Invader moves into Loch Fyne – Fishupdate.com

Invader moves into Loch Fyne Published:  29 August, 2006

Wireweed (Sargassum muticum) Photo courtesy of SNH

A NON-NATIVE (alien) seaweed has been discovered in Loch Fyne (Argyllshire) for the first time, Scottish Natural Heritage (SNH) revealed today.

Japweed or Wireweed (Sargassum muticum) was spotted by a Seasearch co-ordinator for the Marine Conservation Society in west Scotland.

It is the fourth time that the alien species has been found in Scotland since it was first recorded two years ago.

Sargassum is a nuisance species as it grows very rapidly in the summer and when it becomes established on the lower shore it can reduce the diversity of native seaweeds by outgrowing and shading them. It also has the potential for an economic impact through, for example, the fouling of boat hulls, clogging water

intakes and on shellfish farming equipment.

Fiona Manson, Maritime Advisory Officer at SNH said:

“Sargassum is a native of the western Pacific and is unwelcome because of theimpact it can have on our native marine wildlife. It is not as problematic as some non-native species, which can cause millions of pounds of damage, but Sargassum is colonising the Clyde at an alarming rate and there is very little we can do to control it. It is a stark reminder that we must do everything we can to prevent non-natives from getting into Scotland in the first place.”

Sargassum 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 Sargassum in Scotland were in Loch Ryan in 2004 and, since then, populations have also been found at Great Cumbrae Island and on the North Ayrshire coast. In July 2006, Sargassum was reported in Loch Fyne, and it may already be present, but as yet unidentified, in other locations in the Firth of Clyde.

Sargassum is very difficult to control and can spread rapidly because

broken-off fragments float and remain reproductively active for some weeks.

Indeed it may already be too late to prevent further spread up the West Ccoast.

SNH would like to know more about how far Sargassum has reached this year, and is appealing to members of the public to help by letting them know if you have spotted it during the summer.

If you think you have seen this seaweed you could help by reporting it to SNH by calling Fiona Manson on Tel: 01738 458641 or email enquiries@snh.gov.uk

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