Southern Ocean Krill-Centered Food Web
Marine
Southern Ocean — circumpolar around Antarctica
Description
Antarctic krill biomass is estimated at 300-500 million tonnes, making them possibly the most abundant wild animal species by mass. This food web revolves around krill as the central node connecting primary production to virtually all Southern Ocean predators. Climate-driven sea ice decline threatens krill recruitment and cascading effects through the entire ecosystem.
Trophic Pyramid
Level 5
Decomposers
Cold-water bacteria
Amphipod scavengers
Benthic isopods
3 species
Level 4
Tertiary Consumers
Orca
Leopard seal
Sperm whale
3 species
Level 3
Secondary Consumers
Emperor penguin
Antarctic petrel
Minke whale
3 species
Level 2
Primary Consumers
Antarctic krill
Ice krill
Copepods
3 species
Level 1
Producers
Ice-edge phytoplankton
Diatom blooms
Sea ice algae
3 species
Apex Predators
Tertiary Consumers
Secondary Consumers
Primary Consumers
Producers
Key Interactions
- Krill swarms can extend for kilometers and contain billions of individuals
- Emperor penguins dive to 550 meters and hold their breath for 22 minutes to catch krill and fish
- Industrial krill fishing for aquaculture feed competes with natural predators
- Juvenile krill shelter under sea ice and graze on ice algae during winter