Genetic identification of threatened shark species in pet food and beauty care products

Abstract

Contemporary global demand for shark commodities such as fins, meat, and liver oil, is arguably the main driver of shark overexploitation trends observed in the last three decades. Shark are most commonly traded for their fins to be used in different Asian countries as a soup delicacy. Nevertheless, shark meat trade has increased substantially in the last decade, while liver oil trade is still largely unknown. Shark liver oil is highly valuable in the cosmetic industry as a moisturizer, while shark meat is directly consumed in a large number of countries but the whole extent of its uses is unknown. Here I used a multiplex mini-barcode PCR protocol to identify traces of shark DNA in beauty care and pet food products, in order to identify them to the genus and/or species level. All products tested for this study were not labeled as containing elasmobranch-based ingredients. I tested 87 pet food products, 63% amplified successfully, and 70% of those were identified as the Endangered shortfin mako shark. I also tested twenty-four cosmetics, where 3 (12.5%) amplified successfully, containing blue shark, scalloped hammerhead and blacktip shark. This study highlights the need for more labeling controls, since shark populations could benefit if consumers have the alternative to choose whether or not to purchase products containing threatened shark species in order to decrease the global demand.