[ASC-media] Media release: more whale sharks return

JCA Media jca.media at starclass.com.au
Thu Dec 20 03:39:34 CET 2007


Embargoed for release until 26 December 2007


MORE WHALE SHARKS RETURN TO NINGALOO

The population of whale sharks visiting Ningaloo, Western Australia, appears to be healthy according to the results of a new, twelve-year study in the upcoming issue of the international journal Ecological Applications*.  The study contradicts previous findings of declines in the Ningaloo population and presents a new approach to analyzing the species. With many global reports finding shark populations in decline, these results provide a glimpse of hope.

"The study suggests that the management practices at Ningaloo are working for the whale shark", said Rolex Awards for Enterprise Laureate and marine biologist Brad Norman. "It is vital that this knowledge be made available to other parts of the world already undertaking or embarking upon whale shark conservation and eco-tourism projects." 

Mr. Norman says global concern over the whale shark's future remains justified because of apparent declines in places where whale sharks are still hunted for their fins and meat and in view of sharks' slow population recovery rates.

Cutting-edge software was used to collect data for long-term monitoring, analysis, and management of this local aggregation of one of the world's rarest creatures. The study incorporated 5100 underwater images contributed by hundreds of researchers, divers and ecotourists. The Ningaloo study forms part of a broader, global project analyzing the vulnerability of the deep sea giant to extinction. Population models based on the photographs, which represent almost ten times more data collected than any previous study, indicated a modest increase in the number of whale sharks returning annually to the northern area of Ningaloo Reef from 1995-2006. 

The study also demonstrated the robustness and reliability of computer-assisted photo-identification in combination with ecotourism as a new way of studying populations of rare and endangered animals at a relatively low cost. The marine environment is expensive to research, and this type of collaborative 'citizen science' is a cost-effective, achievable way of better understanding the seas. 

"To study whale sharks in a meaningful way, we really had to rethink how we collect data and how we analyze it. We began our work from the ground up, building our own tools on a tight budget and designing our study to be collaborative from the start." said Jason Holmberg, a programmer and author on the study. "The results surpassed our expectations, allowing hundreds of individuals to contribute and providing the necessary data to obtain a closer look at the population's health. This model can be cross-applied to a lot of other research areas."

The study was started in 1995 by West Australian marine scientist Brad Norman. His US colleagues Jason Holmberg and Dr Zaven Arzoumanian adapted astronomical software (originally developed for use with the Hubble space telescope) to recognize the unique pattern of spots on the skins of individual whale sharks. This technology was used recently to identify the 1000th whale shark from over 12,000 photos collected by a global research network, a remarkable feat for so rare an animal. 

The project received international recognition with a Rolex Award for Enterprise in 2006.

The authors of the study also discovered that approximately two-thirds of the sharks visiting the reef every year are returning after previous visits. However, the remainder passed through the study area without further resighting, suggesting that some sharks swimming the reef may only be short-term visitors. 

Despite the encouraging news from Ningaloo, the authors of the study caution that little is still known about the habits of the giant fish, especially when it is in open ocean or down deep. Their ongoing work may hold a few more surprises. "This study is the tip of the iceberg for whale sharks. Every time we look at the data, we ask more questions. That's the real joy of exploration." says Dr. Arzoumanian. 

For more information about the study:
http://www.whaleshark.org/paperfacts.pdf

For more information about whale sharks:
http://www.whaleshark.org/whaleshark.pdf

For more information about ECOCEAN:
http://www.whaleshark.org/ECOCEAN.pdf

Additional information about whale shark research can be found at:
http://www.whaleshark.org

For further information, please contact:
Jason Holmberg (USA) 
231 798 3768
jason at whaleshark.org

Brad Norman (Australia) 
0414 953 627
brad at whaleshark.org

* published by the Ecological Society of America





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