Low fish numbers
Australian Fur Seals eat fish and squid. If fish and squid numbers are reduced, fewer will be available for the seals. Fish and squid numbers may be reduced by toxins and diseases, changes in water quality, reductions in prey (zooplankton and smaller fish) and over-fishing by humans.
In 1995 and 1998, a disease killed millions of pilchards across southern Australia. Although Australian Fur Seals don’t eat many pilchards, they eat the fish that eat pilchards.