Queen scallop (Aquipecten opercularis)

Fishery

Queen scallops are now predominately fished around the Isle of Man in the summer months, when they are active swimmers, using otter trawls. A small and limited fishery does still occur with toothless dredges typically in October in a small area in the south of the Island (5 licenced vessels and 58 t TAC in 2020). In 2020 there were around 43 licenced trawl vessels with a Total Allowable Catch of 647 t for the general territorial sea (~£425,000 first sale value) (source: DEFA Electronic Daily Catch Returns and EU Logbooks). The minimum landing size for king scallops in Isle of Man territorial waters is 55 mm.

Life Cycle

The queen scallop is a medium-sized scallop with two convex shells of variable colour. It is often light-pink to brown, orange or yellow, and may be overgrown with encrusting sponge. This species can grow to 9 cm in diameter. The lifespan of the queen scallop can be from 6-10 years and they reach sexual maturity at 1 year. Queen scallops have both male and female reproductive organs (hermaphrodites) and fertilization takes place externally. Their larvae develop in the water column and are dispersed in the currents. After ~11-30 days the larvae settle from the water column and attach to suitable substrates by their byssal threads (strong, silky fibers). Young scallops remain attached by byssal threads for a period of time and then settle on the seabed. Queen scallops are known to be quite mobile and swim readily in response to disturbances such as predators, divers, and fishing gear. They swim by rapidly opening and closing their shells which allows the scallop to rise off the seabed at a steep angle before swimming horizontally for a short distance and sinking back to the seabed.

Habitat & Distribution

Queen scallops are usually found from the shallow sub-tidal up to depths of 100 m. They are often found in high densities on sand and gravel substrates and lie on top of the seabed instead of becoming settled in the sediment like the king scallop. They have also been found amongst horse mussel beds. This species is found from South of Norway to the Mediterranean and the Canary Isles. Queen scallops are filter feeders and eat micro-organisms in the water column.