The king scallop (Pecten maximus) is one of two species of scallop cultivated in the UK, the other being the queen scallop (Aequipecten opercularis).
King scallops live on the seabed, preferring substrates of clean firm sand, fine gravel or sandy gravel. They recess into the sediment to a level with the upper shell; sometimes they are partially covered. Selecting a site that is suitable for king scallop cultivation is clearly of fundamental importance. It requires careful consideration of a range of different factors.
Scallop seed are initially raised in suspended cultivation, in pearl and lantern nets suspended from long-lines.
Pearl nets are generally used for small (10-30 mm shell height) scallops and lantern nets for larger animals. At first the pearl nets can be stocked at 50-80 scallops per net, reducing to 20-30 as they grow. From 30-60 scallops can be put into each compartment of a lantern net initially (at 30-40 mm) but this should be reduced to no more than 10- 15 per compartment at 60-80 mm.
Some companies have developed plastic mesh cages that can be stocked with bivalve molluscs, including scallops, and suspended in stacks from long-lines. However, it is very costly to use these suspended cultivation methods to raise scallops to market size. This is mainly due to the cost of the large number of nets or cages needed, to avoid crowding, which can lead to mortality, and maintenance and labour charges over a long grow-out period, usually about 4 years. Growth rates of scallops in suspended cultivation, provided that they have plenty of space to themselves, are similar to those for animals on the seabed.
However, studies have shown that wave action, and thus movement in the nets, can be a stress factor as the scallops grow. There can also be problems with fouling of the nets and bio-fouling of the shells with suspended cultivation methods. Shell bio-fouling is a major drawback of the ear-hanging cultivation technique, and can result in mortality.