What types of plastics are the biggest problem?
Plastic pollution in general is detrimental to animals. The tiniest marine critters introduce tiny plastic microbeads into the food chain, which are subsequently consumed by predators and end up in the stomachs of bigger fish. Seabirds consume plastic that is roughly the same size and shape as the fish that often makes up their diet, including cotton buds, cotton swabs, and small toys. Animals that typically eat shrimp, like the albatross, sift through the plastic and choose the pink, brown, and red bits, thinking these are their favorite food. Plastic trash of all sizes is an issue. Numerous species of marine life can be transported by floating debris, such as buoys, abandoned boats, and pieces of docks or pontoons, which can spread invasive species or diseases to new areas and disrupt the local ecosystem.
This albatross carcass was one of scores recently found packed with plastic trash on Midway Island, where scientists estimate 99 percent of the birds have some plastic in their stomachs. (Photo by Chris Jordan)
Pollutant Bio-Accumulation in the Food Chain
The food chain already contains plastic. Microplastics are ingested by animals. Those microplastics are also ingested when they are consumed. The ‘trophic transfer’ of microplastics is the term used to describe it. Microplastics can pass across the food chain since animals consume one another. What happens to the poisons and chemicals linked to these polymers is the key concern. Plastic has a propensity to bond with contaminants when it enters the environment. Through a process known as bio-accumulation, the attached toxins to plastic that travels through the food chain can also travel and build up in animal fat and tissue. Additionally, plastic is frequently produced with the addition of chemicals to give it certain desired properties. Even when the plastic is inside the body of an animal, these substances may seep from the plastic.
Food Chain Toxins
Toxins like PCBs and dioxins may enter the food chain through a variety of different channels, not just plastic. In comparison to exposure from the animals’ regular diet, the contribution of plastic to toxin bioaccumulation is fairly minimal. Because toxins in the body have attached themselves to the plastic, animals that pass it out may be cleansing their bodies. The situation with plastic additives is different. These chemicals have not accumulated in the food chain over time, unlike PCBs and dioxins. When Japanese scientists discovered a specific flame retardant in the tissues of seabirds, they knew for sure that it had formerly been applied to eaten plastic.
Amount Of Animals Affected By Plastic
It would be very impossible to quantify how many individual creatures will be impacted by plastic, but the total would likely be in the billions. There have been attempts to count the number of impacted species. The number of marine species that consume plastic or become entangled in it has doubled since 1997, from 267 to 557, according to study conducted by Dutch scientists in 2015. With the qualification that only a very small number of animal species have been studied, this number is already above 2000. To say nothing of the impact of plastic on the food chain, it is much harder to identify whether plastic poses a threat to the existence of a particular species.
Sources Microplastics 101: In the Environment, In the Air, In your Food Plastic In Food Chain A Plague of Plastics