| Description | Scorea | Action | Severity assessmentb |
|---|---|---|---|
| Normal swimming, behaviour, appearance | 1 | NA | MILD |
| Swimming behaviour | |||
| Bottom swimming | 1 | Check similarity controls | MILD |
| Surface swimming | 1 | Check similarity controls | MILD |
| Surface air gasping | 2 | NA | MILD |
| Vertical swimming | 3 | Cumulative discomfort | MODERATE |
| Swimming in side or supine position | 3 | NA | MODERATE |
| Circle swimming (normal to supine position) | 3 | NA | MODERATE |
| Pigmentation | |||
| Darker colouring | 2 | NA | MILD |
| Appearance | |||
| Tail contraction | 3 | NA | MODERATE |
| Haemorrhages/suggillation | 4–5 | (Consider) HEPc | SEVERE |
| Visible damage to skin and/or fins | 4–5 | (Consider) HEP | SEVERE |
| Reactive behaviour | |||
| Slow compared with control | 2 | NA | MILD |
| Immobile | 2 | NA | MILD |
| Hyperactive swimming after ticking against vessel | 2 | NA | MILD |
| Hyperactive swimming | 3 | NA | MODERATE |
| Other | |||
| Sudden death without previous signs | 2 | NA | MILD |
| Sudden death with previous signs | 2–5 | NA | MILD, MODERATE or SEVERE |
| Irreversible discomfort like convulsions | 4–5 | (Consider) HEP | SEVERE |
a
If an observation is also present on the second or third day in a row, the score is added +1, 4 days in a row +2 and 5 days in a row +3. This may facilitate severity assessment and implementation of HEP.
b
If a combination of observations is present, the severity assessment will be adjusted to the highest severity score of the observations present.
c
HEP = humane end-points.