Bass Rock hosts the world's largest northern gannet colony, with welfare considerations including entanglement in plastic fishing debris used in nest construction.
Gannet colony welfare is shaped by an unusual combination of natural social density pressures and anthropogenic threats. Dense nesting means that injured individuals cannot easily escape neighbour aggression, compounding injury welfare impacts. Chick entanglement in monofilament fishing line incorporated into nests is a preventable welfare and mortality cause — entangled chicks die slowly from circulatory impingement. Bycatch mortality in fishing nets deprives chicks of parents, causing starvation. Monitoring and removal of entangled chicks by licensed wildlife workers is an active conservation welfare intervention.