Capture-based aquaculture of cod

Bent Magne Dreyer
Norwegian Institute of Fisheries and Aquaculture Research
Tromso, Norway
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Bjorg Helen Nostvold
Norwegian Institute of Fisheries and Aquaculture Research

Tromso, Norway
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Kjell Oyvind Midling
Norwegian Institute of Fisheries and Aquaculture Research
Tromso, Norway
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Oystein Hermansen
Norwegian Institute of Fisheries and Aquaculture Research
Tromso, Norway
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Dreyer, B.M.; Nostvold, B.H.; Midling, K.O.; Hermansen, O. 2008. Capture-based aquaculture of cod. In A. Lovatelli and P.F. Holthus (eds). Capture-based aquaculture. Global overview. FAO Fisheries Technical Paper. No. 508. Rome, FAO. pp. 183–198.

 

SUMMARY

The concept of capture-based aquaculture (CBA) of cod is not new, in fact Norwegian fishers delivered their first live cod for marketing in Grimsby (United Kingdom) in the early 1880s. Currently, there are concerns as the Norwegian quota for the wild capture of cod is at an all time low and the seasonal differences in catch quantity are large. In addition, consumers prefer fresh high quality products. To meet these challenges, capture-based aquaculture of cod has received increased attention.
Capture-based aquaculture of cod differs from the CBA of most other species in that it is not based on juvenile catches. Instead cod from traditional fisheries, i.e. cod which is more than 4 years old is kept alive for approximately 6–8 months prior to being slaughtered and marketed as a variety of fresh cod products. Cod CBA is marginal and accounts for only one percent of the total Norwegian cod production. However, its importance is expected to increase as the methods for catching and keeping the fish alive improve. Additionally, increased quality per se and biomass growth through fattening in aquaculture is expected to contribute to increased attention. In many respects, cod CBA is similar to that of the bluefin tuna, but is at present smaller and with less socio economic effects.
The biology and migratory patterns of cod imply that it is only available for short periods of time in different areas along the coast; during spawning (February to April) and when it feeds on capelin (April to June). The traditional harvesting of wild cod is carried out over a short period of time and in limited areas where the fish is easily accessible. This coastal catch, performed by small- and medium-sized vessels, is highly dependent on favourable weather conditions.
Even though technology has made it easier to locate and catch the fish even in difficult weather conditions far from the coast, there are still seasonal differences regarding both quantity and quality. The traditional seasonal pattern of fishing for cod creates significant challenges in product development and marketing for the processing industry. These variations in supply make it difficult to plan the production and choose production capacity. Additionally, in a market that demands predictability both in volume and quality, lucrative contracts may be lost because it is difficult to commit to long-term delivery of supplies. CBA is looked upon as a promising concept for meeting the two most important challenges in a growing fresh-seafood market by reducing the uncertainty of volume, quality, delivery and documentation.
Capturing cod in periods of the year where it is easily accessible and storing it in the sea lowers the uncertainty of supply and opens the door for commitments through long-term contracts with those parts of the market that demand stability in volume and quality. In addition, new research shows that allowing the fish to restore physiologically for 12 to 24 hours after capture, reduces the capillary blood in the muscle and therefore results in a whiter fillet.
Traditional, full cycle farming of cod as a third alternative to bringing cod to the market is emerging and the production in 2006 exceeded 10 000 tonnes live weight. This is similar to the salmon farming industry, while capture-based aquaculture is rooted in the traditional industry capture and processing of wild cod. The Norwegian strategy is to apply all three concepts, i.e. traditional catch, capture-based aquaculture and farming to meet the challenge of consistently supplying the market with high quality fresh products all year round.
In order to establish and encourage CBA of cod, several challenges and regulations must be met. A new legislation was launched in January 2006 that included criteria for vessels approved for live capture. The legislation’s emphasis is on improved post-harvest animal welfare as the main tool to increase survival rates. As there is a strong link between welfare and quality, this strategy is likely to be adopted by the industry. Furthermore, the use of CBA is based on the development of different weaning and feeding regimes.