The survey reports that the shellfish species cultivated in
Scottish waters in 2020 were:
Production was dominated by mussel and Pacific oyster, although small quantities of scallop, queen scallop (queen) and native oyster were also produced. The 2020 production data for each species by region are given in Table 1.
|Region||Mussel||Pacific oyster||Native oyster||Queen||Scallop|
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.
 A proposed name change to Magallana gigas remains controversial (Bayne et al. 2007, Journal of Shellfish Research. 36, 545-547)
Table production by species is illustrated in Figure 1 (see page 4), while trends in production for the table market and on-growing in Scotland are presented in Table 2.
|For the table||2011||2012||2013||2014||2015||2016||2017||2018||2019||2020||% change 19-20|
|Pacific oyster (000s)||3,136||2,706||1,891||3,392||2,693||3,534||5,034||4,031||4,393||2,938||-33|
|Native oyster (000s)||350||317||260||242||200||201||200||142||103||75||-27|
|For on-growing||2011||2012||2013||2014||2015||2016||2017||2018||2019||2020||% change 19-20|
|Pacific oyster (000s)||1,400||3,190||6,216||6,792||5,864||4,584||3,849||4,240||2,405||1,663||-31|
|Native oyster (000s)||1||677||1,015||749||13||323||481||344||327||10||-97|
Mussel production, for the table, decreased by 15% in 2020 (see figure 1) to 5,661 tonnes. The greatest regional contribution to mussel production was from Shetland, accounting for 4,427 tonnes or 78% of Scotland’s total. Pacific oyster production decreased by 33% from 2019. Highland region produced 56% of Scotland’s total farmed Pacific oysters in 2020. There was a very small amount of queen scallop production during 2020 as the main producer reported no production during 2020 due to the COVID-19 pandemic lockdown. The production of farmed scallops and native oysters both decreased by 27%. 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. During 2020, the biggest impact on shellfish production was the COVID-19 pandemic with a loss of much of the table trade to the hospitality sector during periods of lockdown and travel restrictions.
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 £0.33 per shell; native oyster, £0.60 per shell; scallop, £2.32 per shell; queen scallop, £0.13 per shell and mussel £892 per tonne. The value of the table trade is estimated from the production figures shown in Table 1 (see page 2).
Mussel: £5.0 million
Pacific oyster: £0.97 million
Native oyster: £0.05 million
Scallop: £0.04 million
Queen: > £0.0001 million
In 2020, the total value at first sale for all species was calculated at approximately £6.1 million, a decrease of 23% from the £7.9 million estimated in 2019. This decline is largely due to impacts from the COVID-19 pandemic with many businesses reporting lost trade while the hospitality sector was in lockdown during much of 2020.