Credit: @chrisfallowsphotographyRecent study questions the idea of a steady motion of white shark populations toward the east along South Africas shores.A team of marine biologists, specialists in shark ecology, genetics, and fisheries, has challenged the findings of a recent research study which claimed that the population of white sharks in South Africa has not decreased, however simply redistributed eastwards to get away predation from orcas.In September 2023 the post titled “Decline or moving distribution?” Critique of the Original Studys ConclusionsIn a rebuttal post published in the exact same journal recently, titled “Uncertainty remains for white sharks in South Africa, as population stability and redistribution can not be concluded by Bowlby et al (2023 )”, the group of worried marine biologists highlight several problems with the inferences and methods made in the study mentioned above, and argue that the information, as presently evaluated and interpreted, can not support the claims made about population stability, nor redistribution, of South Africas white sharks.Dr Enrico Gennari, director of the Oceans Research Institute and lead author, says they felt obliged to raise these issues provided what it suggests for management: “If the white shark population is steady, there is no requirement for concern.” If the entire population was certainly regionally steady and those observed simply moved from East to West, one would have expected the number of white sharks in Algoa Bay to be significantly greater,” they write.Secondly, with regard to the claim that the expected white shark redistribution eastward was driven by shark-eating whales, they point out that the start of white shark decreases in False Bay (2012/13), Gansbaai (2013/14) and Mossel Bay (2015) predates the very first appearance of those orcas in False Bay and in Gansbaai in 2015, and in Mossel Bay just in 2017. Our issue is that unsupported claims of population stability could endanger conservation actions urgently required for white sharks,” she warns.The group of concerned marine biologists advises authorities such as the Department of Forestry, Fisheries and Environment to take a preventive method in light of the decreases in white shark sightings from their historic hotspots, the ensuing negative effect on South Africas ecotourism economy, the reduction in sightings of large mature white sharks, both in the Western and Eastern Cape, the very low genetic diversity of this population, the historical and present unsustainable levels of white shark deaths from the deadly shark control program of the KwaZulu-Natal Sharks Board, and the newly exposed white shark deaths by a coastal shark longline fishery in South Africa.
Credit: @chrisfallowsphotographyRecent research study questions the idea of a steady motion of white shark populations toward the east along South Africas shores.A team of marine biologists, professionals in shark ecology, genes, and fisheries, has challenged the findings of a current study which claimed that the population of white sharks in South Africa has not decreased, however simply redistributed eastwards to run away predation from orcas.In September 2023 the article titled “Decline or shifting distribution?” If the whole population was certainly regionally steady and those observed just moved from East to West, one would have anticipated the number of white sharks in Algoa Bay to be significantly greater,” they write.Secondly, with regard to the claim that the expected white shark redistribution eastward was driven by shark-eating orcas, they point out that the onset of white shark decreases in False Bay (2012/13), Gansbaai (2013/14) and Mossel Bay (2015) precedes the first appearance of those orcas in False Bay and in Gansbaai in 2015, and in Mossel Bay only in 2017. Our concern is that unsupported claims of population stability might jeopardize conservation actions urgently required for white sharks,” she warns.The group of worried marine biologists advises authorities such as the Department of Forestry, Fisheries and Environment to take a precautionary technique in light of the declines in white shark sightings from their historic hotspots, the consequent unfavorable impact on South Africas ecotourism economy, the decrease in sightings of large fully grown white sharks, both in the Eastern and western Cape, the very low hereditary diversity of this population, the historic and existing unsustainable levels of white shark deaths from the lethal shark control program of the KwaZulu-Natal Sharks Board, and the recently exposed white shark deaths by a coastal shark longline fishery in South Africa.
