Atlantic and Pacific mackerel are fast-swimming, schooling fish caught in vast quantities. Their welfare in industrial fisheries and as aquaculture feed fish is largely unconsidered.
Like herring, mackerel are caught in enormous quantities by methods that cause massive scale suffering. Pelagic trawls drag fish for hours before retrieval; purse seines compress schools causing crowding and oxygen depletion. Mackerel on ice suffocate slowly — a process taking many minutes. Their high metabolic rate means they deteriorate rapidly and suffer acutely from oxygen deprivation. As aquaculture feed fish, mackerel are ground into meal with no welfare consideration. Climate change is altering mackerel distribution and triggering geopolitical conflicts over fishing rights, further driving unsustainable harvest pressure.