Great Lakes Food Web
Freshwater
North America — United States and Canada border
Description
The Laurentian Great Lakes contain 21% of the world's surface freshwater and support a food web dramatically altered by invasive species. Sea lampreys, alewives, and zebra mussels have restructured trophic relationships, while stocking programs have introduced Pacific salmon as top predators. Native lake trout populations are slowly recovering.
Trophic Pyramid
Level 5
Decomposers
Benthic bacteria
Freshwater fungi
Chironomid larvae
3 species
Level 4
Tertiary Consumers
Chinook salmon
Lake trout
Sea lamprey
3 species
Level 3
Secondary Consumers
Yellow perch
Walleye
Smallmouth bass
3 species
Level 2
Primary Consumers
Zebra mussels
Diporeia amphipod
Alewife
3 species
Level 1
Producers
Diatoms
Cladophora algae
Phytoplankton
3 species
Apex Predators
Tertiary Consumers
Secondary Consumers
Primary Consumers
Producers
Key Interactions
- Zebra mussels filter phytoplankton, increasing water clarity but redirecting energy to benthos
- Sea lampreys parasitize lake trout and salmon as ectoparasitic predators
- Alewife invasion restructured the pelagic food web and suppressed native species
- Chinook salmon stocking provides top-down control on alewife populations