Abstract

We developed new techniques for restoring and protecting giant kelp, Macrocystis pyrifera, forests in southern California using artificial kelp plants constructed of plastic. The blades of these artificial plants sweep across the substrate creating a whiplash effect similar to that reported in natural kelp populations in Chile and southern California. The artificial plants reduced the density of purple sea urchins, Strongylocentrotus purpuratus, by almost 85% and red sea urchins, S. franciscanus, by 75% in sea-urchin-dominated areas. Artificial plants effectively protected giant kelp transplants that were placed in sea-urchin-dominated areas.