Thank you for your succinctly scarifying editorial on anthropogenic threats to marine wellbeing (We should care more and invest more, 14 August). One of the issues raised, ocean acidification driven by rising levels of atmospheric carbon, threatens not just visible species like shellfish and coral, but microscopic phytoplankton or diatoms, single-celled algae so small a million dwell in a litre of seawater.
There are more than 10,000 species of diatom, each as exquisitely and diversely patterned as snowflakes. They generate half Earth’s oxygen – every second breath we draw is their gift – catalyse cloud formation hence weather, are a major carbon sink, and the lynchpin of the marine foodchain. Phytoplankton cannot form skeletons in acidifying oceans; we are sabotaging a vast, powerful, invisible ecosystem on whose health our own depends. A biospheric matrix is dying. The angels weep.
Published 4th September 2015