Case Study: Atlantic Salmon
The earliest Atlantic salmon aquaculture began in the 19th century United Kingdom. By the 1960s, sea cage culture was first used in Norway to raise Atlantic salmon to marketable size. The successes encountered in Norway led to the subsequent development of salmon aquaculture in Scotland, Ireland, the Faroe Islands, Canada, the United States, Chile and Australia (5).
Atlantic salmon production began in the 1970s in North America as an industry with a small number of entrepreneurs using ocean net pens in the Pacific Northwest. Opposition developed around concerns over environmental impacts and prevented industry expansion. Production of 17 000 tonnes in 2008 was valued at USD 45 million.Today, North American salmon aquaculture mainly features Atlantic salmon on both the east and west coasts (5).
Most farmed salmon consumed in the United States comes from Canada, Norway, the United Kingdom and Chile. Domestically, the states of Maine and Washington also operate salmon farms.
The Atlantic salmon production cycle is a complex process, occurring in both freshwater and seawater. The following figure illustrates the major steps in culturing Atlantic salmon.
Methods of harvesting the Atlantic salmon vary, but the fish are generally starved for up to three days beforehand. The salmon are crowded into holding pens using sweep nets and are either pumped from the holding pen alive and then transported to a slaughter plant or are slaughtered on the side of the holding pens.
The figure below highlights (in orange) the main countries that use aquaculture to produce Atlantic salmon (Salmo salar).
Global aquaculture production of Atlantic salmon current exceeds 1,000,000 tonnes. The major markets for farmed Atlantic salmon include Japan, the European Union and North America. The figure below highlights the positive trend in increasing Atlantic salmon production from aquaculture.
Despite the potential economic benefits of an increasing trend in worldwide salmon production through aquaculture, the method has been a source of controversy for many groups and organizations, particularly because of the potential negative effects it may have on the environment and wild fisheries. Of particular concern are issues with biological pollution (or the effects of escaped farmed salmon in the wild), the use of fishmeal and fish oil for feed production,exotic species and pathogen invasions, and nutrient pollution and chemical pollution (i.e. antibiotics, pesticides).