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:3/31/2016)... 2016   LegacyXChange, ... "Company") LegacyXChange is excited to release its ... to be launched online site for trading 100% guaranteed ... will also provide potential shareholders a sense of the ... an industry that is notorious for fraud. The video ...
(Date:3/22/2016)... PROVO and SANDY, ... Screening Ontario (NSO), which operates the highest sample volume ... testing, and Tute Genomics and UNIConnect, leaders in clinical ... today announced the launch of a project to establish ... testing panel. NSO has been contracted ...
(Date:3/15/2016)... , March 15, 2016 Yissum Research ... the technology-transfer company of the Hebrew University, announced today ... remote sensing technology of various human biological indicators. Neteera ... $2.0 million from private investors. ... on the detection of electromagnetic emissions from sweat ducts, ...
Breaking Biology News(10 mins):
(Date:5/4/2016)... ... 04, 2016 , ... PBI-Gordon Corporation is pleased to announce Doug Obermann has ... his career at PBI-Gordon in February 1988, after finishing his masters in agronomy from ... from customer service to national product manager, to helping develop, name and launch many ...
(Date:5/3/2016)... , ... May 03, 2016 , ... ... enterprise talent development, skill-building and compliance training platform on mobile devices, today released ... Overview of Regulatory Requirements for Medical Devices. The course is essential for owners ...
(Date:5/3/2016)... ... May 03, 2016 , ... ... of Dr. Nancy Gillett to its Board of Directors. Dr. Gillett recently retired ... Corporate Executive Vice President and Chief Scientific Officer. A board-certified veterinary pathologist, Dr. ...
(Date:5/3/2016)... - And Other Rising Companies - a ... Biologics  - Biosimilar Drug Producers - Your ... Who are the most important and promising ... potentials? Discover, in our updated survey, organisations, outlooks from ... forecasting. Visiongain,s new study analyses ...
Breaking Biology Technology: