plastic ocean

When it was first invented, plastic was a modern miracle – strong, durable and cheap. But do we really need take-away containers that will last 10,000 years?


When it doesn't end up in the bin, what happens to the rest of the plastic that we forget to recycle? Those plastic bags floating in the wind, or that Havaiana lost on the beach? Or even the tiny plastic beads in your exfoliator, once it washes down the drain? Plastic doesn’t just disappear; it can take tens of thousands of years for the polymer to completely break down. When not recycled, plastic debris makes its way down the drain or into waterways and onto beaches, to be carried way out into the open ocean. Powerful currents drag litter towards whirlpool-like gyres, where the debris accumulates, swirling around, trapped in a plastic soup. 

One of the biggest of these gyres is in the North Atlantic, the Sargasso Sea. The journey from the US East Coast across surface currents takes about six weeks, and along the way, larger pieces of plastic are exposed to an abundance of UV rays in the form of heat and sunlight, breaking the pieces down into microplastics – tiny fragments smaller than five millimetres. The United Nations Environment Program estimates on average, worldwide, every square kilometre of seawater contains around 13,000 pieces of microplastic debris.

While floating plastic bags and abandoned fishing nets pose a hazard to marine wildlife by entangling or suffocating them, marine microplastics are so abundant across the globe that they are potentially a far greater threat, despite their tiny size.

The hydrophobic plastic particles are a magnet for heavy metals and toxins, which are often oily in nature. When birds, fish, turtles and filter feeding whales mistake these toxin- coated microplastics for food, they are exposed to high concentrations of these chemicals, with potentially fatal consequences.

However, the microplastic problem gets proverbially bigger, and literally even smaller. Not only magnets for toxins, microplastic surfaces provide the ideal habitat for thousands of types of bacteria, invertebrates and viruses. As the plastic degrades, it becomes pockmarked and the range of surface textures provides ideal habitats for many species. Microplastics provide tiny floating life rafts to whole ecosystems, enabling organisms that previously were unable to survive in marine conditions to reproduce and move all around the globe.

The ‘biofilms’ these organisms form on the plastic’s surface allow toxins to attach to the plastic’s surface, some of which can be carcinogenic to humans and other organisms. The bacteria themselves can also be pathogenic, with cholera and E. coli amongst the 1000 different types of bacteria identified in microplastic ecosystems.

The effect of these noxious inhabitants further up the food chain on apex predators, like sharks – and people – is yet to be determined. According to Kay Critchell, a marine science PhD candidate at James Cook University, “humans are at the top of the marine food chain; eventually the fish we are eating are going to be contaminated with plastics and the chemicals that go with it”.

However, finding a viable solution is near impossible. Critchell says the unprecedented ecological implications and danger to public health are permanent consequences of our “disposable lifestyle”. We are all responsible for daily use of plastic materials, and more often than not their incorrect disposal. From 2011 to 2012, only 20 per cent of plastic was recycled in Australia, most of which was from single use packaging.

Critchell uses oceanographic modeling to predict areas of accumulation of marine debris in the Great Barrier Reef region. When it comes to cleaning up what is already out there, she says beach clean ups can be really efficient. Initiatives such as Take 3 encourage beach-goers to find three pieces of rubbish from the sand or surf and dispose of them correctly. Better sewage and storm water filtration systems and more efficient recycling could also help lessen negative impacts.

The oceans themselves are international and the question of responsibility is ambiguous, so coordinating large-scale clean up efforts between countries is immensely complex. A significant amount of marine debris comes directly from ships dumping waste overboard. While there is legislation to stop this, efficiently policing international waters requires diligence and better cooperation between governments. With so much rubbish out there, many countries are at a loss to even know where to start. Nets to scoop up plastic can trap wildlife, and many developing nations don’t have the facilities on land to deal with the waste brought back to shore.

More research is needed on effective waste management, says Critchell, but she still recommends starting on an individual level. “Every dollar you spend is a vote for how you want the world to be. If you actively choose the items with the least packaging, then that will filter though. Avoiding single use plastics makes a real difference. You can use reusable containers instead of cling wrap, carry a water bottle instead of buying bottled water, use a reusable coffee cup, and take reusable bags to the supermarket. All these things make a difference. If there is less waste produced, there is less waste in the ocean.” LL.


This article originally appeared in Issue 9 of The Bull 2015.