Sargassum Season Begins: What You Need to Know About Quintana Roo’s Seaweed Alert

Sargassum Returns to the Shores of the Riviera Maya: What to Expect in 2025

Sargassum season has officially begun in the Riviera Maya, with the first patches of seaweed washing up on the beaches of Solidaridad, Quintana Roo. According to Estevan Amaro, director of the Quintana Roo Sargasso Monitoring Network, the annual arrival of this floating macroalgae is expected to intensify in the coming months, peaking between May and August.

Why Does Sargassum Arrive?

Sargassum is a naturally occurring seaweed that originates in the Sargasso Sea, a vast region of the Atlantic Ocean. Historically, small amounts of sargassum would drift to Caribbean shores, but in the last decade, massive blooms have become a seasonal problem.

Scientists link this surge to climate change, rising ocean temperatures, and excess nutrients in the water from agricultural runoff and river systems in Africa and North America. When combined with high solar radiation, these factors create the perfect conditions for explosive sargassum growth.

Sargassum and the Riviera Maya

Before 2011, sargassum arrivals in the Riviera Maya were rare and manageable. However, in recent years, the phenomenon has become an ongoing challenge for the region. While some seasons have been lighter than others, 2018 and 2019 saw record-breaking amounts of sargassum, covering beaches from Cancún to Mahahual.

In the past two years, ocean currents have diverted much of the seaweed toward Caribbean islands like Puerto Rico, Cuba, and the Dominican Republic, reducing its impact on Mexico’s shores. There is hope that this trend will continue in 2025, but experts warn that conditions could shift at any time.

Where Is Sargassum Expected to Accumulate?

The Quintana Roo Sargasso Monitoring Network closely tracks areas known as “red foci,” or high-risk zones. These include:

• Cozumel
• Tulum
• The southern zone of Punta Nizuc (bordering Puerto Morelos)
• Mahahual, which has historically seen some of the highest accumulations

Potential Risks and Precautions

Sargassum not only affects the beauty of the beaches but can also pose health risks. As it decomposes, the seaweed releases gases such as carbon dioxide, hydrogen sulfide, and ammonia. While generally not harmful in small amounts, high concentrations can cause respiratory irritation, particularly for those with asthma or other breathing conditions.

Amaro also advises caution when handling sargassum, as the liquid produced during decomposition may contain skin-irritating toxins. Proper cleanup methods are essential to minimize health risks and environmental damage.

Looking Ahead

While there is optimism that sargassum levels will remain moderate this year, experts will continue monitoring its movement closely. Beachgoers and businesses along the Riviera Maya should stay informed and prepared for potential fluctuations in seaweed arrivals.

Despite the challenges, the region remains committed to addressing the sargassum issue, using barriers, collection efforts, and innovative solutions to keep beaches as clean as possible for both residents and visitors.