Valuation Report: Bahamas Great Hammerhead Sharks

 

photo by Jim Abernethy

 

Great Hammerhead sharks Alive: A value of US$29.4 million

The great hammerhead shark (Sphyrna mokarran) is the largest of the Sphyrnidae family. They are both coastal pelagic and semi-oceanic sharks that have been found worldwide inhabiting tropical seas. Unfortunately, the population size of these unique sharks has declined significantly. According to the Mokarran Protection Society, the population has collapsed by more than 80% in 70 years, resulting in the IUCN in 2019 declaring the species as Critically Endangered. According to the IUCN, the main reason for the global population decline is that the great hammerhead shark is caught both as a target and as bycatch in commercial and small-scale pelagic longline, purse seine, and gillnet fisheries. It is also often caught in coastal longlines, gillnets, trammel nets, and sometimes trawls. Those that are caught are often kept for their fins. Fins from hammerhead species are one of the main fins sold in the fin trade. The three hammerhead species represented 4% of Hong Kong shark fin imports in 2014.

One of the best locations to dive with Great Hammerhead sharks is in the Bahamas. Due to its proximity to the Gulf Stream the region provides warm, nutrient-rich waters that support marine life and mangrove nurseries. Sharks are deemed protected in the Bahamas and play a vital role in supporting the local economy and, as an apex predators, maintaining a healthy local ecosystem. In 2011, the Bahamas declared 200 nautical miles from the Bahamian shoreline a shark sanctuary. The shark diving industry has flourished and shark tourism, according to Haas et al. (2017), 43% of divers who visited the Bahamas wanted to dive with sharks.

 
 

The greatest economic value that is generated by the great hammerhead shark population is currently the cumulative shark dive tourism-related value. In total, $8.8 million. This includes:

  • Tourism employment: $4.6 million

  • Recreation income: $2.3 million

  • Hotel income: $0.5 million

  • Restaurant income: $0.4 million

  • Other income (games, souvenirs, other services): $1.0 million

The sharks also, directly and indirectly, create value for the entertainment industry, specifically relating to the growing interest in the great hammerhead shark in events such as Shark Week. Over the last decade, there have been more episodes starring the great hammerhead shark in the Bahamas, with 10 airing from 2017-2022. This was calculated to a total value of $11.0 million. Added up the total economic value is $19.8 million.

Ecosystem Services

One of the important elements in valuing the ecosystem services sharks provide is to look at the key local food web interactions for the great hammerhead shark in the waters around the Bahamas and other species that cohabit with the great hammerhead sharks. It includes predators and prey. The relationship matrix is vital in understanding the importance of the great hammerhead shark relative to the other species.

 

graphic by Endangered Wildlife OÜ

 

The biggest data gap we struggled with is the Carbon value that one should attribute to sharks. While it is understood that sharks contribute to solving the planet’s carbon threat, there is a lack of scientific evidence that can justify their actual impact in terms of carbon value. Future studies and reports will close this gap, at which time the value of sharks will increase greatly. We will update these reports as new data becomes available.

The baseline value of the great hammerhead shark population in the Bahamas waters is $29.4million over a 30-year period. This value is comprised of the following:

+ Aesthetic Value: $0.5 million

+ Economic Value: $19.8 million

+ Hedge Value: $3.7 million

= Species Existence value: $24.0 million

+ Impact Value: $5.4 million

= Total Conservation Value: $29.4 million

Averaging the total value over the estimated population size of 100 individuals, the value per individual is $294,000.

While all of the numbers above are great arguments why we should protect our sharks as an investment, ultimately, the most important reason why sharks matter is the important role they play in keeping our ocean healthy. And that should be the overriding reason why we respect and protect sharks.

A quick overview of the components of the report:

To request the full report, please contact us via email.

 
 

SPECIAL THANKS

Endangered Wildlife OÜ and Shark Allies would like to thank Dr. Tristan Guttridge for his expert advice in preparing this report and ElasmOcean e.V. for their financial support.

Stefanie Brendl