The cozy Mexican homes made from noxious seaweed

“I always wanted to come back to Mexico and live my Mexican dream,” says Omar de Jesús Vazquez Sánchez, who is sometimes nicknamed Señor Sargazo or Mr. Sargassum. “Not the American dream … I wanted to come back and do something for my country.”

Omar is an innovator who saw potential in what others thought was an unsolvable problem – the noxious brown sargassum seaweed that plagues beaches in Mexico and increasingly, North America and the Caribbean. Since 2015, his business, Blue Green, has been turning the seaweed into bricks to build basic but sturdy homes for low income families, even as his business helps support tourism by cleaning the beaches.

His vision is a country where local entrepreneurs create thriving, sustainable businesses that give back to their communities. ‘[I want to] have the best company in Mexico that pays the best salaries. That way people don’t have to cross the border and risk their lives like we did’. Part of that vision is to provide housing for other families – he never had his own home in the US.

In 2015, a year after Omar had returned home to Mexico to set up a gardening business, massive amounts of sargassum began washing up on the shores of the Riviera Maya, and he expanded his business into beach cleanup. As he tells his story:

“Where others saw a problem, I saw an opportunity to turn it into its own sustainable solution, including placing it in service of people who need it the most. I started collecting sargassum seaweed to use as fertilizer for my business, Blue-Green Nursery, and selling it in small amounts to my clients. Soon I obtained permits and within a year was employing about 300 families to clean the beaches for local hotels and resorts.”

“But then it occurred to me that we could turn sargassum seaweed into construction bricks as it was already being used to make products like plates and other things. Inspired by the memory of my family’s little adobe house, I developed Sargablock, an architectural brick made from the sargassum seaweed that spoils our beaches between April and October.”

“I adjusted a machine designed to make adobe bricks so that it can process a mix of 40% sargassum and 60% other organic materials for the Sargablock. The machine can turn out 1,000 blocks a day, and after four hours of baking in the sun, they are dried and ready to be used.”

“After we built Casa Angelita, the first sargassum house named after my mother, Sargablock became one of the first seaweed projects to get off to a solid start in our state of Quintana Roo. From there, I was determined to use sargassum seaweed as a low-cost building material to build affordable housing throughout the Riviera Maya so that families can live in their own homes.”

The problem keeps growing. The state government of Quintana Roo collected 19,000 tons of sargassum from beaches in 2020; 44,000 tons in 2021; and 54,000 tons last year. Researchers say it could nearly double this year, said the Christian Science Monitor. Omar used 3,000 tons of sargassum in  2021, 2,000 tons last year, and by early April 2023, had already used 700 tons.

“Now we have a first artisanal factory in Mahahual, a tourist town where a dock for cruise ships operates, and we are creating jobs. A sargassum house could last 120 years, and we would like to have 10 houses finished by the end of the year, which will be donated to underprivileged families. My vision goes beyond turning a profit; I would like to see a country where local entrepreneurs create thriving, sustainable businesses that give back to their communities.”

“People from countries like Belize, Jamaica, Puerto Rico, the Dominican Republic, Barbados, Malaysia and the United States are contacting us for help in doing what we are doing. They’re all hit harder every day by the seaweed washing up on their beaches. It is maybe nature’s way of telling us to protect our seas. We must be aware of what is happening on the beaches. The sea is very wise and is telling us something. With the contamination we have created over so many years it tells us to take care of what we have.”

A record amount of sargassum is turning crystal blue Caribbean coast waters brown and smelling of rotten eggs as it decomposes in tourist spots from Mexico to Caribbean islands and now along the beaches of Florida’s east coast, the Christian Science Monitor reported earlier this year.

But solutions are blossoming, too. “One of the biggest potential uses lies in demand for so-called alginates, a biomaterial extracted from brown seaweed, which is a common ingredient in food thickeners, wound care and waterproofing agents for its gel-like properties,” Reuters reported in 2021. “The global market in 2020 was worth almost $610 million, a figure that’s expected to grow to $755 million by 2027, according to consulting firm Global Market Insights.”


Sargablock. UN Development Programme, Mexico.

Sea Change – The Mexican Dream. Exposure. Feb. 13, 2020 

In Cancun, this man is turning seaweed trash into natural-building treasures. The World, Jul. 19, 2022 

The world sees invasive seaweed. This gardener sees housing bricks. Christian Science Monitor, Apr. 19, 2023

Besieged by seaweed, Caribbean scrambles to make use of the stuff. Reuters, Sep. 29, 2021

Cover image and other photos by Emily Mkrtichian for UNDP Mexico.