DORSET CLEANER FISH
The salmon farming industry has been suffering infestations of sea lice (Lepeophtheirus salmonis and Caligus elongatus) since the industry started in the late 1970's. This has traditionally been treated with pesticides administered either as an oral treatment or as a bath. In recent years the lice have become resistant to the pesticides used and the industry has turned to other means of controlling lice populations. One of these methods uses fish such as wrasse and lumpfish which naturally clean external parasites on fish (cleaner fish) in the wild. These methods provide the ideal biological control of lice populations and do not impact on the environment or reduce the growth of salmon.
The best 2 species used are ballan wrasse (Labrus bergylta) and lumpfish (Cyclopterus lumpus). Although there are hatcheries for both these species in the UK, ballan wrasse production has proved difficult whereas lumpfish production has expanded to over 5 million fish per year.
In 2013, MOWI (formerly Marine Harvest) approached NMC to ask if they could source mature lumpfish brood stock and several fish were caught and spawned naturally. The resulting larvae were reared to 15g size using Artemia nauplii followed by specialised marine diets in several recirculating systems specifically designed by the company for lumpfish production.
The company now employs 10 staff who were recruited locally and trained by NMC personnel. Today the farm supplies 850,000 vaccinated fish for stocking on MOWI's farms in Scotland.
JURASSIC SEA FARMS LTD (JSL)
Seaweed has long been known as a food, source of fertiliser and health food with medicinal benefits. It has been cultured for several decades in Asia and is much used in the local cuisine. Until recently Europe has not been a major producer of seaweeds and most of the production came from manual and mechanical harvesting of natural populations.
Since 2015, increasing quantities of seaweeds such as sugar kelp ( Saccharina latissima) dabberlocks (Alaria esculenta) and oarweed (Laminaria digitata) have been cultured from spores which not only saves the natural environment from damage but produces a cleaner and purer product.
The spores are allowed to grow on lengths of twine which are wound around submerged longlines of several hundreds of meters in length. 'Seeded lines' laid in the late autumn/early winter will be ready for harvesting in late spring after which the seaweed is either sold fresh/frozen or dried.
In addition, the company are looking at growing shellfish species such as King scallops (Pecten maximus) and Pacific oysters (Crassostrea gigas) alongside the sea weed culture to see if there are any synergistic benefits in growth rates.