1 / 13 | Sargassum is once again approaching record levels: which areas of Puerto Rico have received the greatest impact? The total sargassum recorded in June 2026 at the regional level was just 10% below the historical record reached in 2025. – Supplied
While new accumulations of sargasso impact different coasts of Puerto Rico, the total amount of material that arrived on the island in June was just 10% below the historical record reached in 2025, despite the fact that the peak point of the season has not been reached.
Julio Morell Rodríguezexecutive director and principal investigator of the Integrated Coastal Ocean Observation System for the Caribbean (CARICOOS), indicated The New Day that this year could end, at the very least, as the second with the greatest presence of sargassum since records have been kept.
“We are seeing events of the same magnitude as last year”said the chemical oceanographer, pointing out that 2025 represented the largest event recorded so far.
So far, impacts have been reported in areas such as Humacao, San Juan, Ceiba, Culebra and Fajardo, particularly in Las Croabas.
Accumulations have also been observed in Playa Sucia, in Cabo Rojo; Guanica; La Parguera, in Lajas; and sectors of the north coast, from Loíza and Piñones to Levittown.
1 / 13 | This is what the arrival of sargassum to the coasts of Puerto Rico looks like. The total sargassum recorded in June 2026 at the regional level was just 10% below the historical record reached in 2025. – Supplied
Morell indicated that a new pulse of sargassum recently arrived in La Parguera, where the accumulations reached, over a period of one week, an average of between 20 and 30 kilograms per meter of coast.
In Fajardo, one of the areas with the greatest impact, he noted that they have recorded an average of up to 40 kilograms of sargassum per meter of coastline over the course of a week.
The scientist added that the Caribbean Sea recorded record levels of sargassum for the month of June, while in the Gulf of Mexico the amount reached 5 million metric tons, almost double the previous record in that region.
However, he warned that a large amount of the macroalgae still remains in the Atlantic Ocean with the potential to move towards the Caribbean in the coming months.
“The event is just beginning. We are halfway through. Therefore, we expect them to arrive in quantities equal to or greater than those that have arrived in the last two months,” he said.
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In the scientist’s opinion, August and September could mark the period of greatest impact of the season, given the amount of sargassum that still remains in the Atlantic.. The season usually begins between early April and May, and runs until the end of October.
According to Morell, the arrival of sargassum to Puerto Rico does not depend only on the amount found in the Atlantic, but also on ocean currents and, particularly, the direction of the winds.
“The direction of the wind is critical, in addition to the direction of the current,” held.
Because part of the sargassum structure remains on the water surface, the wind can significantly modify its path. Therefore, the areas of greatest impact may vary as atmospheric and oceanic conditions change.
He explained that, during this time of year, the usual absence of northerly winds reduces the probability of sargassum being pushed towards certain areas. However, he warned that wind patterns can vary and be difficult to predict.
The oceanographer maintained that the El Niño event can also significantly alter the patterns. The climate phenomenon is characterized by warmer than normal waters in the Pacific Ocean and stronger westerly winds, conditions that can cause an increase in vertical wind shear.
1/7 | What is El Niño? The meteorological phenomenon that could be “very strong” this year. The El Niño weather phenomenon formed in the tropical Pacific, expected to be “very strong” and bring a “prolonged” period of above-average temperatures. – NOAA
Risks due to large accumulations
Although sargassum represents a valuable habitat for some marine species, large accumulations on coasts can cause negative effects on the environment and health.
When sargassum builds up and begins to decompose, it releases hydrogen sulfide, the gas responsible for the strong odor associated with these events.
“When they smell the smell, it is important that people move away (…) It is not healthy to inhale it,” recommended Morell, who warned that exposure to the gas can represent a health risk.
Macroalgae can also concentrate heavy metals and metalloids present in the ocean, including arsenic, which can be released into the environment during the decomposition process or represent a risk to those who handle large quantities without adequate protection.
1 / 14 | Crisis on the coasts: this is the machine that removes sargassum from the water. The DRNA currently has two aquatic machines for the control of sargassum. – Ramon “Tonito” Zayas
Furthermore, its decomposition can reduce oxygen levels in the water and increase the presence of carbon dioxide, which contributes to acidification and can affect different marine species.
“Wherever there are large accumulations it causes direct and indirect impacts”highlighted the director.