Freshwater fish farms consist primarily of earth ponds, or basins or canals constructed from concrete, where a continuous water flow-through is maintained from spring, stream, ground or drainage water circulated through airlift systems.
There are a handful of fully recirculated aquaculture facilities (FREA) in Denmark, that produce more fish with less water and less pollution in closed facilities.
The Danish production of freshwater farmed fish is primarily rainbow trout, though eel, trout, pikeperch, carps, pike, perch, Atlantic salmon, sturgeons are also farmed.
The Danish freshwater fish production is currently taking place in about 230 fish farms, primarily Jutland (Danish: Jylland). In 2007, the freshwater fish farms produced approximately 30,000 tonne fish.
Environmental effectsWaste water from freshwater fish farms is a major concern because waste water can negatively impact the environment in the receiving water body.
Large quantities of organic compounds and nutrients in waste water and fish sludge can result in oxygen deficiency in the receiving body of water, and thus result in a decline in water quality as well as the natural biological communities. In addition, wastewater can contain residues of medicine and chemical additives that are added to farms in order to treat sick fish, cleaning of facilities or added as water treatement.
As a result of dams and weirs, channel straightening and other types of stream alterations, fish farms can also cause physical damage to near-by streams. Most fish farmers though, take into consideration the native fish and their migratory pattern by placing fish ladders or the like in order for the fish to pass the dam or weir.
Regulation and environmental protectionIn 1989, the Danish government enforced regulations on freshwater fish farms, resulting in a reduction in discharges of organic materials, nitrogen and phosphor to about half.
Freshwater fish farms are now regulated according to the new Statuary Order for Fish Farms nr. 130 of 8th of February 2012 (In Danish: bekendtgørelsen om miljøgodkendelse og samtidig sagsbehandling), and an environmental approval (Environmental Protection Act chapter 5). Water intake is regulated by the Water Supply Act.
This new statuary order for fish farms combines 3 statuary orders into 1 (statuary order for Fish Farms, statuary order for model type 3 fish farms or similar installations as well as the statuary order for simultaneous processing of permits for freshwater fish farms).
The main goal of the new statuary order for fish farms is to create incentives for the fish farmers to produce more fish while reducing their the environmental pollution.
Expansions and other changes of a freshwater fish farm, which will lead to an increase in pollution, have to be approved according to chapter 5 in the Environmental Protection Act.
Environmental approvals of freshwater fish farmsAll freshwater fish farms were, by 1 January 1999, obligated to apply for an environmental approval according to Environmental Protection Act Chapter 5. In the Environmental Protection Act Ch. 5, each fish farm in Denmark is regulated based on their present environmental condition, more so than is the case in the Statuary Order for Fish Farms (dambrugsbekendtgørelsen).
The municipality that is associated with each fish farm reaches the final decision on environmental approvals as well as the fish farms water abstraction approvals. In addition, the municipalities also carry out inspections. Decisions reached by the municipalities can be filed at the Nature Protection and Environmental Board of Appeal.
The Danish Environmental Protection Agency is the prime enforcement authority of legislation regulating freshwater fish farms, of which includes accessing and preparing guidelines for authorities to regulate the development of fish farms.
Read more about farming of freshwater rainbow trout in Denmark (pdf, 1.6 MB)
Danish Order on environmental permitting and concurrent case management with regard to freshwater fish farming (pdf file)
Find information on Danish measures to promote eco-innovation and increase knowledge about environmental technologies.Read about Eco-inovation here