Seabirds including puffins, terns and kittiwakes depend on forage fish like sandeels. Overfishing of these prey species causes widespread seabird breeding failure, with significant welfare implications for millions of birds.
Seabird breeding failure from forage fish depletion causes welfare harm at two levels: the immediate distress of unsuccessful breeding attempts and the starvation of chicks that hatch but cannot be provisioned adequately. Parent birds making repeated foraging trips that fail to find sandeels experience exhaustion and extended periods of foraging without reward. Chicks that starve in the nest experience progressive weakness and distress before death. The scale of this welfare harm across millions of breeding pairs across the North Sea and beyond is enormous. The causal chain from industrial fishing for fishmeal and fish oil to seabird starvation is well established scientifically. Policy interventions restricting sandeel fishing provide direct welfare protection to seabirds by restoring their food supply.