Key Idea.
Section 1
The Glacier Sea Rivals
Analyzing the full food web reveals that Moon Jellies and Walleye Pollock are in competition. They both eat zooplankton.
This means any change to the Pollock population will indirectly affect the Jellies by altering the availability of their shared food.
Section 2
The Cascade Effect
Evidence shows the Walleye Pollock population collapsed. This is a trophic cascade.
With fewer Pollock eating zooplankton, the zooplankton population increased. This surplus of food allowed the Moon Jellies to reproduce more. Thus, the decline of a competitor indirectly caused the jelly explosion.
Expand to review the lesson summary and core properties.
Section 1
The Glacier Sea Rivals
Analyzing the full food web reveals that Moon Jellies and Walleye Pollock are in competition. They both eat zooplankton.
This means any change to the Pollock population will indirectly affect the Jellies by altering the availability of their shared food.
Section 2
The Cascade Effect
Evidence shows the Walleye Pollock population collapsed. This is a trophic cascade.
With fewer Pollock eating zooplankton, the zooplankton population increased. This surplus of food allowed the Moon Jellies to reproduce more. Thus, the decline of a competitor indirectly caused the jelly explosion.