Plastic pollution is killing the ocean’s coral reefs

Adam Chartier, Building and Construction Technology.

Autumn Fetridge, Animal Science.

Kara Duprey, Environmental Science.

The United States and its territories are home to several coral reef systems in Florida, Puerto Rico, The U.S. Virgin Islands, Hawaii, Pacific Islands, and the Garden Flower Banks offshore of Texas in the Gulf of Mexico (Environmental Protection Agency [EPA], 2018, para. 1). The Florida Reef is the third largest barrier reef in the world and has been in decline for the last four decades due to disease, pollution, and rising ocean temperatures (EPA, 2018, para. 16). Hawaii alone houses 60%, over 140,000 acres, of the United States’ coral reefs and is estimated to be worth over $9 billion and contribute several hundred millions of dollars to the economy per year. Commercial and recreational fishing in coral reefs generate $200,000+ per year (EPA, 2018, para. 31-33). However, we may not be able to enjoy the beauty and benefits of coral reefs for much longer as our plastic trash continues to infiltrate and devastate reefs at alarming rate; systematically poisoning, wounding, and infecting coral communities, leaving stark white skeletons in their place. Single-use plastic production releases chemicals that damage corals and the plastics themselves cause disease and physical harm to corals.

The US, thanks to a well-functioning waste management system, only mismanages 2% of its plastic waste. But because of the sheer amount of plastic trash generated by the average American, 2.58 kg per day, the tiny amount of mismanagement adds up to a large amount of garbage entering marine environments. Estimates of plastic pollution entering the ocean in the United States alone range from 40,000 to 110,000 metric tons each year (Jambeck et al., 2015, p. 769). To put the amount of plastic waste being generated into perspective, consider just one of the most ubiquitous single-use plastic items in an American’s life; the plastic shopping bag. The amount of these bags being produced is staggering. An estimated 103 billion plastic bags are used by Americans each year which works out to roughly 319 bags per person (Wagner, 2017 p. 4). Weighing an average of 5.5 grams each (Schiller, 2009, para. 3), the plastic bags used by the United States weigh around 500,000 tons. Even if only 2% of the plastic bags Americans use find their way into the ocean, that is still 10,000 tons, or the equivalent of 73 blue whales made of plastic swimming out to sea each year.

In order to understand why plastic bags in particular are a likely source for marine debris, it is important to know how plastic bags are handled by recycling systems. Recycling plants are better equipped to recycle hard plastic items such as drink bottles, but the film-like plastic of shopping bags tend to clog the machines that sort and process recyclables (Ruiz, 2015, para. 8, American Chemistry Council, 2015, para. 6). Most curbside recycling programs do not allow plastic bags for this reason, and as a result the recycling rate of all of these plastic bags is only 12.3% (Wagner, 2017, p. 4). This means that a significant amount of plastic bags are put in landfills or are just discarded into the environment which gives them the potential to become pollution in the oceans.

Plastic companies have such a high demand to meet that their production factories are constantly running to produce product. Almost all plastics, 99% of them, are produced from fossil fuels such as crude oil (Center for International Environmental Law, 2017, p. 1). The production of just one kilogram (kg) of plastic creates and discharges about 6 kg of Carbon Dioxide (CO2) (Rohrer, 2009, para. 3), and about ⅓ of that is absorbed into the ocean when released (Doney, Fabry, Feely, Kleypas, 2009, pg 16). Since a plastic grocery bag weighs 5.5 grams and on average a single person uses 300 bags per year, that means the average person is responsible for almost 10 kgs CO2 per year. The amount of CO2 generated through bag production is 2.5 billion kilograms, which is the amount of CO2 produced by 500,000 passenger cars in a year. The absorption of CO2 into the ocean has resulted in ocean acidification. Ocean acidification is when atmospheric CO2, like that released from plastic production, combines with water molecules to form carbonic acid and subsequently lowers the pH of the ocean water. Since 1980, pH measurements of ocean water have dropped by about .02 units per decade, making our oceans have the same acidity as baking soda (Doney et al, 2009, p. 1). This may seem like a miniscule amount but means life or death for sensitive species like corals that rely heavily on the ocean’s chemical properties; the increasing acidification of Earth’s oceans inhibits the ability of coral to build up their calcium structure by lowering the availability of carbonate ions, a necessary component of the calcium skeleton (Hoegh-Guldberg et al., 2007, p. 1). An increased CO2 level in the water can reduce the growth of coral through calcification by up to 40% (Hoegh-Guldberg et al., 2007 p. 1). In response to this decreased ability to grow, corals reduce the density of their calcified structure, but this leaves them extremely susceptible to erosion (Hoegh-Guldberg et al., 2007 p. 2).They also divest more of their energy into producing more calcified structure; however this takes energy away from other processes including reproduction and a lower reproduction rate is detrimental to an already decreasing population (Hoegh-Guldberg et al., 2007 p. 2). Ocean acidification caused by rising CO2 levels produced largely by the burning of fossil fuels, as used in plastic production, is dissolving our reefs little by little, leaving them damaged and exposed.

Physical damage is caused to corals by marine debris that gets entangled in coral reefs. Marine debris such as lost and abandoned plastic fishing gear has been well documented as causing physical damage to corals. In a study of 338 corals exposed to the plastic fishing gear, 226 of them, or 69% , were physically damaged (p .1110) Of the 226 damaged corals,  62% of them had fresh tissue loss, which is similar to a wound on human skin (p. 1111). This tissue loss was caused by the gear abrading the coral as the water pushed it across and around the coral. The majority of the fishing gear in this study (over 95% of it) was made of plastic, non-biodegradable material (p. 1109). Plastic bags that are extremely prevalent in our oceans are made out of this same material. They also have this ability to scrape across corals and abrade them or catch and break off branching coral structures. Not only do the abrasions physically damage coral structures, but the wounds can facilitate the invasion of pathogens (Lamb et al., 2018, p. 462).

In this way, plastic pollution poses an even greater threat to coral reefs because plastics are the perfect surface for disease causing microbes to attach to. The plastics carry these microbes with them through the aquatic environment and can end up settling in ecosystems such as coral reefs. Once entangled in the reefs, these plastics wreak havoc. They physically damage corals and  abrade them, creating open wounds. After damaging the coral they expose the coral reefs to the microbes. A study shows that overall likelihood of disease in corals increases from 4% instance of disease in reefs without plastic to 89% in the presence of plastic debris (Lamb et al., 2018, p. 460). Three major diseases of corals increased when coral was in contact with plastic waste; Skeletal eroding band disease increased 24%, white syndromes increased 17%, and black band disease increased 5% (Lamb et al., 2018, p. 461). Black band disease moves across the surface of a coral systematically killing it, leaving a barren white skeleton in its wake, completely wiping out a colony of coral in just months (Florida Museum of Natural History, 2018). White syndromes peel the tissue straight from the coral skeleton, working upward from the base, white syndrome has killed 95% of acropora coral in the Florida Reef, leaving a graveyard of skeletons in its wake (Florida Museum of Natural History, 2018, p. 1). These diseases are not just damaging to the corals, they are fatal and cause rapid death in coral reefs.

The damage caused to coral reefs by plastic bags could be reduced by the implementation of a nation-wide ban on plastic bags in the United States along with the distribution of reusable cloth bags to low income persons. Plastic bag bans have already been implemented in other parts of the world, as has the distribution of reusable bags. There are some economic arguments against plastic bag bans, but alternatives to plastic bags like bags made of cotton, canvas, jute and even woven baskets are all readily available and are much safer for coral reefs (Evans, 2018, para. 3). Just a handful of reusable fabric bags can do the job of all of the plastic shopping bags a person uses once then throws away. Banning plastic bags and encouraging the use of reusable bags nationwide is the best way to protect coral reefs like the Garden Flower Banks.

The need for a national ban on plastic bags, as opposed to focusing on coastal states or even cities is due to the contribution of rivers to oceanic plastic pollution. A study showed that ten major rivers contribute to the majority of trash in the ocean. These rivers are all pass through heavily populated cities and towns and drain into the ocean after collecting litter from these cities (Schmidt et al. 2017, p. 1). While no rivers in the United States made it onto the top ten list; the Mississippi River presents a huge opportunity for plastic and other litter to enter the ocean. The Mississippi River flows through ten states before draining into the Gulf of Mexico. When including all of the connecting rivers, a total of 31 states and two Canadian provinces drain into the Mississippi River (Environmental Protection Agency [EPA], 2016, para. 1). This land area encompasses 41% of the United States and a total of 15% of North America (EPA, 2016, para. 2). A majority of these states are completely landlocked and hundreds of miles from the coasts; but their connection to the ocean is a danger that not many consider and show why ocean pollution is not just a coastal problem. Once dumped into the Gulf of Mexico, plastic waste will entangle in the Flower Garden Banks reefs, and ride the ocean current called the Loop Current eastward down and around Florida and into the Florida Reef. Plastics travel extremely far from where they are initially deposited wreak havoc on corals by damaging them and introducing disease (NOAA, 2013).

The travel of plastic from land to coral reefs is a phenomenon clearly exemplified by Midway, a group of two islands that sit in the middle of the Pacific Ocean. Midway is extremely remote as it is 1,300 miles from the nearest city, Honolulu, Hawaii, and is only inhabited by 40 members of the U.S. Fish and Wildlife Service who stay on the island to protect and monitor its wildlife (Britannica, 2016 ) (Cable News Network [CNN], 2016). It is also surrounded by half a million acres of coral reef (CNN, 2016). Despite how remote Midway is, it is covered in plastic and often referred to as a “plastic island” (CNN, 2016).. Since 1999 the National Oceanic and Atmospheric Administration has removed 125 metric tons of plastic from Midway (CNN, 2016). Nobody used this plastic at Midway or brought it there directly (CNN, 2016).. All of the accumulated plastic on Midway originates from Asia and North America where people disposed of it and it got carried through river systems and discharged into the ocean (CNN, 2016). Ocean currents carried these plastics thousands of miles to the Midway islands and through the coral reefs that surround them.

The United States already has examples of plastic bag regulation that have been adopted at the state level. in November of 2016, California enacted a ban that prohibits most grocery, retail, and convenience stores from offering customers plastic bags that are designed for a single use (California Department of Resources Recycling and Recovery, 2018, para. 1). The effectiveness was apparent almost immediately. During a California Coastal Cleanup Day in 2017, the year after the plastic bag ban went into effect, a recorded 11,847 plastic grocery bags were picked up. Compared to a Cleanup Day in 2010, before the ban, 65,736 bags were collected (Ocean Conservancy, 2017) This represents a reduction of 83% in the amount of plastic bag litter that was picked up off the coasts of California. The conclusion to draw is clear, that the bag ban in California lead to a decrease in the amount of plastic litter that had a chance to become ocean debris. California is proof of not only the feasibility of plastic bag bans, but also of their effectiveness. Bans like the one that is working in California should be expanded and adopted by the country as a whole.

The existing examples of successful plastic bans are impressive, but they are not without struggle. Rwanda had a very positive result from their ban, but issues with stakeholders, and lack of alternatives and enforcement were major struggles for the nation. The legislation was widely criticized for only consulting middle class and wealthy stakeholders and disregarding the poorest sector of the country (UNEP, 2018 p. 61). Along with the conflict, the people of the country felt like they were not given any alternative products to replace the outlawed plastics with (UNEP, 2018 p. 61). This was in part because there was not enough funds delegated to improving recycling technology (UNEP, 2018 p. 61). Due to lack of alternatives as well as lack of enforcement of the ban, citizens illegally brought plastic bags in from other nations and sold them on the black market (UNEP, 2018 p. 61). These conflicts could have completely unraveled the whole project. If the United States is to be successful in reducing the nation’s plastic use, then all of these factors that Rwanda struggled with should be addressed and resolved in order to implement the new law in the most efficient way possible.

Taking the setbacks that Rwanda faced into consideration, we propose that when plastic bags are banned reusable bags are distributed to low income families and elders at no cost. This system yielded positive results in Cambridge, MA and avoided the problems that were encountered by Rwanda. In Cambridge, single use plastic bags have been banned. The effect on the lower class and elderly was taken into account and the city worked to solve the issue surrounding the accessibility of reusable bags for elderly and low income families by collecting and distributing over 8000 bags to families and individuals who needed them (Cambridge Department of Public Works, 2016). 8,000 is a lot of bags for just one city and based upon this number, the amount of bags that would have to be provided to the rest of the country would be pretty big. We recognize that the provision of reusable bags to certain citizens is a big task with financial implications, but by providing reusable bags in tandem with implementing the ban, everybody will have access to reusable options, removing the cost barrier and disincentivizing the start of a black market as in Rwanda. This will effectively stop the use of plastic bags and therefore prevent any more of them from entering the ocean via the U.S.. This preemptive action makes reducing the amount of plastic bags that can enter the ocean and destroy coral reefs a viable course of action for everyone.

Other arguments against plastic bans are largely economic. The claim is that bans on single use plastic shopping bags harm the economy because they threaten the job security of plastic industry workers, hurt the bottom line of stores, and impose an unnecessary cost on consumers (American Progressive Bag Alliance (APBA), 2019). This argument sets up a false dichotomy between the economic benefits of producing plastics (shopping bags in this case) and any alternative that curtails it. The argument requires the assumptions that money not spent producing plastics is lost completely, and money spent pursuing the alternatives is a total waste. These assumptions are not true; for example, money diverted from plastic manufacturing could be used to stimulate new production of biodegradable alternatives. The truth is that plastic pollution threatens the economic productivity of coral reefs and protecting the health of reefs provides greater economic activity to the local communities using them. If plastic companies are favored over coral reefs then, the economy stands to lose the $9.6 billion that activities related to coral reefs produce (Scripps Institution of Oceanography, para. 5). Simply stating that plastic bans hurt the economy ignores the harm done to coral reefs by plastic pollution and ignores the economic benefit of coral reefs. These arguments, made mainly by lobbying groups supporting the plastics industry, show clear bias toward protecting the interests of businesspeople, rely on an oversimplification of the complex issues, and do not adequately refute our position that plastics should be banned in order to protect corals.

The fear that banning single use plastics will cause job losses in the plastic business are also unfounded. Evidence shows that reusable bag companies/industries are growing in the United States and have a positive impact on the job market. Companies such as GreenVetsLA have created a number of jobs in the economy focused on the production of reusable bags created from scrap fabric of the fashion industry, while also employing USA veterans (Hickman, 2013). Green job markets in the United States are growing and contribute to the growing number of jobs available and can counter the potential job loss in the plastic industry (Hickman, 2013). Additionally, a number of plastic bag suppliers are also producers and suppliers of reusable bags (Hickman, 2013). Companies such as Pan Pacific Plastics, Tri Star Plastics, and Command Packaging are all on existing ordinances confirming them as suppliers of reusable bags that meet the standards of being able to be reused at least 125 times, carry 22 or more pounds for more than 125 feet, and be washed at least 100 times (San Francisco Department of the Environment, 2016). Plastic corporations are diversified enough to withstand single-use plastic bans and have the adaptive capabilities to adjust their market and production with a national ban. Coral reefs and their dependent economy do not have this same flexibility. Without coral reefs economies based in tourism and marine fisheries would suffer greatly and have no easy alternatives to makeup for the deficit.

Another concern over banning plastic bags is that non-reusable replacements such as paper bags and biodegradable bags have a larger carbon footprint than plastic bags, meaning that they cause the release of more CO2 during production and transport. These emissions can lead to ocean acidification which harms corals as previously mentioned.Production-wise, paper substitutes take more energy and resources to generate than plastic bags (Bell & Cave, 2011). They also take up more space while shipping and therefore cause more carbon emissions during transport as compared to plastic bags (Bell & Cave, 2011). Replacing plastic bags with reusable cloth alternatives, instead of with paper bags or biodegradable bags, solves this issue. A cloth bag must be used 171 times (Bell & Cave, 2011, p. 6) to equal out the environmental impact of a plastic bag, but a well-made and cared for cloth bag is easily reused that many times. With the average American needing more than 300 shopping bags per year, cloth bags can easily outpace plastic in a short amount of time. In a bag ban situation, customers bring their own reusable bags, so stores do not need to ship enormous amounts of cloth bags to their store beyond the small amounts offered for sale (Bell & Cave, 2011). While cloth bags also have a production cost; fabric needs to be made etc.; most cloth bags are already made of repurposed bags and recycled fabrics (Bell & Cave, 2011). In the short term, production cost of reusable bags may lead to higher carbon emissions, the long term effect of reducing plastic usage will offset the initial harm and help save coral from effects of plastic entanglement from debris that never fully breaks down and hangs around killing for decades.

Plastic pollution in the ocean causes immense harm to coral reefs and a world without coral is a sad one; they contribute a huge amount to the economy, protect shorelines, and are some of the most biodiverse ecosystems. A nationwide ban against plastic bags in the United States, with a plan to eventually ban the top ten single-use plastics, will improve the health and well being of coral reefs. The plastic bag ban will take a big step towards stemming the damage done to coral, but this proposal will not be popular with the public unless there are viable alternatives to cover the gap. As the opposing arguments show, consumers will reject a plastic ban if they just see it as a punishment or as an encroachment on their liberties. Making sure that the public is educated on the impact that the heedless use of plastic has on coral reef is essential, but just as important is providing them with other options so they are not inconvenienced. For plastic bags, this is easy; the alternative is reusable bags. Reusable bags allow consumers to reduce their plastic consumption, since just a handful of bags can serve an entire household in all their shopping needs. Each use of a reusable bag lowers its ecological footprint, and well-cared for bags can last for years. Additionally, alternatives to other plastic products are constantly being developed, giving hope to a more complete single-use plastic ban in the future. Switching to reusable bags and eliminating the use of single-use plastic bags in the United States prevents any further pollution of coral reefs by plastic bags.



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