Valuation Report: South Africa White Sharks

White Sharks Alive: A value of $241.7 million

The lineage of the white shark traces back 14 million years, with a single divergent South African white shark being independent of the Mediterranean and Indo- Pacific Oceans (Australia and California) and the North West Atlantic (Florida) and Indian Ocean (South Africa) white shark gene pools. Very little is known about this divergent South African population. For example, how long they live for; where their nursery areas are; how large the population is; or how many are killed every year. What is known, though, is that over the past century, the population has fallen to critically low levels of genetic diversity. This means that it is unlikely that these white sharks will be able to recover to the point of being a healthy population.

According to a comment by Dr. Sara Andreotti in 2016, there remain only 333 of these white sharks capable of breeding. However, the minimum breeding population size to prevent inbreeding depression is 500 individuals. The loss of this iconic species has drastic trophic and economic implications which are already starting to be felt. The economic implications of losing the white shark are devastating. Already the white sharks have vanished from False Bay and the number of Gansbaai sightings is diminishing rapidly. This is a concern considering that white shark diving was one of South Africa’s fastest-growing tourism niches. It started in the 1990s and attracted a large number of shark-related tourists. Within the Western Cape, the number of shark-related tourists rose from c.a. 20,000 in 2000 to 100,000 in 2019.

While it’s known that the South African white sharks are disappearing, the exact cause is still under debate. There are sensationalized causes, but the more common consensus is that it is due to anthropogenic reasons:

Shark nets and bycatch are believed to be a main cause of the decline of the local population. Despite South Africa being the first country to grant white shark protection in 1991, they are still caught in high numbers as bycatch and in shark nets. For instance, from 1976 to 2008, 1,073 white sharks were reported as caught in the Kwazulu Natal Sharks Board shark nets.
Overfishing of key prey such as dusky, smoothhound, and soupfin sharks is another viable factor leading to the decline of the white shark population. From 2013 to 2017, dusky sharks were the main species caught in KwaZulu-Natal. According to the Department of Environment, Forestry & Fisheries (DEFF), it was estimated that from 1991 to 2016, the populations of the smoothhound and the soupfin sharks declined by 42.3% and 50.9% respectively.
Since 2017, the carcasses of nine white sharks that fell prey to orcas have been found in False Bay and Gansbaai. These sharks are believed to have been targeted by orcas, which led to the misconception that orcas are to blame for the collapse of the white shark population. However, Fisher (2021) suggests that there had been a significant drop in the number of pelagic sharks, an essential prey of the orcas, due to overfishing. This resulted in the orcas hunting white sharks. While the orcas may have contributed to some white shark deaths and the relocation in particular of the False Bay sharks, there remains a debate as to whether they are the main cause for the disappearance of white sharks. This is due to the fact that white shark sightings began declining in 2013 alongside the decline in the number of smaller sharks.

One complexity when it comes to the valuation of the sharks, in general, is the limited availability of survey data. In order to overcome this challenge, the shark population trends are inferred using the local relative abundance trend data from Hammerschlag et al. (2019), combined with the midpoint of the 2014 range estimate published by Andreotti et al. (2016). The ability to model the target species’ population is vital as it is one of the fundamental processes for valuing biodiversity. This requires an understanding of the local and generic population dynamics. The analysis uses the average 2014 population size of 438 individuals. While we use this as the source of reference, it is acknowledged that the population may be smaller, as general Western Cape white shark sightings have declined since the 2014 survey.

There is a deep-rooted debate in terms of this particular white shark population. One side of the debate is that there has been a significant loss of the white sharks and the rate at which they are declining may lead to their ultimate local extinction. The other side of the debate is that the rate of loss is not as severe and that the sharks have merely migrated from their known locations. In order to uphold a neutral position, this report analyses both a pessimistic and a conservative scenario to establish the outlook for the population. However, for the valuation, the conservative scenario outcomes are applied.

The baseline value of the white shark population in South African waters is $241.7 million. This value is comprised of the following:

+ Aesthetic Value: $104.9 million

+ Economic Value: $107.6 million

+ Hedge Value: $2.6 million

= Species Existence value: 215.2 million

+ Impact Value: $26.5 million

= Total Conservation Value: $341.7 million

Based on the 438 midpoint estimated number of sharks in the region, the implied average value per individual over 30 years of $551,751.

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. Sara Andreotti, Dr. Enrico Gennari, Dr. Alison Kock and Chris Fallows for their expert advice in preparing this report and Nicholas Kalikow for his financial support.

Stefanie BrendlSeptember 27, 2022