150 H. N. Sandvold et al.
at sea (Ernst & Young, 2018). As such, the political landscape is evolving to
address environmental concerns.
The Danish Environmental Protection Act regulates freshwater fish farms
in Denmark. Regulations were introduced in 1987, and included water use
and discharge, as well as waste handling. Theoretically, the regulations
focused on nitrogen, phosphorus and organic matter in the effluent, although
these proved problematic to reliably measure. The regulations instead focused
on feed ratios, which were strict and curtailed aquaculture development,
except for fisheries using new water technology, which have dramatically
improved the feed ratios (Paisley et al., 2010). The 2004 Fisheries Act gives
the Ministry of Food, Agriculture and Fisheries authority to regulate fisheries.
The Ministry also has a goal of expanding production, but as most suitable
freshwater locations have already been used, it means that RAS will be an
increasingly important technology in Denmark (Paisley et al., 2010).
The increase in production volume in salmon farming in recent years has
exacerbated the environmental challenges. As a response to these issues, the
industry is now considering and testing different strategies for changing the production, waste handling and related technologies. RAS technology is increasingly replacing the traditional flow- through systems in juvenile production of
salmon (Badiola et al., 2012; Bergheim et al., 2009). The system was developed
in the 1970s in Denmark, out of small- scale laboratory equipment used to study
living fish. The system was first applied to salmon smolt production as a lowercost alternative to flow- through systems, which required more energy to heat
the water. Additionally, RAS was seen as an attractive alternative to circumvent
siting and regulation barriers on flow- through systems, because environmental
risk factors such as escapees and polluted water spills are minimised using this
technology. RAS uses 90–99% less water than flow- through systems, which also
reduces energy consumption for heat. In order to recycle the water, solid waste
(principally fish faeces and some feed residues) must be mechanically removed
as soon as possible in order to prevent the build- up of bacteria that cause anoxic
conditions. A biological filter is also used to clean the water for re- use.
Related to the organic waste, the individual Norwegian hatcheries have
different restrictions in relation to their effluent. The fish farms are responsible for treating their waste in a responsible manner, yet there is no nationally
required practice regarding the treatment of the outlet water. The differences
in the disposal of sludge are primarily related to three different factors:
(1) where they are located (north or south), (2) their age (when the hatcheries
had their licences granted and (3) which technology they use; flow- through
system or RAS. Restrictions tend to be lower in the northern regions of
Norway than in the southern because the concentration of the farms is lower
in the North and the following environmental impact will be lower. The
older farms (from the 1980s) have fewer restrictions placed on the effluent,
and very often still use a flow- through system. However, many of these are
now closing down or being upgraded. All new farms have strict restrictions
requiring waste management and emissions, and they use the RAS.
at sea (Ernst & Young, 2018). As such, the political landscape is evolving to
address environmental concerns.
The Danish Environmental Protection Act regulates freshwater fish farms
in Denmark. Regulations were introduced in 1987, and included water use
and discharge, as well as waste handling. Theoretically, the regulations
focused on nitrogen, phosphorus and organic matter in the effluent, although
these proved problematic to reliably measure. The regulations instead focused
on feed ratios, which were strict and curtailed aquaculture development,
except for fisheries using new water technology, which have dramatically
improved the feed ratios (Paisley et al., 2010). The 2004 Fisheries Act gives
the Ministry of Food, Agriculture and Fisheries authority to regulate fisheries.
The Ministry also has a goal of expanding production, but as most suitable
freshwater locations have already been used, it means that RAS will be an
increasingly important technology in Denmark (Paisley et al., 2010).
The increase in production volume in salmon farming in recent years has
exacerbated the environmental challenges. As a response to these issues, the
industry is now considering and testing different strategies for changing the production, waste handling and related technologies. RAS technology is increasingly replacing the traditional flow- through systems in juvenile production of
salmon (Badiola et al., 2012; Bergheim et al., 2009). The system was developed
in the 1970s in Denmark, out of small- scale laboratory equipment used to study
living fish. The system was first applied to salmon smolt production as a lowercost alternative to flow- through systems, which required more energy to heat
the water. Additionally, RAS was seen as an attractive alternative to circumvent
siting and regulation barriers on flow- through systems, because environmental
risk factors such as escapees and polluted water spills are minimised using this
technology. RAS uses 90–99% less water than flow- through systems, which also
reduces energy consumption for heat. In order to recycle the water, solid waste
(principally fish faeces and some feed residues) must be mechanically removed
as soon as possible in order to prevent the build- up of bacteria that cause anoxic
conditions. A biological filter is also used to clean the water for re- use.
Related to the organic waste, the individual Norwegian hatcheries have
different restrictions in relation to their effluent. The fish farms are responsible for treating their waste in a responsible manner, yet there is no nationally
required practice regarding the treatment of the outlet water. The differences
in the disposal of sludge are primarily related to three different factors:
(1) where they are located (north or south), (2) their age (when the hatcheries
had their licences granted and (3) which technology they use; flow- through
system or RAS. Restrictions tend to be lower in the northern regions of
Norway than in the southern because the concentration of the farms is lower
in the North and the following environmental impact will be lower. The
older farms (from the 1980s) have fewer restrictions placed on the effluent,
and very often still use a flow- through system. However, many of these are
now closing down or being upgraded. All new farms have strict restrictions
requiring waste management and emissions, and they use the RAS.