dreamyfreckless
About five species of freshwater dolphins are known, of which one has already gone extinct (the Baiji or Chinese River dolphin). The remaining four are classified as (critically) endangered. To raise awareness for these dolphins, the International Freshwater Dolphin Day takes place on October 24 each year in different countries in Southeast Asia.
Disclaimer: I am not from Asia, I merely think river dolphins deserve more love and recognition.
The Irrawaddy Dolphin, which is celebrated as a unique part of Cambodian heritage on October 24. Picture via http://www.xinhuanet.com/english/2020-10/24/c_139463734.htm
The Ganges River Dolphin, common in Bangladesh, India and Nepal. Picture via https://indusscrolls.com/nature-revives-ganges-river-dolphin-appears-again-in-meerut-video
Some useful links:
https://www.tbsnews.net/bangladesh/environment/international-freshwater-dolphin-day-day-celebrate-enigmatic-aquatic-mammals
https://wwf.panda.org/wwf_news/?202087/Freshwater-dolphin-day
https://www.wwf.org.kh/projects_and_reports2/mekong_dolphins/
https://iucn-csg.org/24th-october-is-freshwater-dolphin-day-2/
(inspired by yashika22's Ganges River Dolphin stamp request)