Ochre Sea Star

The ochre sea star is where keystone species theory began. In 1966, ecologist Robert Paine removed sea stars from a stretch of Washington coastline and watched the ecosystem transform. Without sea star predation, mussels took over, smothering algae and excluding other species. The rocky intertidal shifted from diverse community to mussel monoculture. A single predator's presence determined whether the ecosystem existed in one stable state or another.

This original keystone experiment established principles that apply to kelp forests and beyond. Pisaster doesn't eat kelp - it eats mussels on rocks. But by preventing mussel domination, it maintains the substrate diversity that allows multiple species to coexist. Remove the keystone and competitive exclusion collapses diversity into monoculture. The keystone species maintains a stable state that wouldn't exist without active intervention.

For business, Pisaster represents the foundational insight that active intervention can maintain market states that wouldn't persist naturally. Antitrust enforcement prevents monopoly monocultures. Platform moderation prevents toxic community takeover. Quality standards prevent race-to-the-bottom degradation. Without these keystone functions, competitive dynamics drive toward dominant-player equilibria. The ochre sea star teaches that diversity and dynamism often require active maintenance - they're not natural states that persist without effort.