C14 – West of Scotland
Shellfish farming in Scotland
The shellfish farming sector is an important contributor to national and rural economies in Scotland. The Scottish Government has set an ambitious target to double shellfish production to 13000 tonnes by 2020, however this must be achieved sustainably. Mussel (Mytilus sp. and Pacific oysters (Crassostrea gigas) are the main species produced in terms of value and tonnage. Although native oyster (Ostrea edulis) production is a small percentage of total oyster production, demand for the species is high. Other farmed species include scallop (Pecten maximus) and Queen scallop (Aequipecten opercularis). Most farms are located in sheltered bays and lochs (fjords) throughout the west coast and highlands and islands. Mussels are usually grown on suspended ropes, also known as longlines, whereas oysters are normally farmed using net bags supported by trestles that are fixed just above the sea bed.
Effects of climate changes
Mussel and oyster culture in Scotland may be affected by climate change. It is likely that an increase in temperature will affect recruitment, feed availability and growth. Furthermore, warmer waters may enhance the invasiveness of non-native species. Mytilus trossulus is a non-native species that has been found in Scottish waters, because M. trossulus has a higher temperature range it could spread further due to rising temperatures. This could have economic consequences as M. trossulus has a lower meat yield and thinner shell which results in a lower market value than the native Mytilus edulis so it is commercially damaging to the Scottish mussel sector. There may be other threats to production and also food safety concerns due to water quality issues, disease and harmful algal blooms. Growth and production may also be affected by changes in pH which could have physiological effects.
Using data collected at a farm on the west coast of Scotland, ClimeFish researchers will develop, adapt and use biological forecasting models to predict growth and production of mussels, pacific oyster and native oyster until 2050.