Baleen whale consumption is re-measured, and the krill paradox sharpens
High-resolution foraging measurements find that earlier work underestimated baleen whale prey consumption by threefold or more in some ecosystems. Pre-whaling Southern Ocean baleen whales are estimated to have eaten around 430 million tonnes of Antarctic krill a year - about twice the current estimated standing biomass of the species. The same work estimates iron recycling by Southern Ocean baleen whales at around 1.2 x 10⁴ tonnes a year before whaling against 1.2 x 10³ tonnes today, offering a mechanism for why krill declined rather than increased after the whales were removed.
Historical — it happened, and the record is settled.
Subjects
- Whale-Mediated Iron Recycling · ecological phenomenon · Southern Ocean and other baleen whale feeding systems · not located
- Antarctic Krill (Euphausia superba) · species · Southern Ocean - circumpolar, south of the Antarctic Polar Front · not located
- Southern Ocean · maritime region · Circumpolar, south of roughly 40°S · not located
- Blue Whale (Balaenoptera musculus) · species · Global ocean, all major basins · not located
Evidence
Partly verified — Core facts are sourced; some optional detail is deliberately absent.
Baleen whale prey consumption based on high-resolution foraging measurements
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.
Nature; Savoca and colleagues · 2021-11 · Partly verified
Nature; doi:10.1038/s41586-021-03991-5; https://www.nature.com/articles/s41586-021-03991-5
Recorded on Whale-Mediated Iron Recycling
- The longest blue whale on record is measured at South Georgia
- The factory ship Lancing takes a stern slipway south
- The Antarctic blue whale catch reaches its all-time peak
- The heaviest blue whale on record is weighed
- The IWC protects blue whales from commercial hunting
- CCAMLR is agreed at Canberra
- The commercial whaling moratorium takes effect
- The Southern Ocean Whale Sanctuary is adopted
- A long-term decline in krill density is linked to winter sea ice
- The energetics of blue whale lunge feeding are modelled
- Dedicated Antarctic Blue Whale Project voyages
- CCAMLR adopts the Ross Sea marine protected area
- Baleen whale consumption is re-measured, and the krill paradox sharpens
- The only published Antarctic blue whale satellite tracks are released as data
- Antarctic sea ice reaches a record low, a year after the previous one
- Antarctic meltwater is projected to slow the abyssal cell
- A physics-based early warning signal is proposed
Related
Related because they share a subject in the Atlas — never because the text looks similar.
- A physics-based early warning signal is proposed · 2024-02
- The only published Antarctic blue whale satellite tracks are released as data · 2023
- Antarctic sea ice reaches a record low, a year after the previous one · 2023-02
- Antarctic meltwater is projected to slow the abyssal cell · 2023
- CCAMLR adopts the Ross Sea marine protected area · 2016-10
- Dedicated Antarctic Blue Whale Project voyages · 2013, 2015, 2019
- The energetics of blue whale lunge feeding are modelled · 2011
- A long-term decline in krill density is linked to winter sea ice · 2004