Production at the Ardtoe hatchery is targeted mainly at servicing the needs of existing
customers and is constrained by their ability to produce sufficient levels of live microalgae at
that latitude. This means that there is a greater reliance on intensive hatchery production of
phytoplankton. Therefore Ardtoe prefer to sell seed oysters at the relatively small size of 2 to
4mm although they can sometimes produce limited numbers of 6 to 8mm seed (Tim Atack,
Viking Sea Farms Ltd., pers. comm.). Small seed of 2 to 4mm would most likely require
some form of intermediate on-growing stage either inter-tidally or through the use of Floating
Upweller Systems (FLUPSY), as is currently undertaken by one grower in the South West of
England (see also Section 2.2.3). This could therefore offer a new market opportunity for
existing oyster growers if there becomes a high demand for native oyster seed for offshore
culture.