Adélie Penguins Dive Deeper for Krill in 6,000 Dives as Study Challenges Depletion Theory
Updated
Updated · Earth.com · Jul 16
Adélie Penguins Dive Deeper for Krill in 6,000 Dives as Study Challenges Depletion Theory
3 articles · Updated · Earth.com · Jul 16
Summary
Data from 30 foraging trips and more than 6,000 dives showed Adélie penguins had to dive progressively deeper and swim farther to reach krill, even though feeding success stayed steady once prey were encountered.
That pattern points to reduced prey accessibility rather than outright prey loss: repeated diving from the same narrow sea-ice openings likely pushed krill deeper or sideways without thinning the patches themselves.
The study tracked 23 penguins at East Antarctica's Hukuro Cove, where a colony of 217 breeding pairs foraged through crowded cracks in landfast sea ice, letting researchers reconstruct underwater dive paths in 3D.
The findings challenge the standard explanation for Ashmole's halo around seabird colonies, suggesting long or deep dives can reflect hidden but still-present prey and could alter how scientists judge Southern Ocean ecosystem health.