Freshwater (pre-smoltification/juvenile fish)
RSPCA welfare standards for farmed Atlantic salmon 27 September 2015
* indicates an amendment
FW 6.5 The grader must be suitable for the size and type of fish.
FW 6.6 All staff must be fully trained and competent to use the chosen grading system.
FW 6.7 Parr must be able to hold and adjust their position in the water easily.
FW 6.8 When dealing with more than individual fish below 5 grams in weight that require culling, they must be put
into an anaesthetic mixture as prescribed by a vet.
FW 6.9 * Individual fish over 5 grams in weight that require culling must be humanely dispatched using a
FW 6.10 Measures must be in place to prevent fish escaping.
FW 6.11* All tanks must have individual nets/cleaning equipment.
In some adverse environmental conditions it may be necessary to temporarily withdraw feed to avoid
compromising the welfare of the fish through the increased risk of de-oxygenated conditions arising, for
example, during an algal bloom. This withdrawal period must be:
a) kept to a minimum
b) recorded in the VHWP (see H 1.1).
FW 7.2 Nets used in freshwater lochs must be managed hygienically.
FW 7.3 Deterioration of water quality due to fouled nets or over feeding must be avoided.
FW 7.4 The stocking density in freshwater enclosures must not exceed 8 kg/m³.
FW 8.1 Visual checks and observations must be made for several weeks during the period prior to smolting
(silvering, swim pattern, shape).
As a guide, the RSPCA recommends the use of the smolt scoring system as amended, of
C. Findlay, of the Fish Vet Group Inverness.
1 Parr marks clear, light coloured back, flanks green, belly yellow, no silvering.
2 Parr marks fading, back and fins light, flanks starting to silver, belly yellow.
3 Parr marks faint, back and fins darkening, flanks silver, belly whitening.
4 Parr marks very faint, dark back, yellow only around fin bases and operculum,
5 Parr marks gone, back dark, dark margin to fin edges, flanks silver, belly white,
silvering colour dominant.
FW 8.2 The smoltification process must be closely monitored for several weeks as detailed in the Veterinary
Health and Welfare Plan (see H 1.1).