Your pet’s food may contain endangered sharks , even if the ingredients on the label don’t explicitly list the word “shark.” Here’s what a recent analysis of commercially produced pet foods has revealed.
A group of scientists from the National University of Singapore conducted a DNA study on samples of 45 pet food products representing 16 brands sold in the country. Shark was not listed as one of the ingredients on any of the labels. However, the researchers found that 31% of the samples contained shark DNA.
The reality is that many pet foods often describe their ocean-based ingredients with generic words like “fish,” “white fish,” or “ocean fish.” The researchers wanted to know if DNA tests would reveal exactly what fish the labels referred to.
Regarding the study at hand, what the scientists did was to analyze the samples with DNA barcodes, which identify species by comparing short DNA sequences with a database of so-called genetic barcodes from the genomes of species. acquaintances. One problem they faced was the destruction of DNA that occurs when food is highly processed. This can happen in many that come canned. To get around the hurdle, the researchers used a technique known as mini-barcoding , which can amplify even small genomic sequences in degraded samples.
Blue sharks ( Prionace glauca ), well known and consumed in Spain under the name of blue sharks , were the most common in the analyzed samples, appearing seven times. This species of shark is not on the list of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), but, according to scientific data, it is overexploited and its capture should be regulated.
Other studies have shown that blue sharks are frequently caught in commercial fisheries, and their presence is high in the shark fin trade in Southeast Asia, the scientists note in the study. Both of these factors could explain why blue sharks end up in pet food, which would prevent carcasses from going to waste.
After the blue shark, the two species that were most detected in the samples were the silky shark ( Carcharhinus falciformis ) and the whitetip reef shark ( Triaenodon obesus ), both included in Appendix II of CITES . Membership in this appendix means that the animal, although it is not on the verge of extinction, does need special control so that international trade does not jeopardize its survival. These controls do not prevent international trade in these animals. What they do is promote sustainable practices so as not to end biodiversity.
Singaporean researchers identified nine species in total, including spottail sharks ( Carcharhinus sorrah ), slant-eye sharks ( Loxodon macrorhinus ), and sand tiger sharks ( Carcharias taurus ). They also noted that 16 samples included DNA from sharks that could only be identified by their genus: Carcharhinus .
While it is true that pet food companies are not required to specifically mention that the meat in their product is shark, the vagueness with which they refer to it on the label means that the owner of the pet does not know exactly what you are buying and whether your decision is promoting certain practices. In fact, the study authors say many pet owners would likely be alarmed to discover that their purchase is likely contributing to unsustainable fishing practices.
As pointed out in the study, published on March 4 in Frontiers in Marine Science , shark populations have decreased by more than 70% in the last 50 years . These declines have been largely attributed to increased fishing. Despite increased public awareness of shark conservation, three quarters of all oceanic shark species are currently considered endangered.
Referencia: French et al. 2022. DNA Barcoding Identifies Endangered Sharks in Pet Food Sold in Singapore. Frontiers in Marine Science. https://doi.org/10.3389/fmars.2022.836941
