Biofilters are bioreactors (also called biocatalysts) that make use of highly complex metabolic activities of various microorganisms to clean water or air. Here “clean” means, above all, to eliminate or render harmless various pollutants or toxic substances. The term “filter” in the sense of holding back or removing unwanted material is not appropriate in so far as biofilters in fact only transform the substances.
When evaluating the environmental sustainability of aquaculture operations water consumption and water discharge quality are important criteria. Today water usage is governed by more or less strict rules almost everywhere in the world. For aquaculture, this often means the obligation to clean and treat the water discharge in such a way that natural ecosystems remain unaffected.
A shrimp farming project is currently underway in Riga, Latvia, producing high quality organic shrimp in a Recirculating Aquaculture System (RAS). The project was launched in May 2014 and uses an intensive biofloc RAS. This system recirculates 100% of the water and has zero discharge, causing no negative effect on the external environment and ensuring the quality of organic shrimp production.
Although the price of fishmeal tended to fall during the course of 2014, and further progress was made with regard to reducing the share of fishmeal in aquafeed, the situation on the fishmeal market is still tense. Supply remains scarce and prices are still high. In spite of this, most feed producers are optimistic that supplies to aquaculture will be secure in future, too.
The rising concern about the environment is encouraging fish farmers to look for sustainable ways of producing fish. Geothermal water is one of them. The use of hot water stored underground enables the farming of fish in colder climates all year round compared to conventional fish farming. Heat from the earth’s interior is a limitless resource that can be utilised to farm fish. Many regions are already employing geothermal energy as an affordable, easily available and sustainable alternative to fossil fuels. Geothermal activity is concentrated around the Pacific Ocean and the Pacific Plate, from Indonesia, the Philippines and Japan, to Alaska, Central America, Mexico, the Andes and on to New Zealand. Europe also has access to geothermal water, from hot water geysers or in the depths of under the earth’s surface. Hence, the use of geothermal water in aquaculture depends on the geographical location of the country.
When asked what organic aquaculture is, consumers usually understand the farming of aquatic organisms without the use of antibiotics or chemicals, whereby attention is also paid to the preservation of biodiversity, and to protection of the ecosystems and human life. Organic certifiers and other professionals in this area set the bar much higher, however. They often only recognize what they themselves have rubber-stamped because it is only with their own “organic labels” that business is worthwhile.
Next to feed, oxygen is the most important factor for determining the success of an aquaculture enterprise. Sufficient quantities of oxygen in the water ensure that the fishes grow well and stay healthy. Oxygen encourages their appetites and general well-being. It can even lessen the impact of temperature induced stress. That is why all fish farmers take particular care that their fishes grow under optimal O2 conditions.
Poland has many advantages in both extensive and intensive aquaculture. The country has the largest area of carp ponds and the greatest carp production potential in Europe; its fish-processing industry is one of the most developed and it has a well-developed education system for aquaculture and fisheries.
Lithuania’s fishery and aquaculture sector makes up less than 0.5% of its GDP, but the sector will see steady growth in coming years. Pond fish farming is the predominant form of aquaculture, but the increasing implementation of closed aquaculture systems (CAS), as well growing numbers of small and medium enterprises, will help create jobs, especially in the rural areas.