Наука & Природа
янв 1, 2018
Aquaculture states itself, daily, as an important alternative to traditional forms of fish supply, producing about half of all fish consumed in the world, this is the reason why it is considered today a strategic sector.
By ALFREDO MIRANDA
Nowadays, more and more people depend on fisheries and aquaculture for their food and income. However, harmful practices and mismanagement are threatening the sustainability of the sector, warns FAO (United Nations Organization for Food and Agriculture).
Still according to FAO, we must not forget that aquaculture already represents more than half of all the fish for human consumption which, in 2014, has reached a new maximum of 20 pounds per capita annually.
For the first time, world aquaculture production (including aquatic plants) exceeded the obtained by catch, reaching 101.1 million tons, representing 52% of all production of fish (195.7 million tons). World production amounted to 167.2 million tons, of which 93.4 million came from capture and 73.8 million from aquaculture.
For most researchers, aquaculture offers enormous potential to meet demand for food associated with the growth of the global population, contributing to improve the diet of many people.
However, researchers do not cease to warn that to continue to grow in a sustainable way, the sector must become less dependent on the wild fish for feed and introduce greater diversity of species and practices in aquaculture farms.
For example, smaller fish can be an excellent source of essential minerals when it's totally consumed. However, due to consumer preferences, as well as other factors, it has been observed a tendency for the production of larger species, whose bones and head are often discarded.
For investors and scientists, the growth of aquaculture is considered a key factor to boost the levels of global consumption of fish per person. In the 1960 decade, the value was in average 9.9 kg/inhabitant/year. The average grew to about 14.4 kg in the 90's and in 2014 this value reached 19.7 kg/inhabitant/year.
International trade has played an important role so that there is an increasing number of choices for consumers of fish. Among the Portuguese-speaking countries, Brazil is expected to lead the increase in fish consumption per person in the next decade, as part of Latin America. The other regions are Asia, Oceania and the Caribbean.
The Latin America and the Caribbean will present a major expansion in aquaculture production that can get the 3.7 million tons in 2025, a growth of 39.9% in relation to 2013/15, during which were produced on average 2.7 million tons per year.
Now, globally, aquaculture production should grow until reaching 195.9 million tons in 2025, an increase of 17% compared to the production of 2013/15, of 166.8 million.
One cannot omit the fact that 2014, have registered for the first time, an increase in production in captivity in respect of catches by fishing. The product from the fishing always dominated the consumer's table, but today, 50% of the fish consumed worldwide comes from aquaculture. This means that, in the year 2025, the world will produce 29 million tons more of fish than that in 2013/15, most of that increase will happen in developing countries through aquaculture.
THE BLUE REVOLUTION
The new "Blue Revolution", which has provided cheap shrimp, salmon and tilapia and vacuum packed to supermarket freezers, brought with it many of the problems generated by agriculture on land: habitat destruction, water pollution and related problems with food safety.
In early 1980, vast extensions of mangrove coastlines (typical vegetation of wet land) were razed to build aquaculture units. Pollution caused by aquaculture (a putrid mix of nitrogen, phosphorus and dead fish) is now a widespread hazard in Asia, where are located 90% of aquaculture fish. To keep the fish alive in cages, some highly populated Asian fish farmers use antibiotics and pesticides of prohibited use in United States, in Europe and in Japan.
Aquaculture units from other regions of the globe are also not free of problems. Modern salmon industry, which over the past three decades have installed cages populated and filled with salmon in pristine fjords from Norway to Patagonia, has been plagued by parasites, pollution and disease. Salmon aquaculture units of Scotland lost almost 10% of its workforce in 2012, due to an infectious outbreak; in Chile, it is estimated that the infectious anaemia has caused losses of 1.4 billion euros in salmon aquaculture since 2007.
The problem is not in the ancient art of aquaculture itself, but on its intensification. The Chinese farmers began to raise carp in rice paddies for at least 2,500 years ago. However, the current aquaculture production represents 42 million tons per year and the bordering fish cages the banks of rivers, lakes and seas. The fish farmers introduce us birders varieties of carp and tilapia of rapid growth, feeding them with concentrated fish flour to maximize its growth.
But, as the researchers argue, there is a simple solution to these problems: creating fish in tanks installed on the ground and not in cages in a lake or the sea, because if we don't let the oceans in peace and quiet, "mother nature is going to make us pay with high interest rates".