Scottish mussel and Pacific oyster production grew by 5% last year

Scotland’s shellfish farmers produced a record volume of common mussels (Mytilus spp.) for the table last year, up by 5% from 11,690 tonnes in 2024 to 12,303 tonnes, statistics published by the Scottish Government today show.

Shetland produced 10,461 tonnes (85%) of Scotland’s mussels, followed by Highland (1,082 tonnes), Strathclyde (506 tonnes), and Western Isles (254 tonnes).

During 2025, more than 2.5 million Pacific oyster shells (Magallana gigas) were produced for the table market, also a 5% increase from the 2024 total. This is the equivalent of 203 tonnes, assuming an average weight of 80g per oyster.

More than half of Scotland’s Pacific oysters were grown in Strathclyde, which produced 1,548,000 shells. It was followed by Western Isles (529,000 shells), Highland (257,000 shells), and Orkney (200,000 shells). Shetland produced 4,000 shells.

Higher returns, fewer jobs

The first-sale value of the Scottish shellfish farming sector was estimated at £15.1 million, representing an 8% increase if compared with 2024. By species, the first-sale value was:

• Pacific oyster: £1.5m
• Native oyster: £0.1m
• King scallop: £0.07m
• Common mussel: £13.4m

However, employment in the sector decreased by 6% compared with the previous year, with 227 full-time, part-time and casual staff employed during 2025.

The figures are included in the Scottish Government’s Scottish Shellfish Farm Production Survey 2025, which is based on data collected directly from authorised shellfish farming businesses.

The survey also revealed that native oyster production decreased by 7% from 170,000 shells to 158,000 shells in 2025.

King scallop production increased by 4%, from 23,000 shells to 24,000 shells in 2025, all in Highland. Production of queen scallops is not reported due to low levels of production and a small number of producers.

Spat settlement

The number of common mussel production sites with sufficient spat settlement increased by 15% from 97 sites to 112 sites in 2025.

For shellfish health purposes, 110 out of 272 sites were inspected during 2025 under a risk-based surveillance programme. Movement restrictions remain in place for the presence of Bonamia ostreae at Loch Sunart and the Dornoch Firth in Highland region, West Loch Tarbert and Lynn of Lorne, Loch Creran and Loch Etive in Strathclyde region.

Great Britain maintained disease free status with regard to Bonamia ostreae, Marteilia refringens and ostreid herpesvirus-1 microvariant (OsHV-1 µvar), with the exception of specific compartments under movement restrictions.