Innovator makes entire house out of Sargassum bricks

Meet Omar Sánchez Vázquez, a nursery owner in Puerto Morelos, Mexico. Recently Omar built an entire house made from seaweed bricks.

Sargassum is a brown seaweed that has recently exploded in abundance and has taken over beaches and even ports throughout Mexico. The seaweed boom is attributed to warming waters and nutrient runoff from onshore agriculture. The problem has gotten so bad that hotel chains have spent millions to clean the beaches and the Mexican navy has started “attacking” the massive rafts of Sargassum out at sea. Where most people saw the Sargassum as a problem Omar saw an opportunity. He designed an organic, thermal and functional construction material. The same technique used to make adobe bricks is used to make Sargassum bricks, however, the Sargassum bricks are 50% cheaper than adobe. Omar claims these Sargassum bricks are hard enough to withstand a hurricane. And in case you were wondering, the bricks don’t smell like rotting seaweed says Omar in an interview.

New study shows promise that Sargassum sp. improves blood biochemistry profiles

Marine algae have anti-oxidant, anti-inflammatory, antidiabetic, and anti-cancer potential. Sargassum sp. is a type of brown algae that possess pharmacological properties, such as anti-oxidant, anti-inflammatory, anti-hypertensive, anti-bacterial, and anti-viral activities. These pharmacological properties are a result of the biological activity of metabolites such as alkaloids, steroids, terpenoids, saponins, polyphenols, phlorotannin, and fucoidan.

In a recent study, researchers used a rat model to assess treating in vivo stress (swimming model) with Sargassum by measuring levels of glucose, triacylglycerol, total cholesterol, and cortisol, and liver histopathology.

The results were very promising. Rats fed Sargassum (450 mg/kg) has similar results as when treated with diazepam (0.18 mg/kg). The Sargassum treatment improved blood glucose, triacylglycerol, total cholesterol, and cortisol levels and liver histology by decreasing the severity of inflammation.

This news couldn’t come at a better time. Sargassum is currently overrunning beaches due to ocean warming and eutrophication. Even better, this study simply used dry powdered Sargassum. There were no costly extraction methods, meaning anyone simply eating Sargassum could potentially benefit.

This work was published in the journal of Preventive Nutrition and Food Science.

Sodium alginate from Sargassum sp. used as fruit preservation coating

Researchers from Hasanuddin University may have found a new use for the seaweed Sargassum. Alginate, a natural sugar found in some seaweeds, can be used as an ingredient to make edible packaging or better known as an edible film or edible coating. Edible coatings have been used to protect food products while maintaining the original appearance of the product.

The researchers focused on extracting sodium-alginate from Sargassum to use as an edible coating to preserve fruit, in this case, mango. The study used increasing concentrations of Na-alginate (0-50 ppm) solutions to bathe the mango in. They found that at 20 ppm the shelf-life at room temperature was tripled to 15 days compared to the control 0 ppm solution, which only lasted 5 days (see table below).

This could be a powerful use for the tons of Sargassum washing up in various parts of the world, and aid in future food security by eliminating produce waste.

The study was published in Indonesia Chimica Acta and can be read here

What will Mexico do with all that sargassum?

Due to climate change and nutrification of coastal environments, algal blooms are becoming more frequent and exaggerated. Algal blooms are typically in reference to microalgae, however, there can be blooms of macroalgae as well. For example, right now over 100 million tons of Sargassum are headed to the Mexican shores. For many coastal industries, this is a big problem, harbors become blocked and resort beaches become deserted. That’s why President López Obrador is bringing out the big guns, the Mexican Navy. The help is coming after an outcry of resorts failing to keep the beaches clear. The Cancún-Puerto Morelos hotels association has estimated that cleaning the beaches of sargassum will cost at least 700 million pesos (US $36.7 million) this year.

It’s unclear what the Navy has planned for 100 million tons of seaweed, our guess is to throw it all in a landfill. One thing is clear, any entrepreneurs that figure out how to make that seaweed into a revenue stream will become extremely wealthy. Hotel chains are already willing to pay millions for someone to take it away. There is opportunity for production of, fertilizers, nutraceuticals, protein, or cosmetics.

Read an article about the Mexican navy involvement here