California Sea Grant College Program

Fifty years ago, the Southern California kelp forests, arguably one of the richest marine ecosystems on the planet, were home to a remarkable number of large fish and invertebrates. Four-hundred pound black sea bass, 100-pound groupers, 20-pound lobsters swam through the kelp’s towering fronds, sometimes in great numbers.

The absence of once common marine organisms, especially the scarcity of the largest ones, has prompted marine scientists Paul Dayton and Ed Parnell of Scripps Institution of Oceanography and others to describe Southern California’s kelp forest as a veritable “ghost forest.” Their interest in reversing the trend toward greater depletion of these habitats has led them to study the use of marine protected areas as a tool for restoring marine biodiversity.