How Plastics are Literally Changing Our Oceans

When we talk about ocean plastic pollution, images of giant floating masses of plastic the size of small states immediately come to mind. Fishing nets clogged with litter instead of fish and beaches piled high with trash are visual reminders of how plastic is overwhelming and outnumbering our natural resources.


But there’s an even more dire situation than just the sheer volume of plastic pollution ensnaring fishing lines and cluttering beaches. Plastic has the ability to leech toxic chemicals into the environment, and when masses of trash enter our ocean, they begin to change the chemistry of the ocean in dangerous ways.


The Sources of Ocean Plastic Pollution


Ocean plastics come from a variety of sources. About 20% of plastics that end up in the ocean come from ships and offshore buildings (for example, oil rigs). The rest of the plastics that find their way to the ocean do so by winds and rivers that pick up litter and eventually dump it into the ocean.


Ocean currents then sweep the plastic out to sea, eventually collecting them into “gyres” where the currents meet. The largest is the Great Pacific Garbage Patch, which is larger than the state of Texas. These garbage patches collect millions of pieces of plastic trash, which float in the ocean and are exposed to harsh environmental elements that slowly erode the plastic. As these plastics erode, they break down into smaller elements. As this happens, another problem begins to emerge as well.


The 12 Toxic Chemicals in Our Oceans


There is a type of chemical we like to call “persistent organic pollutants” or POPs. These chemicals can pass from animal to animal through the food chain, increasing their concentrations with each pass.

Environmentalists have identified 12 of these POPs in our oceans:


  • Aldrin
  • Chlordane
  • Dichlorodiphenyltrichloroethane (DDT)
  • Dieldrin
  • Endrin
  • Heptachlor
  • Hexachlorobenzene
  • Mirex
  • Toxaphene
  • Polychlorinated biphenyls (PCBs)
  • Polychlorinated dibenzo-p-dioxins (dioxins)
  • Polychlorinated dibenzofurans (furans)

Most of these chemicals have been banned for years in countries around the globe due to their links to serious human ailments like infertility, hormonal imbalances, and other diseases. However, they can all still be found floating in our oceans. The question is, how?


Chemical Hitchhikers


When plastics break down, they first simply become smaller and smaller pieces until they fit the definition of microplastics (plastics that are 5mm in diameter or less). When exposed to the extreme elements in the open ocean, such as heat from the sun, salt and other chemicals in the ocean, and wind, the chemical structure of plastics can begin to change. Some plastics start to leech chemicals, but others become more porous and able to absorb chemicals.


Many of these POPs were already released into the water systems before their eventual bans. But decades have passed since they’ve been banned, which means most of these chemicals should have broken down in the harsh environment of the ocean. Unless, of course, they could find suitable shelter.


Ocean plastics take much longer to break down and the porous structures that form in plastics that have been exposed to ocean elements provide the perfect place for POPs to latch on and protect themselves from degrading in the open ocean.


Plastics “Bleeding” Chemicals


Hitchhiking toxins aren’t the only way dangerous chemicals are lingering in our ocean. A study conducted in 2009 found that while plastics in daily use “are generally assumed to be quite stable…plastic in the ocean actually decomposes as it is exposed to the rain and sun and other environmental conditions, giving rise to yet another source of global contamination that will continue into the future.”


Now, these plastics don’t completely decompose in the way organic material does. But they do begin to “bleed” their chemical components, releasing harmful toxins into the oceans.


Another study conducted in 2018 estimated that “the global quantity of plastic in the ocean will nearly double to 250 million tonnes by 2025, which likely also represents a pollutant load of millions of tonnes of chemical additives.”


So, with ocean plastics providing safe harbor to existing toxic chemicals, while also contributing more to the oceans as they break down, the masses of floating plastic waste in our oceans aren’t just changing our oceans cosmetically, they’re changing them chemically. And researchers still aren’t sure what the consequences of exponentially increased POPs in our oceans will be, but there is largely a consensus that humans will be facing major health consequences if and when we get there.


You can help stop plastic pollution in our oceans by purchasing products from companies dedicated to producing plastic-free, sustainable products. RIO not only helps you stock up on sustainable goods, but is also dedicated to using the proceeds to rid our oceans of plastic once and for all.