Today, aquaculture is focused on meeting consumers’ demand for food. Since this demand increases each year, the number of farmed species is also on the rise.
There is a variety of production systems. They range from systems integrated into the aquatic environment to ones in facilities that recreate and control optimal fish farming conditions. Each species has its own characteristics, to the point where some types of fish farming have their own names: salmon culture (referring to salmon farming), carp culture (if we’re talking about carp), trout culture (in the case of trout), etc.
Integrated systems are used, for example, to farm mussels, clams and oysters, which is done directly in the sea, on sandy bottoms, in floating structures or ones supported at the bottom. In Spain, the best-known example is the use of rafts in the Galician rías. With these systems, farmers breed the animals and take advantage of the favourable natural conditions for their growth.
In other instances, the natural environment is also used, but with greater control. Floating cages in the sea or in lakes keep fish in enclosures where they are provided with food and population growth is maintained. A good example of this is trout culture, in which the habitat of trout is replicated in ponds and canals with flowing water.
Other production systems that recreate natural breeding conditions are marine farms, which are large aquariums isolated from the environment. These facilities use technology to circulate the water, keep it in good condition, and control the growth of the farmed species.
There are also the so-called aquaponics farms, which use a joint production system for aquatic plants and animals. The objective of aquaponics is to create a cycle in which the different farmed elements make beneficial use of one another. Basically, it is a method in which plants grow in an aqueous solution with nutrients instead of in soil. These nutrients come from the waste generated by fish. By using the waste as natural fertiliser, the plants become water purifiers.
What is aquaculture like around the world?
According to the FAO (Food and Agriculture Organization of the United Nations), Asia is the world’s top region for aquaculture. China is responsible for nearly two-thirds of global production. India, Indonesia, the Philippines, Vietnam, Japan and Chile are other leading countries.
In Spain, almost 30% of the annual catch comes from aquaculture, with volumes of almost 343,000 tonnes a year, of which 80% correspond to mussels, (270,000 t/year); followed by sea bass (21,000 t/year), sea bream (13,000 t/year) and rainbow trout (12,500 t/year). This production generates value of 450 million euros in a sector that employs nearly 18,000 people (the majority of them are self-employed).
This data, provided by the Ministry of Agriculture, Fisheries and Food, confirms that the aquaculture sector is essential to ensure the sustainable growth of fishing and of the blue economy.