23 September 2020.

Introduction:

According to the wildlife department,330  elephants died in Botswana’s famed Okavango Delta .The first mass death occurred in May 2020 when 169 elephants were found dead.Later in July 281 were found dead. The cause of death is the water poisoned by cyanobacteria.

About Cyanobacteria:

• Cyanobacteria are microscopic organisms common in water and sometimes found in soil.
• They are microscopic organisms that hold blue pigment called  phycocyanin.
• These bacteria capture bright light through this pigment to prepare food.
• Not all produce toxins but scientists say toxic ones are occurring more frequently as climate change drives up global temperatures.
• In Botswana the climate change has triggered the bacteria to produce more toxins as the water temperature increased making the conditions more favourable for bacteria to grow.
• This increased number of bacteria caused toxic blooms.

     Controversies:

• Why only elephants died?
• A cyan bacterium grows on the edges of the water bodies while elephants drink water from the middle of the water body.

     IUCN Status:Listed as vulnerable under the  IUCN Red List of Threatened Species.IUCNH launches “Green Nudges” programme