Read the full article at - http://www.bbc.com/news/science-environment-35126133
Australian researchers are encouraging people to buy "underwater Christmas trees" to help restore seaweed that suddenly disappeared in the 1980s.
Poor water quality was blamed for the loss of crayweed from 43 miles (70km) of coastline around Sydney.
But as the water quality has improved, scientists are now replanting the seaweed that provides a vital habitat and food for marine life.
Scientists expect the replanted seaweed to recolonise the shallow, rocky reefs.
"These forests of seaweed are very important, not only because they provide important habitats and food for many little creatures, some of which are commercially very important, they can also sequester a significant amount of carbon," explained project leader Ezequiel Marzinelli, a senior research associate at the University of New South Wales.