Removing top predators like sea otters triggers reciprocal population changes down the food chain, causing dramatic shifts in ecosystem structure.

Evidence

Trophic cascade | Definition, Importance, & Examples (Britannica)

Categorization

• corroborated: 2 independent passages support this claim
• XREF: connects to: Extreme misfortune can have cascading negative effects on families. — Crews, Harry, A childhood the biography of a place, 21