Farmed Salmon Sea Pen Design and Welfare

Open sea pen design for Atlantic salmon farming significantly affects water flow, stocking density management, and behavioral welfare, with better-designed pens enabling more welfare-positive conditions.

Key Facts

Most Atlantic salmon are farmed in open net pens in sheltered coastal waters
Pen size, depth, and current exposure affect oxygen levels and fish distribution within pens
Deep pens allow depth-using behaviors and more complex physical environments for fish welfare
Semi-closed containment systems reduce sea lice exchange with wild fish and improve water quality control
Voluntary swimming depth distributions reveal environmental preferences that can guide pen design

Welfare Considerations

Salmon sea pen welfare begins with pen design and placement decisions made before fish ever enter the water. Pen dimensions, depth, and hydrographic location determine the range of water quality conditions fish can experience. Large, deep pens in appropriate currents provide better welfare conditions than small, shallow pens in poor-flow locations. Fish welfare in pens is also affected by management decisions including stocking density and feeding. Semi-closed containment systems that control the pen environment more precisely offer welfare advantages but at higher cost. Welfare-positive pen design requires integrating behavioral ecology knowledge of salmon preferences into aquaculture engineering.

What You Can Do

Support salmon products from operations with documented welfare-positive pen design standards
Advocate for pen design requirements in salmon aquaculture welfare certification
Learn about sea pen design and its influence on farmed salmon welfare
Choose certified salmon products that verify physical environmental welfare standards