Gill Health in Farmed Salmon: A Critical Welfare Issue

Gill health problems are among the most significant welfare issues in Atlantic salmon farming, affecting breathing, disease resistance and survival.

Key Facts

Gill disorders affect up to 80% of salmon in some production cycles at various severity levels
Causes include amoebic gill disease, bacterial gill disease, cataracts and physical damage
Sea lice attach to gill tissue causing local damage and inflammation
Regular gill scoring provides early detection of deteriorating gill health
Water quality management is the primary prevention strategy for most gill conditions

Welfare Considerations

Gill health is fundamental to salmon welfare because gills perform the essential function of oxygen extraction from water. Compromised gill function causes chronic hypoxia, forcing fish to work harder to obtain adequate oxygen with consequent welfare impacts throughout the body. Amoebic gill disease causes progressive tissue destruction leading to respiratory distress that worsens with exercise or warm water. Regular gill health monitoring through scoring and post-mortem examination provides the data needed to identify problems early and intervene before welfare is severely compromised.

What You Can Do

Support salmon certification schemes with gill health monitoring requirements
Advocate for gill health scoring as a mandatory welfare outcome measure in salmon regulations
Choose salmon from farms with documented gill health management protocols
Support research into gill disease prevention and treatment approaches in Atlantic salmon