Even moderate heat waves depress sea urchin reproduction aling the Pacific coast

Submitted by Mariana Padilla on Fri, 11/14/2025 - 15:14

An orange Garibaldi floats above a field of purple sea urchins, which have proliferated along the California coast and in boom years often decimate kelp forests. Understanding the causes of urchin boom and bust cycles can help biologists plan mitigation measures that preserve a balanced coastal ecosystem. Photo Credit: Ron McPeak, courtesy of the Santa Barbara Coastal Long Term Ecological Research Program

Biologists believed that urchin reproduction along the Pacific Coast would only be affected by marine heat waves at lethal ocean temperatures, a new study conducted by IB Assistant Professor Daniel Okamoto and other marine biologists at UC Berkeley suggests that this threshold of susceptibility, for urchins and other marine species, may be at lower temperatures than previously thought. Read the full article here.