Northern gannets nest in large colonies on rocky coastal sites and forage at sea by plunge-diving. Plastic pollution entanglement in nest material is causing increasing injury and death at major UK colonies.
Plastic entanglement in gannet nests causes a particularly distressing welfare harm: birds become progressively constrained as plastic rope tightens around legs or necks with movement, causing ischaemic injury and ultimately limb loss or death by constriction. The injury develops slowly over days to weeks rather than causing immediate death, meaning affected birds suffer prolonged distress in their breeding colony. Chicks are also affected: plastic in the nest can entangle developing birds that are unable to escape. Nest removal by conservation volunteers at accessible sites provides direct welfare benefit to birds that would otherwise suffer entanglement injury. The ultimate solution requires reduction of plastic in the marine environment: fishing gear lost at sea and plastic packaging that reaches the ocean are the primary sources of nest plastic for gannet colonies.