Researchers Create a Family History of San Diego Kelp over More Than Four Decades

by Robert Monroe, UC San Diego Scripps Institution of Oceanography
March 5, 2026

The growth form of giant kelp (Macrocystis pyrifera) is composed of shoots known as stipes instead of branches. From one parent holding fast to the hard bottom might come as many as 150 stipes. 

Typically the tips of the biggest kelp bob at the ocean surface and calm the waters, appearing as patches of gold visible from land — a sign of the good health of the ecosystem that it anchors.

But the kelp as San Diego knows it is in trouble. 

In January, a team led by UC San Diego’s Scripps Institution of Oceanography released an unmatched history of kelp forests off La Jolla and Point Loma. Together spanning nearly 19 square kilometers (7.3 square miles), they are the largest on the United States West Coast. Amassed over more than 40 years, their story reveals a progression of steady decline that transcends typical cycles of crash and recovery. 

Keep reading: https://scripps.ucsd.edu/news/researchers-create-family-history-san-diego-kelp-over-more-four-decades

Read the Ecological Applications paper: https://esajournals.onlinelibrary.wiley.com/doi/10.1002/eap.70181