pet food container endangered sharks are being fed to cats and dogs by unwitting owners, a study has found.
Scientists have found that several brands contain endangered species but only list vague ingredients such as “sea fish”, meaning consumers are often oblivious.
“The majority of pet owners are likely nature lovers, and we think most would be alarmed to discover that they may be unknowingly contributing to overfishing of shark populations,” the authors said. study, Ben Wainwright and Ian French, of Yale-NUS. College, Singapore.
Shark populations are overexploited around the world, with declines of more than 70% over the past 50 years. As apex predators, they are crucial to the balance of the ocean food web, and the disappearance of sharks has impacted seagrass beds and coral reefs.
The sale of shark fins was widely publicized. But a silent contributor, according to the authors, is the use of shark products in everyday items such as pet food and cosmetics.
Using DNA barcodes, scientists tested 45 pet food products from 16 brands in Singapore. Most products used generic terms such as “fish”, “seafish”, “whitebait” or “whitefish” in the ingredient list to describe their contents, with some specifically mentioning tuna or salmon. Others did not indicate fish at all.
Of the 144 sequenced samples, 45, or about a third, contained shark DNA. The most frequently identified species were the blue shark, the silky shark and the whitetip reef shark. The silky shark and the whitetip shark are listed as “vulnerable” in the International Union for Conservation of Nature (IUCN) Red List.
Products containing DNA from sickle weasel, Caribbean sharp pointer shark and sand tiger shark, all vulnerable species, have also been identified.
The authors suggest the meat could come from discarded shark carcasses after the valuable fins are removed, or could reflect a growing trade in shark meat. They’re calling for more accurate ingredient labeling so people know what they’re feeding their pets and where it comes from.
Dr Andrew Griffiths, an ecologist at the University of Exeter, said the latest work followed research by his team and others revealing the presence of shark DNA in food products for human consumption, including including the sale of spiny dogfish and hammerhead shark meat in fish and chips.
For pet food, he said, the lack of rules on specific labeling means a wide variety of vulnerable species could be legally included. “There are no specific rules against that,” he said. “You could unwittingly catch just about any fish.”
Aside from the lucrative shark fin trade, shark meat is generally quite low in value, Griffiths said, and could be a cheap source of protein. “A lot of people don’t want to eat it,” he said. “So you can’t necessarily sell it through other supply chains. It surprises people that these things can end up on their pet’s plate.
The results are published in the journal Marine Science Frontiers.