Introduction by Everett Johnson with highlights from Stephanie Boyd’s The Plasticene Era: Parts 1 and 2 – TSFMag Jan and Feb 2018.
Editor’s Note - It’s been a year now that we began encouraging readers to practice better plastic management in everyday live and especially on the water. We are probably all guilty (unknowingly perhaps) to some degree, of contributing to micro-plastic pollution in the marine environment. To get everybody’s attention as we head into a new year of conservation effort and greater stewardship, we thought it might be useful to reprint some of Stephanie’s original work that helped launch this whole plastic management campaign. It’s complex in some ways, the same as the ecology of our estuaries is complex in many ways. So, as my college professors often warned; “Pay attention…this will be on the test.” The test will be how well we as recreational anglers can modify our own actions and influence those of others.Several broad classes of plastics are used in packaging: polyethylene, polypropylene, polystyrene, polyethylene terephthalate, and polyvinyl chloride. They are high-volume usage plastics and consequently, these in particular have high likelihoods of ending up in the ocean environment. However, only about half of these plastics float; the rest sink. So estimating the amount of plastics in the oceans through surface debris collection seriously underestimates the total extent. Even though plastic is the primary ingredient of marine debris, microplastics are under-researched due to difficulties in assessing their distribution and abundance.
In general, microplastics fall into one of two categories. Primary microplastics are produced intentionally, like microbeads or plastic production pellets. Secondary microplastics are small pieces degraded from larger plastics. Globally, primary microplastics have been added to a variety of personal care products – including toothpastes, shampoos, facial cleansers and moisturizers, cosmetics, and shaving products – for reasons such as emulsion stabilization (preventing oil and water from separating), viscosity regulation (adjusting a fluid’s resistance to flow), and skin conditioning. Microplastics are also added to industrial cleaning products, such as scrubbers for removal of rust or paint, and pellets are used in production of plastic consumer goods. Some surprising yet common sources of microplastics include synthetic textiles, tires, road markings, and marine coatings.
Another large source of microplastics is the degradation of plastics on beaches, resulting in microcracking and creating microparticles that are carried into water by wind or wave action. Knowing that microparticles are commonly generated on beaches highlights the importance of beach cleaning as an effective mitigation strategy. The removal of larger pieces of plastic debris from beaches before they degrade much can considerably reduce the microplastics that end up in the ocean. Beach cleanup, therefore, can have an ecological benefit far beyond improving beach aesthetics.
Deep-sea sediments have only been sampled a few times, so data is fairly preliminary at this point. In 2012, sediments and coral were collected from deep-sea locations at depths up to two miles in the Northeast Atlantic Ocean, Mediterranean Sea, and Southwest Indian Ocean. Microplastics were identified in all samples, at an average abundance of 13.4 pieces per 1.7 ounces of sediment. Given the extent of deep-sea regions and how little we’ve explored them thus far, these sediments might hold one piece of the puzzle of the “missing plastics,” unaccounted for tons of microplastic waste that we haven’t found but that should be in the world's oceans.
Microplastics’ small size makes them appealing to a wide range of organisms in benthic and pelagic ecosystems. In some cases, a creature’s feeding mechanisms can’t discriminate between prey and plastic, especially if there is a predominance of microplastic particles mixed with planktonic prey items. And when you’re filtering 20 to 50 gallons of water a day, who’s to say whether that one-millimeter speck is a copepod or a pellet? Clean plastic microbeads have been commonly used in zooplankton feeding research, so there is no doubt they are ingested, and that they can affect the habits of zooplankton. However, no one knows if any warning signals exist that might discourage the ingestion of ‘dirty’ beads by at least some of the species likely to ingest them.
Fibers of monofilament plastics (sourced to fibers of trawls and fragments of plastic bags) have been found in the intestines of the commercially valuable Norway lobster (Nephrops norvegicus). Normal digestive processes apparently can’t eliminate all of the filaments. Field-caught brown shrimps and farmed bivalves had microplastics in their digestive system as well. The identification of microplastics in commercially harvested organisms that are consumed whole (guts and all) highlights the potential human health issues. Based on estimates of the average consumption of mollusks by European consumers, the average person could ingest between 1,800 and 11,000 microplastic particles per year.
Some of the earliest studies noting ingestion of microplastics by wild-caught fish include coastal species from the USA and the UK. Estuarine fish affected include catfish (Ariidae, 23% of individuals examined) and drums (Scianenidae, 7.9% of individuals examined). Slightly lower amounts of ingestion were found in freshwater and marine fish collected from watersheds of the Gulf of Mexico. A total of 51 fish species from 17 families were examined. Ingestion of microplastics was widespread, with individuals from 65% of species (herbivores, invertivores, and omnivores) showing ingested microplastics.
In general, the public and private sector awareness of the potential negative ecological, social, and economic impacts of microplastics is much less developed than for more visible litter. However, in response to growing concerns from the scientific community, Austria, Luxembourg, Belgium, Sweden, and the Netherlands issued a joint statement to the European Union Environment Ministers, calling for a ban on microplastics in personal care products. Bans on microplastics in cosmetic products were also enacted in Illinois, California, and New York, and the Microbead-Free Waters Act of 2015 was finally signed into US federal law in January 2016. Engagement and education at all levels of society (public, government, and private sector) is necessary to effect positive change. With our current resources, it is virtually impossible to remove microplastics from the sea without simultaneously removing similarly sized organisms, like plankton, and subsequently disrupting the ecosystem further.
Wastewater treatment systems fail at filtering out microplastics because of their small size. The best plan, for now, is tackling the multitude of microplastic origins, and that requires addressing the problem at its source – newly engineered materials and smart design, for example, such as clothes that shed fewer fibers or washing machines equipped with filters. And to be successful, these efforts must be supported by legislation and actionable policies that force real change. As pro-plastic consumers, we are responsible for adapting our behaviors and increasing our waste management efficiency. Turning our plastic soup back into the bountiful sea is a challenge we must accept.