This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: For more than 30 years, MBARI technology has recorded real-time data about Monterey Bay, from oceanographic conditions at the surface to biological surveys in the depths of Monterey Canyon. These data are integral to understanding our changing ocean and underpin the institute's efforts to monitor the impacts of the incoming El Niño, which has been predicted to be among the strongest since the beginning of modern oceanography.
Over the past month, MBARI researchers have detected the first signals of an extreme El Niño reaching Monterey Bay. MBARI moorings have recorded an anomalously strong influx of warm water at depth, while recent MBARI expeditions have observed warm-water species typically found farther south. "The 2026–27 El Niño has been forecast to be one of the strongest ever.
Temperatures measured at an MBARI mooring have confirmed this for Monterey Bay, with the warmest temperatures observed in close to 40 years," said MBARI senior scientist Francisco Chavez, an internationally recognized authority on El Niño. "MBARI scientists have been closely tracking the strengthening El Niño in the equatorial Pacific. Oceanographic data and biological observations now clearly show evidence that a strong El Niño has arrived in Central California." The El Niño Southern Oscillation (ENSO) is a natural climate pattern in the Pacific Ocean with global implications for weather and ocean health.
The atmosphere and ocean are closely linked, and an El Niño event develops when trade winds relax and the Pacific's warmest waters near Asia flow back toward the Americas. The warming of the central and eastern Pacific can increase global temperatures, alter atmospheric patterns, raise sea levels along coastlines and affect marine ecosystems. The Global Ocean Biogeochemistry Array (GO-BGC)—a collaborative initiative led by MBARI scientists Ken Johnson and Yui Takeshita—collects real-time data on ocean health using a global network of hundreds of robotic biogeochemical Argo floats.
Scientists have been monitoring data from GO-BGC floats deployed in the equatorial Pacific to track the developing El Niño. In late September, GO-BGC float data revealed an increase in water temperature, alongside a decrease in concentrations of dissolved carbon dioxide and nitrate, a chemical signature indicating weakened equatorial upwelling. Both are telltale signs of a strengthening El Niño.
The ecological impacts were quickly evident. The equatorial Pacific is typically a region of high plankton productivity, but GO-BGC floats have already logged a sharp decline in chlorophyll concentrations, an indicator of phytoplankton biomass. "The GO-BGC floats show ecosystem properties before El Niño, in the event and after, allowing a direct assessment of ocean change.
Extract — continue reading at the source.
