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Wireweed - update

The following are brief summaries of some of the action that we and our partners have done since the Species Action Framework was launched. They're in chronological order, with the most recent updates at the top of the page.

27 October 2009

Marine Non-Native Species: Responding to the Threat - On 27th October 2009, a Sharing Good Practice event was held at Battleby, near Perth, entitled "Marine Non-Native Species: Responding to the Threat". This brought together a wide range of marine stakeholders to discuss the risks posed by marine non-natives and the most effective ways of responding to these threats. The event report and presentations are available here.

Wireweed Review - In 2009, Scottish Natural Heritage published "Sargassum muticum in Scotland, 2008: A review of information, issues and implications " by Dee Davison.

26 February 2009

A meeting of the Sargassum (Wireweed) steering group was held on 26th February 2009 at Heriot-Watt University, Riccarton. The results from two projects carried out in 2008 were presented (see links below). Future work to build on these studies was discussed. The minutes of the meeting can be accessed below.

Papers produced by the Sargassum Steering Group

31 July 2008

In early July, the first in a series of surveys was carried out to look for the non-native seaweed, Sargassum muticum (wireweed) in the Firth of Clyde.

Initially, a predictive model was used to pinpoint areas where wireweed is most likely to become established. The model was based on known source populations, environmental factors that disperse the seaweed (wind and currents), and suitable conditions for growth (substrate type, depth, exposure to waves etc). Surveys were then carried out at these sites to search for the seaweed.

A survey team from Scottish Natural Heritage and Royal Haskoning visited a number of sites around the Clyde, including Largs, Hunterston, Cumbrae, Arran, the Kintyre peninsula and Loch Fyne. Wireweed was found growing almost everywhere that we looked, confirming that it is now widespread within the Firth of Clyde. In some areas, wireweed is well-established, forming dense stands of plants; in others, individual plants or drifting fragments were found.

A second survey will take place in early August, focusing on the Firth of Lorn and Oban areas. We hope to find out whether Sargassum has already spread beyond the Clyde and into western coast waters. Drifting fronds have previously been found as far north as Oban but it is not known if plants are established in these areas yet.

11 October 2007

Scottish Natural Heritage has recently let a 2-year research contract to Royal Haskoning to investigate the distribution of wireweed in Scottish waters. The work will involve predictive mapping to identify areas where establishment of wireweed is most likely on the west coast of Scotland, based on known habitat preferences, prevailing currents and source populations. This work will highlight any areas of high conservation value that are at risk. In addition, the project will investigate the impacts of wireweed on native biodiversity and review possible removal methods in areas of high conservation value.

Scottish Natural Heritage has initiated an awareness-raising campaign, in collaboration with the Scottish Association of Marine Sciences and SEPA, to inform the public about the spread of wireweed and to encourage them to report sightings of this species. A waterproof leaflet has been produced which describes wireweed, where it is likely to be found, and what to do if it is found. This leaflet will be distributed to marine users, both commercial and recreational, and copies can be ordered from Scottish Natural Heritage's publications unit (pubs@snh.gov.uk ).  A web page and e-mail address has been set up to report wireweed sightings.

A press release will be made in the near future to publicise the awareness-raising campaign.

Scottish Natural Heritage press releases:

25 September 2008 Invasive seaweed spreading fast  - An alien species of seaweed, which can cause commercial and environmental damage, has been found as far north as Loch Sunart in Ardnamurchan and Tarskavaig on Skye, and as far south as Luce Bay in the Solway Firth. The sightings, reported by members of the public, mean that wireweed (Sargassum muticum) has spread much further and much more quickly than previously thought. Scottish Natural Heritage (SNH) has asked the public to continue reporting any sightings to help track its spread.

30 June 2008 SNH asks boat owners to check for aliens  - A non-native species of seaweed, known as wireweed, has been spreading along Scotland's west coast and Scottish Natural Heritage (SNH) is investigating just how widespread it has become. The species is included in SNH's Species Action Framework which promotes action to protect and enhance Scotland's biodiversity.

24 October 2007 Appeal launched to track spread of invasive seaweed  - Scottish Natural Heritage (SNH) has today (24 October 2007) 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.