To report the finding of slipper limpet and measures underway to remove the infestation.

1.1 It was reported to the Chief Executive in writing on 27 February 2007 by Myti Mussels Ltd that approximately 20 slipper limpets had been found in a sample of 4 tons of mussel from Lay 2 of the Menai Strait (East) Fishery Order. Nearly all the limpets were juveniles, about 10mm in length but one pair were slightly larger, (15 and 25mm) and showed evidence of commencing reproductive activity.

1.2 On the present evidence, it appears most likely that the limpets were introduced to the Strait in a consignment of seed mussel brought from the English Channel in summer 2006.

2.1 The infection found appears small and limited in area. However, the slipper limpet is a highly invasive species in areas of Europe, Southern England and Wales where it has become established. It attaches to other molluscs such as oysters and mussels from where it may reproduce rapidly to eliminate other species. If allowed to establish it could significantly alter the local biodiversity causing permanent damage to nature conservation interests and economic damage to shellfish culture operations and other shell fisheries.

2.2 Any introduction of this alien species is a matter of great concern to the Committee, CCW and the shellfish industry. All parties agree that everything possible must be done to remove any evidence of infestation and establish systems and procedures to prevent further reintroductions.

2.3 However, we may also note that previous accidental introductions of slipper limpets to the North Wales and Liverpool bay areas have died out without establishing permanent populations. This indicates that slipper limpets may not persist and thrive in the Menai Strait.

3.1 Myti Mussels Ltd has taken urgent action to remove the entire consignment of mussels containing slipper limpet. The operation commenced on March 5. Approximately 1000 tons of mussel seed are being dredged from lay 2 and transported by road to Dutch shellfish beds where slipper limpets are already endemic.

3.2 PFO Martyn Boyce visited Myti Mussels on 7 March to observe the operation in progress and obtain the co-ordinates of the area to be cleared. Further observations by Committee Officers will continue until the operation is completed. Committee Senior Scientist Bill Cook has planned a site visit on the very low tide of 22 March by which time much of the infected area should have been cleared. Bill will survey the area for any further slipper limpet presence. CCW have been invited to attend.

3.3 Further wider survey of the Strait may be appropriate once the infected stock has been removed. Requirements will be discussed and agreed with CCW.

3.4 The mussel industries’ biosecurity procedures which are designed to ensure alien species are not introduced through the transhipment of mussel seed will be reviewed and tightened. The aim will be to determine how this infestation occurred and ensure robust procedures are in place prevent any future introductions.