Whale-Mediated Iron Recycling

Assembled from 34 blocks · 1 evidence · 53 related

1. Story
2. The mechanism behind the krill paradox - the observation that removing the great whales did not leave more krill behind, it left less. Baleen whales feed at depth on iron-rich krill and defecate at the surface, returning iron to the sunlit layer where phytoplankton, the krill's own food, can use it. The 2021 consumption study estimates that Southern Ocean baleen whales recycled around 1.2 x 10⁴ tonnes of iron a year before whaling, against around 1.2 x 10³ tonnes a year today. On that reading the whales were not simply consumers of a krill stock but a large part of what kept it fertilised, and the ecosystem that was left after whaling was not the same ecosystem minus whales.
3. Knowledge
4. Blue Whale (Balaenoptera musculus)
5. Seasonal Krill Aggregation
6. Whale-Mediated Iron Recycling
7. Connections
8. Seasonal Krill Aggregation
9. Blue Whale (Balaenoptera musculus)
10. Baleen whale consumption is re-measured, and the krill paradox sharpens
11. Antarctic Summer Feeding Migration
12. Point Conception
13. California Current System
14. Southern Ocean
15. Rorqual Lunge Feeding
16. Whale-Mediated Iron Recycling
17. The energetics of blue whale lunge feeding are modelled
18. Antarctic Krill (Euphausia superba)
19. Rorqual Lunge Feeding
20. Antarctic Blue Whale (B. m. intermedia)
21. Pygmy Blue Whale (B. m. brevicauda)
22. Northern Indian Ocean Blue Whale (putative B. m. indica)
23. Fin Whale (Balaenoptera physalus)
24. Whale-Mediated Iron Recycling
25. Vessel Collision with Large Whales
26. The longest blue whale on record is measured at South Georgia
27. The heaviest blue whale on record is weighed
28. The IWC protects blue whales from commercial hunting
29. The commercial whaling moratorium takes effect
30. Blue whale song frequencies are observed falling worldwide
31. The energetics of blue whale lunge feeding are modelled
32. Baleen whale consumption is re-measured, and the krill paradox sharpens
33. Evidence
34. Earlier work underestimated baleen whale prey consumption by threefold or more in some ecosystems; pre-whaling Southern Ocean mysticetes are estimated to have consumed about 430 million tonnes of Antarctic krill a year, roughly twice the current estimated standing biomass of the species; estimated iron recycling by Southern Ocean mysticetes was about 1.2 x 10^4 tonnes a year before whaling against about 1.2 x 10^3 tonnes a year today. V55 verification basis: the krill and iron figures were retrieved in search summary attributed to the paper; the frequently quoted "16 tonnes a day" per blue whale came from general-audience reporting and is not asserted as a figure in this pack.