Seaweed serves as an excellent carbon sink, ... nets held together by buoys float in the ocean. ... pesticides, or soil in order to grow, seaweed has been called a “zero-input” food.

Seaweed along coastlines already captures an estimated 173 million metric tons of CO2 each year as it grows; some of that seaweed eventually sinks, trapping the carbon at the bottom of the ocean.

The seaweed tends to bob around in island-like masses that can stretch for miles. Out in the open ocean, these massive rafts can be key floating habitats that provide food, shelter and breeding ...

As long as seaweed can float it will stay alive, but deposited on a beach above the tide line seaweed will start to die and decay, which can be a problem for beach-goers.

Scientists say the raft resulted from an underwater volcanic eruption near Tonga this month, and it is slowly floating toward Australia. A giant raft of floating rock is not all that uncommon.

Scraping the smelly sargassum seaweed off some beaches on Mexico’s resort-studded Caribbean coast has become not only a nightmare, but possibly a health threat, for the workers doing it.