These days when you go to a restaurant and order the fish or browse the seafood case at the supermarket, what you might not know is that the fish or shellfish you are looking at have in all likelihood consumed some form of microplastics. And now, scientists around the world are racing to understand the relationship between the ingestion of microplastics by sealife and its possible effects on human health.
Right now, science lacks the evidence to say if microplastics (5 millimeters to 100 nanometers in size) are affecting fish on a population size level so we can't say for sure if our food supply is in danger. But what we can say is that microplastics are ever-present in many fish species and this has the experts worried. A myriad of studies have shown that microplastics can be found in more than 100 aquatic species, in fresh and saltwater, both wild caught and farmed. Of those, more than 50% could end up on the dinner plate. Popular food species like cod, mackerel, sardines, mussels, and shrimp have all been found to contain some form of these microplastics in their system. Though the science might not be definitive enough yet to say if these microplastics in fish are affecting human health, just the thought of it leaves a sickening feeling in one's mind.
What is most disturbing is the thought that as you go up the food chain, toxins associated with plastic transfer tend to bioaccumulate in fish tissues. The food web starts with the smallest of creatures like zooplankton who ingest the tiny microplastics thinking they are forms of phytoplankton. This zooplankton is then eaten by fish like sardines and anchovies. Next in line is the foodfish like mackerel, cod, flounder, or snapper. Even further up are the swordfish, tunas, mahi-mahi, and sharks. While not on the menu, apex marine mammals like seals, dolphins, orcas, and whales are extremely susceptible to these higher levels of toxins in their prey as well.
Here is an infographic that visually shows how easy it is for these microplastics to get into the food web.
Another way microplastics get into the human food chain is through sea salt production and ingestion. Sea salt is made by evaporating ocean water and generally has very little processing so, along with all the beneficial minerals it contains, the downside is that it contains microplastics, too. A recent study analyzed 39 salt brands (including sea salts) from 21 countries including ones available in the US, China, and Europe. Of those 39 brands, 36 of them were found to contain microplastics! It turns out that those brands from Asia had the highest quantities of microplastics in them. This is not surprising as Asia, particularly Indonesia, is a hotspot for plastic pollution and just goes to show how pervasive the problem of microplastic pollution is around the world.
At 4ocean, we are on a mission to clean up the ocean and capture these plastics at their source before they ever have a chance to make it into the open ocean to become microplastics. We are cleaning the ocean and coastlines 7-days-a-week and the launch of our Ocean Plastic Recovery campaign, to collect plastic at high-impact areas in the Carribean and Bali, is just the first step. You, too, can get involved by purchasing a 4ocean bracelet which pulls a pound of trash from the ocean and coastlines and joining us on our next 4ocean Cleanup near you.
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The ocean plastic crisis may seem like a relatively recent phenomenon with how much attention it's received over the last decade. However, this situation extends decades beyond modern-day — and the inception of plastic itself stretches even further. Understanding the history of ocean plastic pollution gives us a glimpse into how this material became so pervasive and how we might learn from past behaviors.