It’s a method called ‘sea-weeding’ and it has fuelled an increase in coral recovery of up to 600%. It’s the same principle as weeding a garden and it’s neither high-tech nor expensive, which could make it ideal for use in developing and small island nations. Since 2018, volunteer divers have been removing seaweed by hand from 2 degraded sites on the Great Barrier Reef. The weeded areas showed significant coral regrowth and an increase in coral diversity.