Pictured: fresh mussels from the Isle of Mull, Scotland.
Photo: Richard Kellett / Adobe Stock.
Scotland's shellfish farming sector enjoyed a boost in economic value as well as achieving record-breaking production levels in 2023, according to the latest Scottish Shellfish Farm Production Survey.
The annual survey, conducted by the Scottish Government's Marine Directorate, provides detailed statistics on employment, production, and economic value of the sector.
The survey showed that the economic value of the Scottish shellfish sector increased substantially from the previous year, with an estimated value at first sale rising by 36% from 2022, reaching approximately £14.1 million.
The survey also revealed a landmark production year for Scotland's mussel farmers, with a historic 10,311 tonnes of common mussels were harvested for the table market, the highest ever recorded in Scotland, representing a 13% increase from 2022.
The survey showed that Scotland's mussel production is dominated by 12 businesses, each producing over 200 tonnes of common mussels, contributing 92% of Scotland’s total mussel output in 2023, with Shetland the principal location for mussel farming.
In 2023, the production of Pacific oysters reached 3.9 million shells, a 4% decrease from the previous year. Despite the decline, Pacific oysters remain a key species alongside common mussels, the report said. Four businesses accounted for 69% of the Pacific oyster production, with the majority of sites located in Strathclyde, on Scotland's west coast.
King scallop production also declined in 2023, dropping from 39,000 to 24,000 shells, while native oyster production saw a slight rise from 109,000 to 111,000 shells. However, Queen scallop production data was not reported due to low levels.
The survey highlighted the industry's consolidation, with the total number of authorized shellfish farming businesses declining from 144 in 2014 to 103 in 2023.
Despite this, the number of sites producing shellfish for sale increased slightly from 167 in 2022 to 169 in 2023, with 59% of these located in Shetland, Scotland's main mussel-producing region.
Employment in the sector decreased by 4% to 246 workers, composed of 114 full-time and 132 part-time and casual workers. While the number of full-time and casual staff decreased, part-time and casual female staff numbers increased during 2023.
The report also pointed out that many businesses cultivate multiple species at the same sites, such as Pacific and native oysters or mussels and Pacific oysters, due to similar cultivation techniques.
Out of 294 sites, 133 were inspected for shellfish health under a risk-based surveillance program. Movement restrictions due to the protozoan oyster parasite Bonamia ostreae remain in specific regions, but Great Britain as a whoel maintained disease-free status for bonamiasis (another oyster parasite), marteiliasis (which can affect both mussels and oysters), and OsHV-1 µvar (a virus which particularly affects Pacific oysters).
The report noted a continued demand for Pacific oyster spat in Scotland during 2023, and warned: "The shellfish farming sector should be aware of the increased disease risk with the introduction, movement and deposit of stock on site and the importance of ensuring good biosecurity practices when sourcing shellfish from other areas."