Biology
Trophic Cascades and Keystone Predation in Marine Kelp Forest Ecosystems
Quick fact
Sea otters, by preying on sea urchins, trigger a trophic cascade that protects kelp forests. In areas where otters are absent, sea urchins can overgraze kelp, creating barren reefs with drastically reduced biodiversity.
Why this is interesting
In the cold waters of the North Pacific, a floating forest of giant kelp hides a delicate balance of power—where a single furry predator can hold back an army of spiny herbivores. But when that predator disappears, the entire underwater forest can vanish in a matter of months. What happens when one species holds the fate of an entire ecosystem?