The species of fish used for aquaculture were, at one time, very limited. The first ones used in Europe were carps, imported from China for use in pond culture. The first European aquaculturists were monks whose ‘original technology’ was developed during the Middle Ages.
During this period, the foundation for fish farming was laid. The production of carps in Central Europe was developed by the monks, in or nearby the monasteries, so as to follow the centuries-old law of meat abstinence on Fridays, applicable to all Roman Catholics. In addition, there was the period of Lent, during which eating meat was also prohibited. These mandatory regulations to serve fish only at these time were difficult to overcome when living far from the sea. So the monks started to look into the cultivation of carps for an adequate and continuous supply of animal protein.
Through spectacular excavations during the early 1990s, at the former monastery (12th century) in Trondheim (Norway), evidence was found that even Norwegian monks were involved in carp “production”. The growing understanding and knowledge of the topic, and the positive results obtained, was spread throughout Europe. Even the aristocracy, like Emperor Charles the Great (768-814), started to ask for fish ponds to be built, wherever possible, to overcome the problems of supply and demand for animal protein of the growing European population.
It is in this way that the south-eastern part of Germany and Bohemia – the latter area being nowadays part of the Czech Republic – became the centre of early European carp production during the Middle Ages.
Under stringent obligations to the public, the ruling authorities made building ponds and carp farming a political item. The period of the 15th and 16th century is even today called the “Golden Age” of fish pond-farming.
Trout culture is a little younger; the appearance of the “Treatise on Fysshynge with an Angle” in the Boke of St Alban’s which was published in 1486, which confirmed the long-standing position of trout as the prestige fish for freshwater fishermen. By the 17th century, river stock depletion was a problem and, in 1741, Stephen Ludwig Jacobi established the first trout hatchery in Germany. From this time, anglers started to depend on cultured supplies of stocks to increase, or substitute, the natural trout production. Following the hatcheries used for restocking, the next development was the rearing of young fish to maturity. This took a long time since the first attempts at commercial trout culture were made in the early nineteenth century but it was not until the mid-twentieth century that expertise was strong enough for trout farming a recognisable activity. The development of pre-fabricated feeds, as well as a better understanding of the husbandry requirements, allowed the activity to expand considerably, spreading throughout Europe into every State.
Marine aquaculture required some engineering, primarily for solidly-built floating cages. In addition, logistical problems needed solving. As an example, the transfer of live juvenile salmon - which are produced in freshwater - to the cages in the sea requires special well-boats or helicopters.
For sea bass and sea bream, now produced commercially in the Mediterranean, the key issue for successful farming was the feeding and rearing of the larvae. Once these problems were resolved in the 1980s, this sector has grown very quickly.
The only country with a history of farming eels is Japan, where eel farming has been done for centuries, on a subsistence basis. Commercial farming started around 1820 in Japan while, in Europe, the Italian valli were the first to approach the cultivation of this species and this was the first European country to develop commercial farms. Today, with the advent of water recirculation technology, eel farming is also done in the Netherlands, Denmark, Sweden and elsewhere.
These are not the only species produced in European aquaculture, turbot - cod - sole - catfish - sturgeon - pike - pikeperch and others are either farmed commercially or being developed.
Today, Aquaculture remains the fastest growing food supply sector in the world – estimated at 6%/year by the FAO and now accounts for nearly 50% of the world's food fish supply (FAO).
In 2011, the FAO estimated an average global fish consumption of 18.8 kg per person per year, this means the global demand adds up to 131 million tons. With a stable food fisheries supply of around 67 million tons, this means that 64 million tons have to come from aquaculture. Moreover, with an increasing population forecast, by 2030 the total need will be more than 160 million tons. If global fisheries remain stable, aquaculture production has to grow to 100 million tons!