Incident Overview:
- Event: Over 350 elephant deaths occurred in northern Botswana during May-June 2020.
- Suspected Cause: Initially attributed to algal toxins, though evidence was inconclusive at the time due to restricted movements during COVID-19.
Key Findings from Study:
- New Evidence:
- Study published in Science of The Total Environment links toxic algal blooms in waterholes to the mass deaths.
- Satellite data analyzed 3,000 waterholes near elephant remains, revealing increased algal activity in 2020 compared to previous years.
- Algal Bloom Characteristics:
- Higher levels of blue-green algae (cyanobacteria) detected near waterholes.
- Likely caused by a wet year preceding a very dry one, creating favorable conditions for toxic algal blooms.
- Comparison with Past Patterns:
- 2020 carcasses were more dispersed compared to typical death patterns.
- 20 waterholes showed significant algal blooms during the die-off period, with the highest algal biomass recorded from 2015–2023.
Lead author Davide Lomeo, a PhD student in the Department of Geography at King’s College London, noted, “Our analysis shows animals were very likely poisoned by watering holes where toxic blooms of blue-green algae had developed.”
Broader Implications:
- Climate Change Impact:
- Escalating concerns over drought and climate change effects on the Okavango Delta.
- Projections for southern Africa indicate drier and hotter conditions, potentially worsening water quality and availability.
- Ecological Significance:
- Botswana hosts a third of Africa’s elephant population, making the event a severe ecological concern.
This tragedy illustrates how climate change can indirectly trigger ecological disasters. As the effects of global warming intensify, the conservation of vital ecosystems like the Okavango Delta becomes ever more critical—not just for elephants but for the broader biodiversity and communities that depend on them.
Source: PTI