As you bite down into a delicious piece of fish, you probably don’t think about what the fish itself ate — but perhaps you should. More than 50 species of fish have been found to consume plastic trash at sea. This is bad news, not only for fish but potentially also for humans who rely on fish. Fish don’t usually die as a direct result of feeding on the enormous quantities of plastic trash floating in the oceans. But that doesn’t mean it’s not harmful for them. Some negative effects that scientists have discovered when fish consume plastic include reduced activity rates and weakened schooling behavior, as well as compromised liver function.
Most distressingly for people, toxic compounds that are associated with plastic transfer to and bioaccumulate in fish tissues. This is troubling because these substances could further bioaccumulate in people who consume fish that have eaten plastic. Numerous species sold for human consumption, including mackerel, striped bass and Pacific oysters, have been found with these toxic plastics in their stomachs.
It is well known that plastic trash poses a serious threat to marine animals, but we are still trying to understand why animals eat it. Typically, research has concluded that marine animals visually mistake plastic for food.While this may be true, the full story is probably more complex.
Sniffing out the role of smell
Olfaction (smell) is a very important sense for marine animals, including fish. Sharks can smell minute quantities of blood over long distances, which helps them find prey. And scientists believe that salmon’s sense of smell helps them navigate up rivers to spawn in the specific tributaries where they were born. Fish may use their sense of smell in behavioral contexts including mating, homing, migrating and foraging.
Reducing plastic pollution :
Our main finding was that plastic debris is probably confusing for marine consumers because of both its appearance and its smell. That’s a problem, because if plastic looks and smells interesting to fish, it will be very hard for them to discern that it is not food.This study also suggests that our consume-and-dispose culture is coming back to haunt us via the fish we eat. The next big question that it raises is whether plastic-derived contaminants can be transferred from plastic-eating fish to fish-eating humans.
This article was originally published on theconversation.com.