01. Plastics come from fossil fuels
At the core, plastics are made of fossil fuels through an energy intensive and pollution- (water, air) heavy process, often in low socioeconomic and minority regions. Throughout their lifecycle, plastics have a significant carbon footprint, accounting for 3.5% of global greenhouse gas emissions, and of that, 90% comes from production processes (OECD, 2024).
02. Chemical attributes of plastic
Plastic are hydrophobic, meaning water-hating, and attract other hydrophobic chemical compounds in marine environments. Plastics act as a sponge and a transportation vector for persistent organic pollutants (POPs) like DDT and PCB (Jambeck et al., 2015) and pathogens (Bowley et al., 2020).
03. Lifespan of plastics
Plastic is made of fossil fuels, composed of long carbon chains that are extremely difficult to break. As a result, plastic does not readily degrade and can last anywhere between 500-1,000 years in our environment. In marine environments, degradation speed decreases further in habitats with lower UV and colder temperatures, decreased wave action, and changes in both pH and salinity (Hocker et al., 2014; Wadsö and Karlsson 2013).
04. Pollution rates
Today, we produce over 400 million tonnes of plastic waste annually (UNEP 2024), with projections to increase in the near term future. It is estimated that 4-15 million tonnes of plastic enters our oceans every year, however, research shows that as production increases, pollution increases at similar rate (Cowger et al. 2024). Plastic accounts of 80% of debris found in the ocean (UNESCO 2022), making it the most prolific and overwhelming majority of debris we encounter.
05. Common types of plastic pollution
Single-use plastic makes up 60-95% of marine plastic pollution. Below are common types of plastic found in the ocean and examples of each:
- Polyethylene terephthalate (PET) – water bottles, packaging
- High-density polyethylene (HDPE) – shampoo & bleach bottles
- Low-density polyethylene (LDPE) – bags, packaging film
- Polypropylene (PP) – chip bags, bottle caps, rope
- Polystyrene (PS) – meat/poultry trays, protective & peanut packaging
06. Pathways to the ocean
It is estimated that only 9% of the plastic produced is recycled (Geyer et al. 2017), and as a result, much of it ends up in waterways via rivers and effluent from coastal populations (Jambeck et al. 2015). In addition to rivers and effluents (e.g. storm water), microplastics can travel via the water cycle, being transported with water molecules to clouds and return to the surface via snow, rain, etc. (Bowley et al. 2020).
07. Plastic in the environment
In the ocean, plastics are ubiquitous across global waters, found in surface, pelagic, benthic waters, and substrates. Plastic fragmentation and eventual degradation occur when plastics are exposed to physical and chemical factors like wave action, temperature, wind, UV radiation, salinity, pH, and dissolved oxygen (Andrady, 2017; Wadsö and Karlsson 2013; Urbanek et al., 2018). It is especially difficult to determine degradation rates due to differences in polymer/chemical compositions and relative new-ness in human history (~ 75 years!).
08. Microplastics
Microplastics are small plastic particles ranging 1 μm – 5 mm in size. They can either be produced as microplastics or larger plastics can break apart into microplastics over time. Microplastics in the ocean was first documented in 2004. Due to their small size and ubiquity, microplastics are ingested by organisms from multiple functional groups including suspension feeders, planktivores, detritivores, and carnivores (Thompson et al., 2004; Wright et al., 2013; Frias et al., 2014; Van Cauwenberghe and Janssen, 2014; Avio et al., 2015; Palmer and Herat, 2021).
09. Impacts on marine animals
Plastic exposure has been shown to affect marine organisms mechanically due to the physical structure (Wright et al. 2013) and chemically due to the reactivity of attached toxics (Paul-Pont et al., 2016). If ingested by marine animals, plastic can cause gut blockages, lacerations, ulcerations, secondary infections, starvation due to a false sense of satiation, and partial or complete digestive system blockages (e.g. Laist 1997; Derraik 2002; Stephanis et al., 2013). Potential secondary effects such as hormone disruption, reproductive impairment, immune system impairment, and other disease developments are also inherent risks of plastic ingestion (Li et al., 2016; Nabi et al., 2022).
10. Bioplastic, biodegradable plastic, compostable plastic
Bioplastics are derived from renewable biomass rather than fossil fuels, including veggie fats and oils, corn starch and woodchips. While this material has the word “bio” in it, not all bioplastics are biodegradable nor do they degrade any more readily than normal plastic.
Biodegradable plastics are fossil-fuel based plastics that have been engineered to degrade, often through the addition of chemicals. There is no timeline on the degradation process, and bioplastics can persist in the environment like traditional plastics.
Compostable plastic (e.g. polylactic acid, PLA) is biodegradable, made of plant materials, and will degrade into soil conditioning material in industrial composting environments (EPA 2023).
11. Low recycle rates
Less than 10% of plastic is recycled globally every year. The low recycling rate is in part due to either loss to the environment (millions of tonnes annually) or being transported long distances just to be burned or buried (Geyer et al. 2017). In 2016, waste pickers were responsible for collecting over 50% of total recycled plastic (Lau et al. 2020). Another reason for low recycling rates is the lack of information about the types of plastic, which can decrease quality by mixing waste streams (Leslie et al. 2016).
12. Recyclability (and downcycling)
Recycled plastic is generally made into items such as furniture, roads, packaging, bottles, and clothing. Generally, plastics that can easily be recycled, such as hard PET or HDPE, can be mechanically recycled (washed, ground, and made into a new product). Conversely, hard-to-recycle plastics, such as LDPE or film can sometimes be chemically recycled (polymer structure is changed and converted). Often, plastic is downcycled, or made into something less structurally strong, and has a finite lifespan on the market.
13. How plastics impact human health
Chemicals can leach from plastic-wares including water bottles, knives and skin products to enter our bodies. Some of these chemicals are known to be tied to health issues such as endocrine disruption, weight gain, insulin resistance, decreased reproductive health, products. However, little research has been done on the impacts of plastic on human health – much of what we know is based on chemical compositions and impacts on other animals (UNEP 2024).
14. Policies are pushing plastics out
There is sufficient evidence that policies can lead to reduced plastic production and consumption. For example, implementation of a plastic bag policy leads to a reduction in bag use by 33-96% (Schnurr et al. 2018). In 2019, the Conference of the Parties (COP; UN framework) passed an amendment to the Basel Convention, placing restrictions on the international movements of hazardous waste, including plastic. Extended Producer Responsibility policies are gaining traction and place the responsibility of a product‘s post-consumer stage on the producers (companies) rather than consumers (us). In 2022, 175 nations convened and agreed to adopt the first legally binding global plastic treaty. As of 2024, the UN Environment Programme and International Negotiating Committee is still developing the treaty.
15. How plastic became so prolific
Mass production began after WWII, and plastic quickly replaced heavy, breakable, and expensive items. Industries have grown dependent on plastic, especially plastic films, for its flexibility, durability, and inexpensive price (Sivan, 2011).
Pelagic Impact 