Kelp forests around Britain are as large as broadleaved forested areas on land, and they are some of the most productive ecosystems on the planet. They support a huge variety of other seaweeds and animals, and serve as nurseries for fish species including Atlantic cod and pollock. Kelp also protects the Scottish coastline from erosion. An Ayr-based company called Marine Biopolymers (MBL) is now seeking a licence from Marine Scotland to take kelp from the Scottish seabed using a large mechanical arm. MBL commercially extracts polymers from seaweed for use in industries including food and pharmaceuticals. Their dredging method would harvest seaweed using a mechanical comb, making it a new industry in Scottish waters. Prof Juliet Brodie, a merit researcher at the Museum, has been studying the seaweeds of Britain for decades, and has recently turned her attention to analysing Scottish kelps. She says she was 'heartbroken' when she heard that the application had been made. She says, 'Kelp forests are unique and precious. Mechanical removal of kelp from the seabed will destroy this unique habitat. There will be no nurseries for fish, no protection of our coasts and the world will be a poorer place. We need to wake up to the destruction of these ecosystems before it is too late.'

Disturbing the sea bed MBL claims that over five years it will start harvesting 30,000 tonnes per year of the seaweed Laminaria hyperborea, a large, leathery brown kelp. The company propose to use a comb-like harvester measuring between three and four metres to trawl the seabed. This method removes entire kelp plants, with the idea that juvenile plants are left to promote more rapid recovery - although the evidence for this in Scottish waters is limited. In a report, MBL said, 'Although at-sea harvesting of L. hyperborea would be a new industry in Scotland, such harvesting has been carried out sustainably for many decades in Norway, France and Iceland.' However, researchers in Norway have investigated the effects of kelp dredging on commercially important species, and found 90% fewer young fish in harvested areas. Existing Scottish kelp harvesting is limited to hand-cutting fronds, and ensuring that the stems and holdfasts (the part of the plant that connects to the seabed) are left intact. The new proposed dredging method will rip up entire kelp plants, including their holdfasts. Scottish Natural Heritage suggests that Scottish kelp holdfasts typically house between 30 and 70 different species, including worms, molluscs and anemones. In turn, these animals provide food for fish and mammals like seals and otters. Juliet says, 'We know from our work at the Museum that this species is also threatened by climate change in the south of Britain. These Scottish populations of kelp are doing well at the moment, which could be an indication that they are resistant to the effects of warmer waters, making them even more vital to protect.' Juliet also says that kelp dredging will also lead to a reduction of genetic diversity making kelp forests more susceptible to potential diseases and climate change. The Sustainable Inshore Fisheries Trust has expressed concerns that the introduction of dredging could damage Scotland's reputation for high-quality, sustainable marine products. It could also drive down prices, possibly threatening the livelihoods of those who hand-harvest seaweed in the area.