Coral reefs are the most biologically diverse marine habitats in the world. As well as providing vital protection against storm damage and coastal erosion, millions of people rely on reefs for food.

Yet years of unsustainable fishing practices, pollution and rising sea temperatures means that up to one-fifth of all coral reefs around the world have already been destroyed. So the battle is on to safeguard their future.

Dr Mary Hagedorn of the Smithsonian Conservation Biology Institute has been on a global mission to create a seed bank to protect the world's highly-threatened coral biodiversity. Using technology and techniques similar to those used in human sperm banks, Hagedorn and her colleagues were the first on the planet to cryogenically freeze the sperm and stem cells of coral.

Russell Beard travels to Oahu, Hawaii, to join Dr Hagedorn's team on a spawn gathering trip to gather and freeze endangered coral sperm and cells for future use. 

Source: Al Jazeera