Out in the Pacific lies one of our planets largest islands. There are no golden beaches of sand, this island is made almost entirely from what we throw away. It is known as the “Great Pacific Garbage Patch.” Its size is estimated to be around 1.6 million square kilometres. That’s an area larger than Mongolia! Worse still, it’s growing every day.
This is one of several oceanic garbage patches that accumulate in our seas. Others are in the Pacific, Atlantic, and Indian Ocean. But how do they form? And what effect do they have on the planet?
How do Gyre’s form?
The main source that creates these areas of waste is quite simply – us! Globally, we dump 2.12 billion tons of waste each year. Less than 20% of it is recycled or composted.
Plastic is the biggest offender, it accounts for 80% of marine debris. While figures vary, it is estimated 12-14 million tonnes end up in the oceans each year. Some is from direct dumping but the majority comes indirectly from land based sources. So whether we are living right on the coast or in the middle of a continent, we are all contributing to the problem.
While over 90% of this waste ends up on the sea floor, recent estimates suggest 171 trillion pieces of plastic are currently floating in the upper waters of our seas. This is around 2 million tonnes. That’s roughly the weight of 2 million Walrus’s, or 200 Eiffel Towers!
This floating waste is gathered into large patches by oceanic currents known as Gyre’s. These circular moving currents found in our oceans, gather up and herd plastic and other waste into the stiller waters at their centre. There are five large oceanic gyres, two in the Pacific, two in the Atlantic, and one in the Indian Ocean, all of which have their own floating garbage patches.
The density of these patches vary in places. Floating on the surface common finds include plastic bottles, bags, fishing gear, and food packaging. However, calling them islands, or patches, is perhaps misleading. As intermixed in the sub-surface water is a ‘peppery soup’ of microplastics that can extend deep into the water column. This soup-like consistency worsens over time as the larger items break down into smaller and smaller pieces. So whilst it may not seem so bad in areas along the surface, below the waves, it can be a very different story.
A “Great” big problem
In our previous article; Bottom of the Food Chain – But Priceless! we mentioned the direct effect these patches have on marine life and it’s not good news.
The accumulation of so much plastic can be a physical barriers to the natural processes that occur in our oceans. This includes, reducing the mixing of surface and deep waters, which in turn decreases the oceans effectiveness in absorbing CO2 from the atmosphere. It also reduces the light entering the ocean, disrupting the effectiveness of marine plants like phytoplankton to photosynthesize. This fundamentally effects the very basis of the marine food-web, and lowers the effectiveness of phytoplankton’s ability to absorb carbon to regulate our planet’s atmosphere.
As plastic continues to flow into our seas at an alarming rate, these patches will become larger yet, further magnifying its effects. Worryingly, some of these oceanic garbage patches are so prominent now they have become habitats of their own. A study in the Great Pacific Garbage Patch highlighted 90% of the sample debris had associated marine life. Adverse effects of this include, invasive introduction of coastal species to new environments.
Microplastics are commonly mistaken for food by marine life, including fish, birds, turtles, and marine mammals. These non-digestible items when consumed, cause gastro-intestinal blockages, painfully killing the animals. Further problems occur when plastic begins to “break down” in our seas. They release toxic chemicals directly into the surrounding water. It can also alter the pH levels of our seas.
Finally, these oceanic garbage patches also create economic problems for those who make a living from the seas. Floating debris can disrupt marine navigation, by fouling the propulsion systems of ships. Similarly it can entangle and disrupt fishing equipment such as, nets and lines.
Solutions for our seas?
The sheer scale of the problem may seem hopeless. As part of the human race, we are the source of these garbage patches but we are also the solution.
Dedicated groups and individuals removing litter from the sea and our environment is one solution, as are those helping to stop it entering the sea in the first place. Research and technology too is also finding new ways to help clear this marine debris en-masse.
Removing marine garbage once it has entered the ocean is expensive. The best way we can help as individuals, is to limit plastic and other waste altogether. Embracing reusables, like cups, bottles, straws and bags is a great start. We can also make informed decisions as consumers, by buying fewer items with plastic packaging. We can also make dispose of our waste responsibly, recycling wherever possible and ensuring it is stored in secure bins so it does not escape into the environment.
By acting sustainably, we can help reduce this problem right at the source, but it will take all of us to do it. So most of all, we must become activists on behalf of our planet by supporting policies and regulations that aim to reduce plastic pollution such as, plastic bag bans, extended producer responsibility and recycling programs like our BinForGreenSeas. We can also use social media to hold organisations to account and spread the word about these policies and issues, for instance, by making and sharing your own GreenSeas pledge!