Sir David Attenborough has insisted it is “absolutely imperative” that action is taken to preserve kelp forests in Scotland’s waters.

The broadcaster made what is thought to be his first intervention into politics north of the border to call on MSPs to preserve the marine habitats, as they prepare to vote on new legislation which could ban dredging for kelp in Scottish waters.

Mark Ruskell, the Green MSP, successfully amended the Scottish Crown Estate Bill to ban the removal of entire kelp plants, allowing harvesting only where the plant could recover.

The move was prompted by an application for dredging seaweed on an industrial scale. The Ayr-based firm Marine Biopolymers reportedly wanted to harvest 30,000 tonnes of kelp each year off the west coast using