The recovery of orcas (killer whales), an apex predator in
coastal waters of Alaska, dramatically decreased populations of sea
otters, their most common prey. The decrease in sea otter
population size resulted in an upsurge in sea urchin populations,
which subsequently decreased kelp density and reduced the density
of the many species that live in kelp forests. What is this series
of events an example of?
A. Trophic efficiency
B. Ecosystem engineering
C. Secondary succession
D. Trophic cascade
E. Primary succession