Interesting to see one of my story ideas is also an Earthshot prizewinner this year.
On the planet Rehome I had a new company make a replacement for cardboard boxes from kelp (a type of seaweed), dealing with the way to make the material hard and not susceptible to taking in moisture. The real company has partnered with a seaweed company, while I had the local fishermen add kelp harvesting to their other tasks.