Lotion in the ocean: is your sunscreen killing the sea?

Up to 14,000 tonnes ends up in coral reef areas each year, but scientists are divided on how we can best protect our skin without harming the environment

Related: Deadly coral disease sweeping Caribbean linked to water from ships

Autumn Blum was 5 metres underwater, scuba diving off the Pacific island of Palau, when she looked up towards the surface and saw a rainbow.