Although the exact numbers are debated, the UN acknowledges that the global catch of sharks has increased four-fold over the last 50 years and currently represents many tens of millions of sharks killed every year. Since sharks grow slowly, breed late in life and produce only a few pups at each attempt, their populations are very vulnerable to overfishing and shark numbers almost everywhere are in decline as a result of unsustainable harvesting.
Arguments that sharks should be preserved because they are necessary for the health and performance of marine ecosystems have failed to stop their global demise because of the perceived high value by weight placed on shark fins.
In 2010, the international Pew Charitable Trust commissioned a report from AIMS and the University of Western Australia (providing expertise in natural resource economics) to establish the value of shark tourism to the economy of the Pacific Island nation of Palau, which declared the world's first shark sanctuary in 2009.
The analysis quantified the economic benefits of Palau's shark-diving industry and found that it far exceeds the potential return from shark fishing. The average value of a dead shark was estimated as a one-off return of just US$108. In contrast, the annual value to the tourism industry of the same shark on a tourism dive site was estimated to be US$179,000 or US$1.9 million over its life. The difference is a staggering 17,000 multiple of value in favour of conservation.