The Marine Carbon Cycle Explained

Picked one by one from a mixed channel. Transcript check: both title readers certain; 4 of 5 sampled certain picks confirmed by transcript, none failed. Channel rule: Include only the narrated natural-history documentaries and explainers (e.g. Into the Abyss films, Midnight Zone segments, Coral Triangle, Deep Sea Gigantism, Whale Decomposition, Siphonophores, What Is An Ecosystem), and exclude sleep/relaxation editions, childhood fact files and pet-care clips, 'cute'/'up close' footage, personal pet videos and 'Weird Animal Facts' hook titles.