The life cycle of farmed salmon List of

The life cycle of farmed salmon

List of contents 1. Facts about salmon production 2. The life cycle of salmon 3. Fish feed 4. Fish farmer – a responsible job 5. Harvesting 6. A popular globetrotter

1. Norway’s major farm animal • Everyone knows about life on a farm. Very few know anything about life on a fish farm • Salmon is our most important farm animal, measured both in tonnes and numbers • Norway produces twice as much salmon as beef, mutton and pork combined • In 2004, Norway produced around 540, 000 tonnes of salmon

2. The salmon’s life cycle • All farmed salmon originate from brood stock and are reared on special farms • Today’s brood stock originated from 40 Norwegian salmon strains, which were collected in the early 1970 s • Since then, salmon have been bred so that they are as suitable for farming as possible Photo: Norwegian Seafood Export Council

Fertilisation • The brood stock are stripped in the autumn and spring. Eggs and milt are removed from sexually mature salmon • Fertilisation is done by mixing the eggs, milt and water. The mixture is then placed in an incubating system • During incubation, water temperature is kept stable and the water is replaced regularly • Newly fertilised eggs must be left to lie undisturbed in the dark to mimic the river bed

Eggs • After around 30 days the eyes of the embryo salmon can be seen as two black spots in the egg • At this stage the eggs may be sorted and transported to other facilities • The temperature determines the length of the incubation period • In water at 8°C, incubation takes approx. 60 days from fertilisation until the egg hatches

Sac fry • The fry are not yet fully developed when they hatch • They get their nourishment from a yolk sac • The fry must be left undisturbed with good support for the yolk sac. If it tips over they may die • When the yolk sac is almost depleted, the fry are moved from the incubators into larger tanks

Weaning • Weaning is a critical phase for salmon, as it must learn to eat • Wild salmon have a high mortality rate. In salmon farming this is less than five per cent • When weaning has started, the fry begin to move • The fish are usually exposed to light 24 hours a day, just like the wild salmon in Northern Norway in the summer. This gives faster growth

Young salmon (parr) • When the yolk sac is depleted, the fish develop dark markings along their flanks – so-called parr markings • The salmon are now called parr and are kept in a freshwater farm • The salmon parr continue to grow in tanks up to smoltification • During smoltifcation the salmon undergo significant physiological changes in order to be able to live in saltwater

Smolt in the sea • After approx. one year in the freshwater farm, the fish are ready for release into sea cages • The salmon are usually 80– 100 g on release and are now called smolt • The fish are transported in fish carriers (well boats) to the sea localities • Smolt are transferred from freshwater to sea water in the spring and autumn

The sea farm • In the sea, adult fish live in net enclosures called cages • The fish farmer keeps a careful eye on the salmon’s development and environment • The salmon are kept in the sea until they reach approx. 4 kg • The production period is from one to two years, depending on the time of release, size and temperature

3. Feeding • Automatic feeding systems are the most common method of feeding the salmon • A feeding system consists of a feed silo, hoses from the silo and a small computer that controls feeding • The farmer also feeds manually, when required and also to keep an eye on life in the cages • The fish are fed different types of feed depending on size, season and growth Photo: Norwegian Seafood Export Council

Composition of the feed • All fish feed is healthy and safe – both for the salmon and for those eating the salmon • The feed mainly consists of natural ingredients such as fatty acids and amino acids from fish oil, fishmeal, vegetable oils and protein, and minerals and vitamins • Astaxanthin in the feed ensures that the fish absorb enough vitamin A and it gives the meat its characteristic pink-red colour. In the wild the salmon gets astaxanthin from small crustaceans • Antioxidants are added to the feed to prevent it from becoming rancid

4. Fish farmer – a responsible job • Much of the work on the fish farm is automated, but good fish farmers are still worth their weight in gold • Like other farm animals, salmon depend on receiving good human supervision and care • Feeding is the most important task of the fish farmer • The fish farmer is responsible for the daily care of the fish and for their health and hygiene. Some of the routines are compulsory by law

Well regulated husbandry • The Norwegian Food Safety Authority regularly controls the health and welfare of the fish • All farms are obliged to have a fish welfare service, which is inspected six times a year • In addition, a public veterinarian visits the farms twice a year • Salmon farming is regulated according to a number of acts and regulations, which protect the welfare of the fish

5. Harvesting and processing • All harvesting is reported to the Norwegian Food Safety Authority • The fish are transported in a fish carrier (well boat) to the harvesting plant, where they are stunned or made brain dead by other means according to governmental requirements, before being bled and gutted • The salmon are cleaned, graded as superior, ordinary and production according to size and quality and then packed in cases for export or further processing. Export of production fish is prohibited Photo: Norwegian Seafood Export Council

6. Popular globetrotter • Norwegian salmon is exported fresh, frozen or processed to more than 100 countries • It is served as sushi in Japan, lucky fish in China and as festive food in Russia • Russia, EU and Japan are the most important markets • All salmon is tagged with the harvesting date, harvesting plan, species and the name of the farm. This ensures good traceability

Healthy, safe and trendy • Health experts around the world recommend that people eat more seafood and especially oily fish such as salmon • Salmon is the favourite fish of young Norwegians • No other fish in the world is subject to such extensive control as Norwegian salmon • Producers and the authorities have a comprehensive system to ensure that salmon is safe food

Would you like to find out more? • Visit www. laksefakta. no • Articles on salmon and aquaculture • Presentations (ppt) and fact sheets • Free key rings • Delicious salmon recipes .