How bad could the tanker collision be for the environment?

Environmental organisations and the UK authorities are assessing how damaging the collision of an oil tanker and a cargo ship in the North Sea will be for marine species and nearby wildlife populations.

It's still too early to tell whether it will have a major impact, and weather conditions in coming days will be a major factor.

But a lot will depend on exactly which toxic chemicals have been spilled and how much of them.