Fin whales in front of the iceberg on Elephanta Island Photo by Dan Beecham
Nature-based solutions to climate change have adopted holistic approaches that promote biodiversity and ecosystem conservation. While many efforts have focused on planting trees or restoring wetlands, researchers believe it is also important to understand the carbon sequestration potential of the largest animals on Earth, whales. They explored how these ocean giants affect carbon levels in the air and water, as well as contribute to the overall reduction of atmospheric carbon dioxide. The paper was published Dec. 16 in Trends in Ecology and Evolution.
“Understanding the role of whales in the carbon cycle is a dynamic emerging area that could benefit ocean conservation and climate change strategies.” The team of authors, led by Heidi Pearson, a biologist at the University of Alaska Southeast, wrote, “This requires interdisciplinary collaboration between marine ecologists, oceanographers, biogeochemists, carbon cycle modelling experts, and economists.” ”
Whales can weigh up to 28 tons, live more than 100 years, and are the size of large aircraft. Like all living things, their enormous biomass is mostly made up of carbon, and researchers believe whales may be the largest biocarbon pool in the ocean, responsible for storing 22 percent of Earth’s total carbon.
“Their large size and long lifespan allow whales to have a powerful impact on the carbon cycle because they can store carbon more efficiently than small animals, and whales can absorb a lot of prey and produce a lot of waste.” “Given that baleen whales are among the longest migrating whales on Earth, they may influence nutrient dynamics and carbon cycling at the ocean basin scale,” the authors wrote. ”
The whales consume krill and photosynthetic plankton for 4% of their body weight every day. For a blue whale, this equates to nearly 8,000 pounds. When food is digested, their excrement is rich in important nutrients that help krill and plankton reproduce, help increase photosynthesis and carbon storage in the atmosphere.
For example, blue whales can live up to 90 years. After death, when their bodies sink to the bottom of the sea, the carbon contained in them is transferred to the deep sea as they decay. This complements the biocarbon pump, where nutrients and chemicals are exchanged between the ocean and atmosphere through complex biogeochemical pathways. Commercial hunting, the largest source of whale population decline, has reduced whale populations by 81 percent, but its impact on biocarbon pumps is unknown.
“Whale recovery may contribute to the long-term self-sustainment and enhancement of ocean carbon sinks,” the authors wrote. The full role of whales and other organisms in reducing CO2 can only be realized through strong conservation and management interventions that directly contribute to the growth of whales and other organisms. (Source: Feng Weiwei, China Science News)
Related paper information:https://doi.org/10.1016/j.tree.2022.10.012