Microplastics permeate every ocean environment and are ingested by marine animals from zooplankton to whales, with welfare implications across the food web.
Fish and seabirds with microplastic-filled stomachs experience false satiation, eating less food while feeling full, causing progressive malnutrition. Physical blockage from accumulated plastics impairs digestion and can cause organ damage. Chemical compounds absorbed onto plastic surfaces transfer to animal tissues causing endocrine disruption and immune effects. Seabird parents that feed plastic fragments to chicks cause them to die of starvation in nests full of plastic rather than food. The scale of microplastic harm extends from individual suffering to ecosystem-level collapse of the food web that supports all marine life.