DNER evaluates seaweed on US beaches

Recently, many coastal municipalities have recorded sargassum concentrations at all-time highs for this century.

By The Star Staff

The Specialized Sargassum Division of the Department of Natural and Environmental Resources (DNER) acted on Monday in response to the significant accumulation of sargassum along U.S. territory beaches.

High concentrations of seaweed have impacted the beaches of Sardinera in Fajardo, Condado, the San Juan Bay entrance, Escambrón, and the U.S. Coast Guard docks. Additionally, officials are conducting assessments in Río Grande and other coastal towns, as announced by Department of Natural and Environmental Resources (DNER) Secretary Waldemar Quiles.

To accurately gauge the volume of this unprecedented sargassum event and to evaluate wind conditions, a drone will be deployed over the affected areas of Río Grande. This critical information will be shared with municipal administrations to develop a robust action plan.

“We are confronting an unprecedented sargassum event in Puerto Rico’s modern history. Recently, many coastal municipalities have recorded sargassum concentrations at all-time highs for this century. In response, our personnel from the Specialized Sargassum Division will commence removal operations in the Sardinera area of Fajardo. Teams have also been dispatched to various locations in San Juan to evaluate the situation, and we will coordinate closely with Coast Guard leadership to maximize our efforts,” the Secretary stated in a written announcement.

“According to research from the University of Central Florida and recent data from the Environmental Protection Agency (EPA), over 40 million metric tons of sargassum are expected to flow through the tropical Atlantic, surpassing the previous record of 38 million tons. Since January, our personnel have been proactively addressing this sargassum season, and we are treating this issue with the urgency it demands,” Quiles emphasized.

“I strongly urge the mayors of the affected municipalities to submit Form 113. Enabled by the executive order signed by our Governor, Jenniffer González, this form allows for the use of public funds to tackle this emergency effectively,” the DNER Secretary concluded.

On July 1, 2025, the Governor signed Executive Order 2025-037, which is designed to streamline processes, ensuring that government agencies can take immediate action to manage the proliferation of this algae and mitigate its impacts. This executive order also provides exemptions to expedite our response to this pressing issue.

Sargassum is a type of brown algae belonging to the genus Sargassum. The EPA describes it as “widely distributed throughout tropical and temperate oceans, in shallow waters and coral reefs, as well as in the open sea.”

According to the environmental advocacy website paralanaturaleza.org, Puerto Rico is currently grappling with the most significant influx of these floating algae recorded this year. Julio Morell, a seasoned professor in the Department of Marine Sciences at the University of Puerto Rico’s Mayagüez Campus (RUM), remarked that this challenging event began unfolding around the weekend of June 11 and is still in progress. He noted that satellite imagery continues to reveal vast quantities of this macroalgae lingering in the Atlantic waters. Historically, the peak season for sargassum in the Caribbean typically spans from July to August.

The exact reasons behind this dramatic surge of sargassum remain somewhat enigmatic. However, experts speculate that various contributing factors, including agricultural runoff, elevated water temperatures, and fluctuations in wind patterns, ocean currents, and rainfall, might be exacerbating the phenomenon, as highlighted in reports by The Guardian.

Looking ahead, predictions indicate that 2025 could set a daunting record for sargassum accumulation in the Atlantic, with scientists anticipating a staggering 40% increase compared to the previous high noted in 2022. This development poses a significant environmental challenge for the Caribbean region. Puerto Rico’s coastlines are already experiencing the repercussions: since mid-May, popular beaches such as Playa Santa in Guánica and Punta Santiago in Humacao have reported significant sargassum build-up, creating discomfort for both residents and visitors alike