Revealing the Species Behind the Label: DNA Testing of Cooked Shark Fillets in Western Australia

Context Poor labelling of shark products is a global problem that hampers sustainable fisheries and limits consumer choice. Aims We conducted a detailed assessment of mislabelling and species composition in cooked ‘shark’ products from Western Australian fish and chip shops. Methods COI sequencing was used to identify species in cooked ‘shark’ fillets. Key results We identified 11 shark, 2 chimaera and 3 teleost species in 167 products from 132 shops. Most products were labelled ambiguously (56%) or mislabelled (35%), and only 26% provided origin information. Products labelled ‘shark’ (53%) mostly contained dusky, gummy or whiskery sharks. For species-specific labels, most products (92%) were advertised as ‘gummy’ or ‘bronze whaler’ and identified as gummy, whiskery or dusky sharks. Because these species have similar prices, mislabelling likely reflects complex commercial fishing operations and supply chains. Overall, species composition differed from products tested in other Australian states. Only one sample involved a species in a ‘threatened’ category under Australian IUCN assessments. Conclusions Cooked shark products sold in Western Australian fish and chip shops showed a high incidence of ambiguous labelling and mostly contained dusky, gummy and whiskery sharks. Implications Our findings underscore the need to strengthen seafood labelling legislation in Australia.