Very warm water makes corals lose tiny living things called algae. These give corals much of their food. Without them, corals turn pale and may die.
Scientists at Stanford University tested ten pairs of coral pieces. Each pair had a pale piece and a healthy copy from the same coral group. Five pairs touched. All five pale pieces got better within seven weeks. The other five did not touch and died. Algae started moving between touching pieces within three days.
The pieces must be exact copies of each other to join together. So this method is not ready to help whole reefs, or large groups of corals. It helps damaged corals get better, but cannot stop seas getting hotter.
