July 17, 2025 — Across the globe, oceans are acidifying as they absorb carbon dioxide from the atmosphere, threatening coral reefs and many other marine organisms. A new study, led by oceanographers at the University of Hawaiʻi at Mānoa, revealed that unprecedented levels of ocean acidification are expected around the main Hawaiian Islands within the next three decades.
Increased ocean acidification has the potential to harm marine life by weakening the shells and skeletons of organisms such as corals and clams, amplifying the effects of existing stressors, and threatening ocean-based ecosystems. However, researchers have hope, as some organisms have shown signs of adapting to the changing waters. The study helps researchers, conservationists and policymakers understand the future challenges facing Hawaiʻi’s coral reefs and provides information for preserving these critical ecosystems for future generations.
Researchers within the laboratory group of Brian Powell, professor in the Department of Oceanography at the UH Mānoa School of Ocean and Earth Science and Technology (SOEST), used advanced, fine-scale computer models to project how ocean chemistry around the main Hawaiian Islands might change over the 21st century under different climate scenarios based on how much carbon dioxide societies continue to emit.
“We found that ocean acidification is projected to increase significantly in the surface waters around the main Hawaiian Islands, even if carbon emissions flatline by mid-century in the low emission scenario,” said Lucia Hošeková, lead author of the paper and research scientist in SOEST. “In all nearshore areas these increases will be unprecedented compared to what reef organisms have experienced in many thousands of years.”