The trout is a slim fish in the salmon family. In the nature,
trouts can be found in the sea as well as in freshwater. The trout-meat is
highly appreciated and trouts are raised in freshwater dams along many
streams in Jutland. The trouts raised in farms are usually delivered to
freezing and filleting factories for further processing to the consumer
market, to further growth in sea-farms and to “put and take” lakes mostly
present data refer to trouts (200 to 500 g) produced in Danish freshwater
trout farms in 2000 for freezing and filleting for the consumer market.
The trouts are produced in many different ways depending on local conditions,
but the general processes are following: 1) young trouts produced in a
hatchery are put
into a dam 2) the trouts
are fed with trout
feed for a period of 12-18 months, 3) the trouts are caught and transported
alive in water tanks to the trout slaughterhouse.
Data on feed and helping agents consumption as well as emissions to water are derived from literature (Miljøstyrelsen, 2001). Data on electricity consumption are partly based on literature (Landbrugs- og fiskeriministeriet, 1998) and partly based on data collection from 10 farms located in Mid-Jutland. The data collected from farms are based on farmer’s 2000 records.
All production processes in
hatchery as well as in trout dams are included. Consumption of stream water
has not been considered because water is returned to the streams.
Consumption of freshwater for hatchery has not been considered because the
amount is small. Generation of solid waste from e.g. packaging has not been
Medicine is not included.
and helping agents
consumption are derived from 388 farms representing all trout farms in
Denmark. Data on electricity
derived from 10 farms representing 2.5% of the Danish farms. Data on emissions
to water are based on at least 900 measurements in 150 farms and representing
about 40% of trout farms in Denmark. Feed consumption per kg of trout
produced varies only slightly and is considered
to all Danish trout farms. Data on electricity, medicine and helping agents
consumption as well as emissions to water vary significantly from farm
to farm 1) due to different quality and availability of stream water 2)
due to different recirculation and treatment of dam water. In
data are derived from large samples of farms and provide a very representative
national average. However, due to the large variation, the data are not
representative to most individual farms.
is to a large extent determined by the degree of recirculation and treatment
of dam water. The electricity
from almost zero at farms with no water treatment to about 3
kWh per kg trout at farms with comprehensive water treatment.
Landbrugs og fiskeriministeriet (1998). Projekt Bæredygtigt Dambrug. Rapport fra Landbrugs- og Fiskeriministeriet, Strukturdirektoratet. In Danish.
Miljøstyrelsen (2001). Punktkilder - Det nationale program for overvågning
af vandmiljøet - Orientering fra miljøstyrelsen Nr. 13.