Scottish shellfish farm production survey 2016

Health Influences on the Industry

In accordance with Council Directive 2006/88/ EC, a risk based surveillance programme targeting 131 shellfish site inspections was undertaken during 2016. On these visits, facilities, stock health, bio-security measures plans, movement records and details required for authorisation were checked. Movement restrictions placed due to confirmation of the presence of Bonamia ostrea, remained in force in Loch Sunart and in West Loch Tarbert, Argyll during 2016. These movement restrictions covering both sea lochs prevent the relaying of native oyster from them ( see Appendix 3 for maps of areas under movement restrictions). Approved zone status for bonamiasis, marteiliasis and Ostreid Herpes Virus-1 Microvariant ( OsHV-1 µvar) continued to protect the health of both wild and farmed susceptible shellfish stocks for the remainder of Scotland's waters.

Most of the reported mortalities during 2016 were attributed to: predation from wild ducks, starfish, crabs and oyster catchers; fouling by sea squirts; adverse weather conditions including storms and temperature extremes; damage due to grading and handling and from natural causes. Reports of high, unexplained shellfish mortalities generated two shellfish diagnostic cases during 2016, at sites holding Pacific and native oysters. Results of diagnostic investigations showed no association with listed (notifiable) diseases. It is the responsibility of shellfish farmers to inform Marine Scotland of any abnormal or unexplained shellfish mortality on their sites ( see guidance on shellfish mortality in appendix 1).

In 2016, there was a continued demand for imported mussel seed into Scotland to supplement the vagaries in natural settlement. The industry should be aware of the increased disease risk with the introduction, movement and deposit of stock on site and the importance of ensuring good bio-security practices when sourcing shellfish from other areas.

Following completion of a targeted surveillance programme, the UK has been granted disease free status for OsHV-1 μvar (Decision 2014/12/ EU). This includes the territory of Great Britain except the River Roach, River Crouch, Blackwater Estuary and River Colne in Essex, the north Kent Coast, Poole Harbour in Dorset and the River Teign in Devon. In addition, Guernsey and the territory of Northern Ireland (except Dundrum Bay, Killough Bay, Lough Foyle, Carlingford Lough and Strangford Lough) have also been granted disease free status for OsHV-1 μvar.

The whole of the UK is recognised as free from infection with Marteilia refringens.

The whole coastline of Great Britain is recognised as free from infection with Bonamia ostreae except for the following areas; the south coast of Cornwall from Lizard to Start Point; the coast of Dorset, Hampshire and Sussex from Portland Bill to Selsey Bill; the area along the coast of North Kent and Essex from North Foreland to Felixstowe; the area along the coast in south-west Wales from Wooltack Point to St Govan's Head, including Milford Haven and the tidal waters of the East and West Cleddau river; Loch Sunart and West Loch Tarbert, Argyll. The whole coastline of Northern Ireland is recognised as free apart from Lough Foyle and Strangford Lough. Guernsey, Jersey, Herm and the Isle of Man are all recognised as Bonamia ostreae free areas.

In 2015 six compartments in Ireland were also recognised as free from OsHV-1 μvar: compartment 1 - Sheephaven Bay, compartment 3 - Killala, Broadhaven and Blacksod Bays, compartment 4 - Streamstown Bay, compartment 5 - Bertraghboy and Galway Bays, compartment 6 - Poulnasharry Bay and compartment A - Tralee Bay Hatchery.

Movements of Pacific oysters into an area recognised as free from OsHV-1 μvar must originate from another disease free area. Movements are still allowed from disease free areas to non-approved areas.

http://www.gov.scot/Topics/marine/Fish-Shellfish/aquaculture/diseases/notifiableDisease/oshvdec