On June 9, 2025, visitors to Playa Algodones in San Carlos, Sonora, encountered patches of floating brown seaweed washed ashore. Although sargassum more commonly impacts beaches along Mexico’s Caribbean coast, seasonal currents and rising sea temperatures occasionally carry it into the Sea of Cortez.
Sargassum is a free-floating marine alga that naturally forms large mats in open waters. In the pelagic zone, these mats serve as critical habitats and nurseries for fish, crustaceans, and sea turtles. However, when currents drive excessive amounts toward shore, the algae decompose, releasing an unpleasant odor, discolouring the water, and creating matted piles that interfere with swimming and sunbathing.
Beach strandings of sargassum typically spike between April and October. During this period, warmer water boosts algal growth while shifts in currents and nutrient levels can steer blooms toward the coast. Even though San Carlos does not experience the same intensity of influx seen on eastern beaches, its appearance on Playa Algodones is not unprecedented and follows familiar oceanographic patterns.
A recent site inspection at Playa Algodones confirmed visible sargassum lines along the high-tide mark. Though less severe than Caribbean outbreaks, the seaweed presence prompted some beachgoers to choose cleaner sites. Local tour operators and lifeguards assured visitors that the blooms arrive in cycles and that crews will rake and remove the algae within days to restore the beach’s usual appeal.
For those looking to avoid sargassum entirely, San Carlos offers alternatives. Playa Caracol and the smaller coves of the fishing village La Manga showed no signs of seaweed accumulation during the June survey. Their sheltered bays and differing current patterns make them reliable choices for a seaweed-free day at the shore.
Local authorities continue to monitor sargassum movements using satellite imagery and reports from beach patrols. Tourism officials encourage visitors to check live beach-condition feeds before planning outings and to support cleanup efforts by disposing of collected seaweed in designated bins rather than leaving it to decompose in public areas.
As summer progresses, residents and tourists alike will keep an eye on shifting tides. While sargassum in San Carlos remains a temporary nuisance, its predictable seasonality and the availability of nearby clean stretches of sand ensure that Mexico’s Pacific shoreline retains its draw for sunseekers and swimmers alike.
On June 9, 2025, visitors to Playa Algodones in San Carlos, Sonora, encountered patches of floating brown seaweed washed ashore. Although sargassum more commonly . . .
