Seabirds mistake floating plastic for food, accumulating plastic in their stomachs and feeding it to chicks, causing malnutrition, blockages, and death across millions of individuals annually.
Seabird plastic ingestion causes welfare harm through multiple mechanisms. Plastic fragments occupy stomach space, causing false satiation that reduces feeding drives while providing no nutrition. Gut blockages prevent digestion and cause pain. Parents feeding plastic-filled chicks inadvertently cause the same harm to the next generation. The individual welfare impacts — malnutrition, painful blockages, secondary infections from sharp plastic fragments — are experienced by millions of individual birds whose suffering is invisible to the humans who produced the plastic waste responsible. The scale of this welfare harm, distributed across millions of seabirds globally, makes plastic reduction one of the most significant interventions for wild animal welfare available.