Few consumers who pick up a can or bag of pet food containing fish will stop to consider where the contents come from or what species they are made from.
But research suggests we should be thinking about what goes into the highly processed foods we feed our cat or dog.
When researchers in Singapore analyzed 144 samples of pet food for sale in the country, they found that 31 percent contained shark DNA, some from species listed as vulnerable.
The most common was the blue shark (prionace glaucous), then the silky shark (Carcharhinus falciformis) and the whitetip reef shark (Triaenodon obesus).
“None of the products specifically mentioned shark as an ingredient, listing only generic terms, such as ‘ocean fish,’ ‘white fish,’ and ‘white bait,'” study authors Ian French and Dr. Benjamin Wainwright wrote in Frontiers in Marine Sciences.
Other research found that about one in three seafood samples is mislabelled, raising concerns about “shellfish fraud” and leading one operator in the sector to describe the fishing industry as dysfunctional.
Scientists investigating the DNA barcode of seafood include Professor Stefano Mariani of Liverpool John Moores University in the UK. The Singapore findings don’t surprise him.
“It’s something that unfortunately happens in many different ways,” he says.
“When you have pet food, it’s usually in a can or a bag. It is like a pulp or pellets. It is very indistinguishable. It has a lot of ingredients and is very processed.”
Determining from which species the ingredients were obtained is not easy. After a few steps in complex supply chains, “information is lost”. Single Harmonized System (HS) codes, which use an international standardized system for labeling traded products, can cover hundreds of fish species.
Often the problems start from the beginning. Sharks can be transshipped from one fishing boat to another, says Francis Neat, a professor of sustainable fisheries management, ocean biodiversity and marine spatial planning at the World Maritime University in Sweden.
“By the time the product enters the point of processing and starts to mix with other ingredients, it probably becomes extremely difficult to have the right checks and balances as to what’s in there,” he says.
“[This] That’s why these DNA methods are the first attempt to understand that or to control the extent to which this is happening.”
When it comes to the pet food analyzed in the new study, the authors suggest that there are conservation concerns about the three main shark species they identified.
They say research indicates blue sharks are “overexploited and should be regulated,” while the International Union for Conservation of Nature lists silky sharks and whitetip sharks as “vulnerable.”
Sharks as a whole have suffered greatly at the hands of humans, with populations having shrunk by 70 percent over the last half century. According to 2021 research cited in the new study, three-quarters of oceanic shark species are threatened with extinction. Fishing is considered its greatest threat.
In this context, Professor Neat believes that pet food manufacturers have a responsibility to ensure that the ingredients they use are sustainable.
“There are ways to do that,” he says. “There are certified fisheries that you could source your products from that provide some certification of the species and the origin of that catch and where it comes from.
“There are national or multilateral agreements, such as the EU, that have a catch documentation scheme that to a large degree ensures that the species is the species that it says on the label.”
DNA testing identifies which species are present in food (be it human food, pet food or farmed fish food) and can indicate whether a certification scheme is working.
The Marine Stewardship Council (MSC), a non-profit organization that sets sustainable fishing standards and certifies food for humans and pets, uses this to validate products sold with their certification.
With the MSC, Professor Neat, who used to be the organization’s head of strategic research, says there is “very good agreement” (over 99 per cent) between how the species is sold and what it actually is, based on its DNA. . .
Not all sustainable fisheries are certified, says Professor Neat, so there are other options for people trying to ensure that the food they or their pets eat doesn’t have conservation implications.
Among the commercial companies offering DNA testing is Norway-based Orivo, which conducted its own evaluation of pet foods and found that 60 percent of products contained undeclared species.
“These were not endangered species, but rather lower priced species, so we suspect financially motivated fraud,” says Erik Fuglseth, Orivo’s chief technology officer.
Mr Fuglseth says there is growing concern about transparency among consumers and as a result also among retailers, brands and manufacturers, but complex supply chains make vigilance important.
“When raw materials, such as fishmeal, are transported long distances through multiple intermediaries, it can often be challenging to monitor whether other sources are intentionally commingled with the raw materials, due to supply and demand challenges. or to maximize profits,” says Mr. Fuglseth.
“We are focused on helping honest and responsible gamers document that their products contain what they claim.
“Our technology is sensitive enough to detect even small numbers of specific species, and can be used as an efficient way to verify the end of complex value chains and thus detect adulteration by endangered species. ”.
In developing countries it can be particularly difficult to have effective surveillance, so the risk is probably greater that the species or origin of the fish is not well documented, according to Professor Neat.
“The problem comes when you have illegality [operators] catch sharks for their fins,” he says. “There is a huge market for shark fins in Asian countries. A lot of that is likely illegal or unregulated.”
The capture of sharks for their fins, which are considered a delicacy, has led to the overexploitation of many species and has even put some in critical danger of extinction.
“There are still many species that are potentially endangered and whose trade is not really regulated. It’s easy to lose track of what’s happening to animals,” says Professor Mariani.
However, he cautions that pet food should not be seen as a key factor in the exploitation of endangered species of sharks. Instead, he says, shark ingredients in pet food — perhaps an oil, for example — may be a byproduct of catching sharks primarily for their fins.
“It ends up with different vendors, different people,” he says. “It is a very complicated exchange. The liver is used for the oil, the cartilage for the materials that give a certain texture. It is distributed.
“Cat food is not a premium product like bluefin tuna. It’s the stuff that’s used for bulking, so the byproduct of these catches ends up in pet food. That doesn’t mean it’s a good thing.”
Updated: March 11, 2022, 6:00 PM