Organic waste in farming of salmon 149
2009). Systems for drying sludge are theoretically able to reduce the water
content to 20%. The sludge is rich in nitrogen, phosphorus and minerals (Del
Campo et al., 2010). Because of this, there is interest in finding pathways to
valorise it for re- use.
By- products from traditional grow- out farming remain in the sea (Figure
8.1). Aside from ensilage (dead fish), nothing is collected, and, with the
salmon living in open nets, the organic waste is released into the local coastal
ecosystem. We do not consider processing waste from the grow- out phase,
because it is not collected in traditional cage systems. By- products from
processing plants (blood, innards, heads, etc.) differ considerably from the
waste streams from salmon production (Figure 8.1). We also do not consider
waste from the slaughter of the fish because this has similar valorisation pathways to slaughterhouse waste, discussed in Chapter 7.
However, the literature on salmon production has thus far predominately
focused on the grow- out phase (Asche, Guttormsen et al., 2013; Asche et al.,
1999; Asche & Roll, 2013). Except for Sandvold and Tveterås (2014) and
Sandvold (2016), little research has been conducted in relation to the juvenile
phase. Even less attention has been given to new and sustainable applications
for the increased volumes of collected organic waste in this industry. Therefore, this chapter analyses current valorisation pathways for the sludge from
land- based production of juvenile salmonids. As the industry reorganises their
production process in a more sustainable direction, some new challenges and
opportunities appear concerning the handling of organic waste from landbased systems.
8.2.4 Environmental regulation and historical innovation in salmon
production
Norwegian legislation and regulations for freshwater fish production have
changed since the late 1970s, but not dramatically. As with the grow- out
farms, the production of juveniles is highly regulated, and one needs a licence
to legally operate in this sector. A number of requirements must be satisfied
to obtain a juvenile licence, including access to a sufficient supply of fresh
water, prevention of escapees, safe discharge of wastewater, as well as health,
environment and safety requirements for the employees. Juvenile production
has traditionally been restricted by the maximum number of units that can be
produced each year, and maximum production varies by farm depending on
different environmental concerns. Currently, given licences place no restriction on the number of units produced, but do place a maximum on the withdrawal of freshwater as well as a maximum on the discharge of wastewater.
Beginning in 2017, however, the Norwegian Ministry of Trade, Industry
and Fisheries instituted a “traffic light” system that gives a green, yellow or
red assessment to geographical areas based on losses caused by sea lice. Only
in green areas may firms increase production at sea; in yellow areas, production increases are prohibited and, in red areas, firms must decrease production
2009). Systems for drying sludge are theoretically able to reduce the water
content to 20%. The sludge is rich in nitrogen, phosphorus and minerals (Del
Campo et al., 2010). Because of this, there is interest in finding pathways to
valorise it for re- use.
By- products from traditional grow- out farming remain in the sea (Figure
8.1). Aside from ensilage (dead fish), nothing is collected, and, with the
salmon living in open nets, the organic waste is released into the local coastal
ecosystem. We do not consider processing waste from the grow- out phase,
because it is not collected in traditional cage systems. By- products from
processing plants (blood, innards, heads, etc.) differ considerably from the
waste streams from salmon production (Figure 8.1). We also do not consider
waste from the slaughter of the fish because this has similar valorisation pathways to slaughterhouse waste, discussed in Chapter 7.
However, the literature on salmon production has thus far predominately
focused on the grow- out phase (Asche, Guttormsen et al., 2013; Asche et al.,
1999; Asche & Roll, 2013). Except for Sandvold and Tveterås (2014) and
Sandvold (2016), little research has been conducted in relation to the juvenile
phase. Even less attention has been given to new and sustainable applications
for the increased volumes of collected organic waste in this industry. Therefore, this chapter analyses current valorisation pathways for the sludge from
land- based production of juvenile salmonids. As the industry reorganises their
production process in a more sustainable direction, some new challenges and
opportunities appear concerning the handling of organic waste from landbased systems.
8.2.4 Environmental regulation and historical innovation in salmon
production
Norwegian legislation and regulations for freshwater fish production have
changed since the late 1970s, but not dramatically. As with the grow- out
farms, the production of juveniles is highly regulated, and one needs a licence
to legally operate in this sector. A number of requirements must be satisfied
to obtain a juvenile licence, including access to a sufficient supply of fresh
water, prevention of escapees, safe discharge of wastewater, as well as health,
environment and safety requirements for the employees. Juvenile production
has traditionally been restricted by the maximum number of units that can be
produced each year, and maximum production varies by farm depending on
different environmental concerns. Currently, given licences place no restriction on the number of units produced, but do place a maximum on the withdrawal of freshwater as well as a maximum on the discharge of wastewater.
Beginning in 2017, however, the Norwegian Ministry of Trade, Industry
and Fisheries instituted a “traffic light” system that gives a green, yellow or
red assessment to geographical areas based on losses caused by sea lice. Only
in green areas may firms increase production at sea; in yellow areas, production increases are prohibited and, in red areas, firms must decrease production