Every minute, the equivalent of a truckload of plastic enters the sea. Since 2004, humans have produced more plastic than we did in the previous 50 years combined. As the global population rises, our need for cheap and sturdy materials rises with it. The problem with plastics is that they are too sturdy. Every piece of plastic ever produced still exists somewhere in the world. Once the plastic has finally disintegrated, that is by no means the end of the problem. Plastics in the ocean break down into tiny particles known as microplastics. Such particles are found throughout marine ecosystems; from the stomachs of fish, to the stomachs of the seabirds who eat them.
Microplastics are not only dangerous, but also extremely difficult to clean up since they are spread out by currents all across the sea. In order to be classified as a microplastic, a piece of plastic debris must be roughly the size of your little fingernail or smaller. There are over 320 million cubic miles of water in the world’s oceans. For a sense of scale, you could fit roughly 320 million cars into a single cubic mile. Scientists have estimated that there are up to 50 trillion pieces of microplastics in the oceans. Given these figures, to say that removing microplastics from the ocean is no easy task would be the understatement of the century.
The reason that high levels of plastic in the ocean are problematic is that plastics have serious detrimental effects on the health of almost all ocean life. Over 800 species of animals have so far been shown to be negatively affected by plastic pollution. Considering that number was closer to 600 in 2012, it is safe to assume that the figure will continue to rise dramatically in the coming years. What’s more, almost 20% of the animals shown to be affected by plastic pollution are already classified as endangered due to human activity. There are two major ways in which plastics can harm or kill marine life. First, they can be ingested. When marine animals ingest plastic, the pieces can remain in their stomachs for the rest of their lives. As the amount of plastic increases, the space remaining in the stomach decreases, causing the animal to starve. In addition to this, most plastics are toxic to animal life, causing conditions like cancer and birth defects. Second, marine animals can become entangled in the plastic. If this happens at a young age, the plastic can restrict the growth of the animal, causing them to become severely deformed. This is seen most often in sea turtles. The worst offenders when it comes to entanglement are pieces of discarded fishing gear.
The phenomenon of marine life being caught by gear that has been abandoned by fishermen is known as ‘ghost fishing‘. Nets, hooks, lines, and cages continue to catch and kill fish long after the fishermen have stopped using them. Roughly 30% of all fish that are caught by humans are caught in ghost fishing gear. When you consider the sheer scale of human fishing, this percentage is astonishingly high. Leaving plastic fishing gear in the ocean, plastic or otherwise, is both short-sighted and despicable. Fishing gear is specially designed to kill as much marine life as it can. When it is under the control of a fisherman, protected marine life like whales and sea turtles can be avoided or released. Even so, fishing of any sort is devastating to endangered species. When the gear is abandoned, however, there is no targeting of species, leading to indiscriminate destruction of marine habitats.
There have been a lot of stories in the news recently about how companies like McDonald’s and Starbucks are ditching plastic straws. While this is a step in the right direction, straws only account for roughly 1% of the plastic debris in the ocean. In order to make a real difference, the companies would have to stop using plastic straws, containers, bags, cups, lids and everything else. This is a perfect example of what’s known as corporate ‘greenwashing’. If the public perception of a company is that they are trying their best to reduce the environmental damage they are causing, less people will boycott the company’s products, leading to higher revenue. Because of this, companies make the calculated decision to sacrifice a small portion of their profits in order to further their public personas as stewards of the environment. This is not to say that small steps forward like those taken by McDonald’s and the like are not helpful. Carlsberg have recently announced that they are ditching the plastic rings connecting cans in favour of glue dots. This is a positive development, since these connector rings have been shown to strangle and stunt the development of marine life and seabirds.
Plastic is not distributed evenly throughout the ocean. There are 5 major places, known as gyres, where currents have forced plastics to accumulate into huge expanses of debris. The largest of these gyres is called the great pacific garbage patch (GPGP) and contains about 2 trillion pieces of plastic. That’s 250 pieces of plastic for every human on earth in just one place. The GPGP is around the size of Texas and weighs about the same as 500 jumbo jets. The accumulation of plastic in gyres like the GPGP makes it somewhat easier to clean up oceanic plastic, but it is still a monumental challenge.
When he was just 17, Dutch aerospace engineering student Boyan Slat devised a huge U-shaped machine to clean up the GPGP that he believes could clear 50% of the plastic in just 5 years. The device uses ocean currents to move with the plastic, but since it is largely above the surface, it moves faster than the plastic, gathering it as it goes. It was deployed in the gyre in September of last year but was immediately faced with a slew of setbacks. The device was not travelling fast enough, allowing some of the plastic to escape, then a 60-foot section of the machine broke off, meaning that it had to be brought back to shore for repairs. Another issue with the device is that it cannot collect microplastics. However, it is important to gather up as many of the large pieces of plastic as we can now, since they will become microplastics in the future which will be much more difficult to clean up. We are in full damage control mode.
Despite valiant attempts to reduce our plastic consumption and remove the plastic we have already dumped in the ocean, it is highly unlikely that this problem will be solved any time soon. If anything, it will get much much worse. Humans have a history of showing up at a new location and decimating the native wildlife populations. When we first arrived in Australia, huge animals roamed the land. These included a 2-and-a-half-ton wombat, a flightless bird twice the size of an ostrich, and a predatory marsupial the size of a tiger. Within a few thousand years of humans showing up, 23 of the 24 animals that weighed over 50 kilograms had become extinct. We have spread all over the planet now, leaving only a few havens in which animals may thrive. The new frontier of animal extinction is marine life. Plastic pollution, overfishing and ghost fishing have devastated marine life and seabirds already, and the rate of destruction is only going to increase. All we can hope for is that people wake up to the genocide we are committing under the waves in time to save at least some of the majestic creatures who call the sea their home.