The Scottish Parliament is expected to ban mechanical harvesting of kelp during a vote later.

The proposal is part of the Scottish Crown Estate Bill, which is likely to become law following a final debate at Holyrood on Wednesday afternoon.

Environment Secretary Roseanna Cunningham announced on Tuesday the Scottish Government would back a prohibition of kelp dredging.

The ban was first proposed by the Scottish Greens after more than 10,000 people signed a petition calling for the practice to be outlawed.

The Environment, Climate Change and Land Reform Committee voted in favour of an amendment to the Bill from the party’s environment spokesman Mark Ruskell last month.

Ms Cunningham told MSPs: “We recognise that kelp is an important part of our marine biodiversity and, having considered amendments to the Crown Estate Bill, we intend to support Mark Ruskell’s amendment, although there are some clarifications and qualifications that require to be made.

“It is our view that commercial use should not extend to power stations or commercial ports or other, similar public infrastructure being prevented from removing kelp species for maintenance or for other public interest reasons and nor should it prevent appropriate research and development.

“Removals shouldn’t be prevented where the activity is hand-cutting, which SNH have advised is sustainable, and I can say that I will consider the need for guidance or directions to managers on these issues.”

She said she would be announcing a review of the regulations underpinning kelp harvesting, including farming of the seaweed.

Mr Ruskell said kelp forests are “hugely important” to Scotland’s marine environment and he is delighted to have secured the government’s backing.

He said: “They dampen waves, protecting coastal communities from flooding and erosion, act as a habitat for hundreds of species, and store more carbon dioxide than the rainforest.”

Industry bosses earlier this week warned legislation banning the practice in Scotland’s waters could hit the economy by as much as £300 million.

Tom Shields, chairman of industry body Chemical Sciences Scotland, said the country risked no longer being seen as a competitive place for science-based businesses.