Whales can weigh up to 150 tons, live over 100 years, and be as big as large airplanes. Composed largely of carbon, they make up one of the largest living carbon pools in the pelagic ocean, part of the marine system responsible for storing 22% of Earth’s total carbon. Whales consume up to 4% of their massive body weight in krill and photosynthetic plankton daily. Their excrement is rich in important nutrients helping krill and plankton flourish, aiding in increased photosynthesis and carbon storage. When whales die and decay, the carbon they contain transfers to the deep sea. Commercial hunting, the largest source of population decline, has decreased whale populations by 81%, with unknown effects on biological carbon pump. We need to keep the remainder alive.
https://www.cell.com/trends/ecology-evolution/fulltext/S0169-5347(22)00279-8