El Niño Expected to Bring Severe Coral Bleaching and Sargassum Surge to Quintana Roo

Cancún, Quintana Roo — Warming Caribbean waters are set to trigger severe thermal stress on coral reefs, accelerate sargassum blooms, and reduce catches of key fish species, according to a new study by Mexican researchers.

Sea surface temperatures off Quintana Roo have already risen from 27°C to 29°C and are forecast to reach 30°C in the coming weeks, said Esteban Amaro Mauricio, a hydrobiologist involved in the study.

The findings come from the “Diagnosis of the Effects of Climate Change on the Coast” project, launched in September 2025, which tracks changes along the state’s coastline.

“In the coming fishing cycles, we will see significant declines in lobster, shrimp, and sport fish species, while bleaching will continue on the second-largest reef in the world, along with ongoing beach erosion,” Amaro said.

The impacts are linked to an extreme El Niño event colloquially called “Godzilla El Niño,” characterized by major temperature anomalies in the equatorial Pacific, according to researchers from UNAM’s Institute of Marine Sciences and Limnology. The phenomenon disrupts global climate patterns, reducing upwelling of cold, nutrient-rich waters and expanding low-oxygen zones in the ocean.

Scientists anticipate a higher risk of mass coral bleaching from thermal stress, a notable drop in catches of species vital to the local economy, and ideal conditions for massive sargassum arrivals on Mexican Caribbean beaches — an influx already being experienced.

Accelerated coastal erosion, with sand loss, and possible declines in fish, bird, and other marine populations are also expected. Warmer waters will speed sargassum growth and its mass arrival on shores, potentially harming the tourist image of beaches in Cancún, Playa del Carmen, and Tulum, while increasing coastal erosion and damaging reefs by blocking sunlight and altering water chemistry.

Coral bleaching could accelerate further, affecting fish, sea turtles, and seabirds, as well as the diving and snorkeling tourism that is a pillar of Quintana Roo’s economy.

Beyond marine effects, the monitoring predicts more frequent rainfall in the Yucatán Peninsula through the end of the year. Although the region’s karst soil absorbs water quickly, these patterns could affect infrastructure and local agriculture.

Amaro said state and federal authorities are maintaining constant surveillance using satellite imagery and fieldwork to anticipate and mitigate impacts on tourism, fishing, and coastal ecosystems. The monitoring continues and will be updated as ocean conditions evolve.