Marine scientists are sounding the alarm as white shark sightings off the Western Cape coast have plummeted to alarming lows, prompting urgent calls for enhanced protective measures to safeguard the iconic species.
According to a recent research paper published on ScienceDirect, co-authored by marine biologist Dr Enrico Gennari and international conservationists, white shark sightings in traditional areas have dwindled to fewer than 10 per year, marking a stark decline from previous levels.
Dr Gennari estimates that South Africa may be losing between 60 to 80 white sharks annually, underscoring the pressing need for updated and modernised protective measures.
While South Africa pioneered a precautionary approach to white shark conservation in 1991, recent declines in sightings suggest that existing strategies may not be sufficient to safeguard the species.
The 1991 programme called the "White Shark Research Project," was significant for white shark conservation efforts. Led by marine biologist Chris Fallows and filmmaker Jeffery K. Kerr, the project aimed to study the behaviour and ecology of great white sharks around Seal Island in False Bay.
The research conducted through this programme helped in understanding the habitat requirements, feeding patterns, and migratory behaviours of great white sharks, which contributed to the development of conservation strategies for this iconic apex predator.
In the 2024 study, researchers argue for the continuation of a precautionary stance, emphasising the importance of prioritising conservation efforts amid declining populations.
"We suggest a precautionary approach to be taken in light of concurrent local declines documented at historical aggregation sites, as well as the reduction in sightings of large mature individuals currently being observed," the research paper states.
The urgency for enhanced protection measures stems from recent findings challenging previous studies suggesting population stability.
A research paper published in October 2023 indicated stable population numbers since 1991, but subsequent analysis by Dr Gennari and his team revealed glaring gaps in the data, casting doubt on the conclusions drawn.
Addressing concerns raised by the 2023 study, Dr Gennari highlighted discrepancies in the interpretation of percentage figures, noting that an 80% decrease in one area does not equate to an 80% increase elsewhere.
The need for updated methodologies and comprehensive data analysis is paramount in accurately assessing the status of white shark populations.
While the 2023 study suggested an eastward movement of white sharks, recent research challenges this assertion, citing factors such as increased drone surveillance and habitat expansion due to marine protected areas and new ports as potential contributors to heightened sightings on the east coast.
The presence of orcas, known predators of white sharks, may also influence sightings, with their increased presence in certain areas possibly driving white sharks away.
As concerns mount over declining populations and shifting dynamics, marine scientists stress the critical need for immediate action to protect white sharks and preserve marine biodiversity.
IOL Environment