can only protect their habitat if we know what habitat they use."

Schmidt credits some countries for closing whale shark fisheries and hopes that efforts such as ecotourism programs, which sometimes include swims with the gentle giants, may prove an attractive economic alternative to fishing.

With the money brought in by well-managed ecotourism programs, Schmidt said, "people in many countries have come to realize that whale sharks are more valuable alive than dead."


'/>"/>

Contact: Paul Francuch
francuch@uic.edu
312-996-3457
University of Illinois at Chicago
Source:Eurekalert

Related biology news :

1. Penn biologists demonstrate that size matters... in snail shells
2. Two innovative University of Texas at Austin biologists become HHMI Early Career Scientists
3. Plant biologists discover gene that switches on essence of male
4. Cleaning up oil spills can kill more fish than spills themselves, say Queens biologists
5. Biologists solve mystery of black wolves
6. Biologists discover link between CGG repeats in DNA and neurological disorders
7. Biologists learn structure, mechanism of powerful molecular motor in virus
8. Queens University biologists find new environmental threat in North American lakes
9. Biologists discover gene behind plant sex mystery
10. Caltech geobiologists discover unique magnetic death star fossil
11. Biologists, educators recognize excellence in evolution education
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/14/2016)... 2016 http://www.apimages.com ) - ... - Renvoi : image disponible via AP Images ... --> DERMALOG, le leader de ... lecteurs d,empreintes digitales pour l,enregistrement des réfugiés en ... pour produire des cartes d,identité aux réfugiés. DERMALOG ...
(Date:3/11/2016)... -- --> --> ... Market by Technology (Pattern Recognition), by Component (Hardware, Software, ... (On-Premises and Cloud), by Industry Vertical and by Region ... global market is expected to grow from USD 12.49 ... at a CAGR of 19.1%. , ...
(Date:3/10/2016)... Pa. , March 10, 2016   Unisys Corporation ... Customs and Border Protection (CBP) is testing its biometric ... San Diego to help identify certain non-U.S. ... . The test, designed to help determine the efficiency ... environment, began in February and will run until May 2016. ...
Breaking Biology News(10 mins):
(Date:5/24/2016)... ... May 24, 2016 , ... Cell ... injuries, will be accelerated by research at Worcester Polytechnic Institute (WPI) that yielded ... healing and tissue regeneration. , The novel method, developed by WPI faculty members ...
(Date:5/23/2016)... ... , ... The need for blood donations in South Texas and across the nation is growing. ... Tissue Center, blood donations are on the decline. In fact, donations across the country are ... in South Texas in the last four years alone. , There is no substitute for ...
(Date:5/23/2016)... and LONDON , May 23, 2016 ... Could See Frontage Boost Efficiency by 40% - Frontage ... - Frontage Enforce Quality, Compliance and Traceability Within the Bioanalytical ... with labs in the United States and ... to be deployed across its laboratory facilities. In addition to ...
(Date:5/20/2016)... ... , ... The leading Regenerative Veterinary Medicine Company, VetStem Biopharma ., is ... 100 of their own patients with the VetStem Cell Therapy. Each of these veterinarians ... their patients. , The veterinarians are Dr Ross Rich former owner of Cave ...
Breaking Biology Technology: