Shark populations have declined significantly due to the high global demand for shark products. Three-quarters of oceanic shark species are currently at risk of extinction. In addition to high demands for shark fins, liver oil, and meat, the deliberate or accidental mislabeling of products that contain sharks means that well-intended consumers may be unknowingly contributing to the problem.

Cosmetics and companion animal food often contain shark products such as squalene. However, this information is not always specified in the product labeling. Instead, the labels may use generic terms such as “ocean fish,” “whitebait,” or “white fish” in their ingredient list. This misleads consumers and takes away their ability to make informed and sustainable choices.

A DNA-based testing method, known as mini-DNA barcoding, has been adapted to detect small pieces of shark DNA in highly processed products. Researchers applied this technique to examine the presence of shark meat in 45 companion animal food products from 16 different brands. While the items were sold in Singapore, they were produced, canned, or packaged in Thailand.

Most of the products listed “fish,” “ocean fish,” or other vague ingredients, while a few listed salmon or tuna. None of the tested products listed shark as an ingredient, but nevertheless, researchers found that 45 of the 144 examined pet food samples (31% of the tested products) contained shark DNA. With the help of these DNA sequences, researchers identified nine different shark species in tested samples.

The most frequently identified species included the blue shark (7 occurrences), silky shark (5 occurrences), and whitetip reef shark (4 occurrences). While blue sharks are listed as near threatened by the International Union for Conservation of Nature (IUCN), silky sharks and whitetip reef sharks are both classified as vulnerable species. The silky shark is also listed under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) Appendix II. This listing aims to control the trade of silky sharks to avoid their overconsumption.

Companion animal food industries may use shark meat for its economic advantage. Sharks are frequently captured for their fins, and once removed, the rest of the shark’s body loses its financial value. Companion animal food industries may take advantage of this low-cost meat as a substitution for higher-value products to increase their financial gain, but the authors believe the likelier explanation is the increasing fishing pressure these animals are subjected to.

While researchers tested a large sample of products, the full diversity of shark species cannot be captured in a single study. Moreover, even though researchers detected the presence of shark DNA in 31% of the samples, they could not identify the exact species of sharks in all cases. It is also possible that the mislabeling of products goes beyond shark meat and extends to other vulnerable species.

Surprisingly, concealing the presence of shark meat in companion animal food is neither illegal nor mandatory. However, failing to provide this information takes away an animal guardian’s ability to make informed choices about purchasing food for their companion animals. Unintentionally, when guardians purchase these products, they are contributing to the profitable shark trade and increasing the risk of their global extinction.

The decline in shark populations can seriously impact the stability and function of oceans. The disruption of these ecosystems may in turn amplify the devastating effects of climate change. Since 1970, the oceanic shark and ray population has declined by 71%. Providing accurate labeling for beauty products and companion animal food can help us make informed choices and discourage unjust fishing practices. It’s also important for animal advocates to educate consumers about how often sharks are used in products without their knowledge, because this information is still largely unknown.