Seaweed

Once a harmless drifter in the Sargasso Sea, an algae known as sargassum is now flooding beaches, from Brazil to the Caribbean, with stinky piles. But some clever researchers have mixed it into concrete creating a new, ultra-light building material.

Seasteading proponents envisage a floating society with a fluid geography, free from oppressive government in international waters. But they'll need something to build their watery utopia on top of, and these interlocking seaweed bricks might be it.

While the farming of salmon does help take pressure off wild stocks, the feed used to raise the fish still isn't entirely sustainably sourced. That may change, however, thanks to nutrient-rich worms that eat readily available seaweed.

Sargassum seaweed is growing out of control in many regions – it washes up on beaches in huge amounts. Utilizing a new technique, that rotting organic matter could soon be converted into biofuels and other products.

18th century residents of a small island in Denmark called Læsø didn't have enough resources to top their houses with thatched or wooden roofs. Being practical types, they used what they did have in abundance: seaweed.

Danish architectural firm has Vandkunsten partnered with non-profit organization Realdania Byg to create the Modern Seaweed House. Located on the small island of Læso in Denmark, the holiday home features a simple wooden structure covered with a layer of insulating seaweed.