Many imported seafood products are produced in systems that rely on antibiotics, antifungals, and preservatives banned or restricted in Australia. Random surveillance regularly catches them at the border.
South-east Asian shrimp and Chinese tilapia industries have repeatedly been flagged by health authorities for use of antibiotics including chloramphenicol, nitrofurans, and malachite green — all banned for food production in Australia. Surveillance by FSANZ and DAFF Imported Food Inspection routinely detects residues.
Sulphites are commonly used to preserve imported prawns and prevent black-spot. They're a major allergen — Australian law requires them to be labelled. If a menu doesn't disclose, you can't know.
Many imported aquaculture systems operate in heavily polluted waterways — heavy metals, industrial runoff, untreated effluent. Australian aquaculture sites are independently audited for water quality and located in Class A waters.