Spot The Seaweed Invader

APPEAL LAUNCHED TO TRACK SPREAD OF INVASIVE SEAWEED

Scottish Natural Heritage (SNH) has launched a public appeal to help track the spread of a non-native species of seaweed that has been spreading rapidly along Scotland's west coast.

SNH is asking members of the public to report any sightings of wireweed, which is also known as japweed or Sargassum. The species is native to the western Pacific but has found its way to these shores. It was first recorded in the UK in 1973 on the Isle of Wight, and has since spread along the south coast of England and into Wales and Ireland.

The first reports of the species in Scotland were in Loch Ryan in 2004. Since then it has been found at Great Cumbrae Island and on the North Ayrshire coast, Loch Fyne and the Firth of Clyde. This year there have been new reports of it in the Firth of Lorn.

Although harmless in its native western Pacific, wireweed is a nuisance species in the UK. It grows very rapidly in the summer and where it becomes established on the lower shore it can reduce the diversity of native seaweeds by outgrowing and shading them. It can foul boat hulls, propellers and water intakes, and it can cause problems for shellfish farming equipment.

The species is included in the five-year Species Action Framework, developed by SNH, which prioritises management action to protect and enhance Scotland's biodiversity.

Fiona Manson, marine advisory officer at SNH said: "The spread of wireweed in Scotland is cause for concern." She added: "The presence of wireweed in Scotland is a stark reminder that we must do everything we can to prevent non-natives from getting here in the first place. It poses a threat to our native marine wildlife, as well as to boats and fish farming. The species is very difficult to control once it has established and can spread rapidly because broken-off fragments float and remain reproductively active for some weeks.

"It is significant that the species has been found in the Firth of Lorn, as this confirms it is spreading outside the Firth of Clyde. We are very keen to find out where wireweed is in Scotland. Knowing where it is now will be the first part of helping us decide how to deal with it. As part of a major survey of the species we are therefore asking members of the public working at, or visiting, the coast to keep a look out and report any wireweed they find."

Anyone who has spotted the species is asked to report the sighting, with an exact location or grid reference if possible, by emailing wireweed@snh.gov.uk or by calling Fiona Manson on 01738 458641.

Information about wireweed, and what to look for, can be found at www.snh.org.uk/wireweed.

Leaflets to help identify the species are available from Fiona Manson at SNH or from Dr Elizabeth Cook at the Scottish Association for Marine Science Laboratory in Dunstaffnage.

Thanks Bill for posting this. I will have a look along Sandside when I get the chance. However, it puzzles me why Scottish Natural Heritage needs to know anymore about this problem when they already know there is a problem and they expect more of the problem. It seems to be nugatory exercise when the causes of the introduction are probably well known, (climate change and illegal ballast tank blowing) and that there is no remedial action plan. And if there was a plan, then it would be totally futile. It all seems too little too late.

By looking at the locations listed, I'd suggest that this is spreading the same way the Caulerpa taxifolia outbreak spread in the Med - on the anchors of sailing yachts.

More info on Sargassum here

L

Will certainly keep a look out whenever i go down to the local beaches for any sightings Bill, thanks for the information.

Regards,
Andy