A vast belt of brown seaweed twice the length of Australia is inundating the coastlines of Florida and the Caribbean, swamping tourist beaches, strangling fisheries and generating toxic hydrogen sulphide gas as it rots on the shore.

In 2011, a type of algae called sargassum began growing into giant blooms that stretch from West Africa to the Gulf of Mexico. Dubbed the Great Atlantic Sargassum Belt, the 8000 kilometre-long seaweed patch is visible from space.

“Although the peak month of June or July is several months away, there is already a sign that this year’s sargassum bloom will likely be the largest ever recorded, with major impacts throughout the next few months,” reported the University of South Florida’s Optical Oceanography Lab in March.

But as 13 million tonnes of the seaweed wreaks havoc, an Australian entrepreneur plans to convert swaths of the bloom into bioplastic.

Fionnuala Quin founded her start-up, Kelpy, in the depths of lockdown from her home in Jervis Bay. Compelled to do something positive for the planet after Black Summer’s horrific impact on the New South Wales south coast, Quin, the daughter of a fisherman, began researching how to make bioplastics from seaweed.

Other start-ups, such as the CSIRO-backed Uluu, have worked on deriving sugars from seaweed and fermenting them with microbes that produce natural polyesters.

But Quin engaged polymer scientists who have developed an entirely new compostable bioplastic.

“This is a completely different process,” Quin said, who would not reveal more about the technology because it was yet to be patented.