Luke Marshall is a second generation shellfish farmer. From their base at Porthilly farm near Rock the Marshall family have been farming shellfish in the Camel estuary for over twenty years. Luke has followed his father Tims footsteps and now works full time for the family business, Rock shellfish, producers of the famous Porthilly Oysters and cultured mussels. Both products are recommended by Cornwall Good Seafood Guide as sustainable. Pacific oysters are bought in as tiny juveniles and on grown in cages held on frames on the seabed in the estuary. They feed on natural plankton and grow well in the clean waters of the estuary. Mussels are also bought in as juveniles and laid on mussel beds in the estuary. They grow by feeding on natural plankton and when they are large enough they are harvested using a mechanised lift dredge. All the shellfish are sorted and purified in UV sterilized recirculating seawater tanks before being sent out to their many customers.