Ocean acidification is from human-driven increased levels of CO₂ in the atmosphere, which is dissolving into the ocean.

The ocean’s average pH is now around 8.1, which is alkaline, but as the ocean continues to absorb more CO₂, the pH decreases and the ocean becomes more acidic which prevents marine life from thriving.

pathways:

11.08.2022 / PewTrust.org /  8 Facts About Antarctic Krill Show Why They Need Greater Protection

21.07.2022 / Earth.org / The ‘Evil Twin’ of Global Warming: What is Ocean Acidification?