Scottish Shellfish Farm Production Survey 2019

Production

The survey reports that the shellfish species cultivated in Scottish waters in 2019 were:

Mussel: Mytilus spp.
Pacific oyster: Crassostrea gigas^[1]
Native oyster: Ostrea edulis
Queen scallop: Aequipecten opercularis
Scallop: Pecten maximus

Production was dominated by mussel and Pacific oyster, although small quantities of scallop, queen scallop (queen) and native oyster were also produced. The 2019 production data for each species by region are given in Table 1. Additionally in 2019, there was cultivation of common periwinkle (Littorina littorea) however, due to the small number of these being produced it is not possible to summarise these without revealing commercially sensitive information.

NB: This report lists regions with active shellfish farms operated by authorised aquaculture production businesses.

Conversion to weight used the following assumptions (based on industry figures): individual oysters averaged 80g; individual scallops averaged 120g; individual queens averaged 40g.

Table = sales directly for human consumption;

On-growing = sales to other businesses for on-growing.

Table production by species is illustrated in Figure 1, while trends in production for the table market and on-growing in Scotland are presented in Table 2.

Mussel production, for the table, decreased by 3% in 2019 (see figure 1) to 6,699 tonnes. The greatest contribution in regional mussel production was from Shetland, accounting for 5,324 tonnes or 79% of Scotland's total. Pacific oyster production increased by 14% from 2018. The Strathclyde region produced 53% of Scotland's farmed Pacific oysters. The queen scallop production figure has not been updated from 2018 as data could not be collected during the COVID-19 pandemic lockdown. The production of farmed scallops decreased by 16%. Both these sectors continuing to target small niche markets. Production of native oysters decreased by 27% from 2018. Native oyster production accounts for a small percentage of total oyster production, however, demand for this species continues to be high. Historical data for all shellfish species show that production levels vary year on year. This can be due to a number of different factors such as poor spat fall, algal toxins, poor growth, adverse weather and fluctuations in market prices. However, production was not affected by COVID-19 restrictions, as the survey covers the period prior to the pandemic.

Prices of farmed shellfish fluctuated throughout the year. Their value at first sale was estimated from the following figures obtained from the shellfish farming industry. These vary with demand, level of production and geographical area of origin. The average price of Pacific oyster was £0.34 per shell; native oyster, £0.60 per shell; scallop, £1.84 per shell; queen scallop, £0.13 per shell and mussel £920 per tonne. The value of the table trade is estimated from the production figures shown in Table 1.

Mussel: £6.2 million
Native oyster: £0.06 million
Queen: £0.002 million
Pacific oyster: £1.6 million
Scallop: £0.05 million

In 2019, the total value at first sale for all species was calculated at approximately £7.9 million, a decrease of 17% from the £9.5 million estimated in 2018. This decline is largely due to a decrease in the average price estimate of mussels in 2019, see Appendix 2 for more details.