Seventy-one percent of the surface of our home planet, Earth, is covered by water. This water creates our global ocean systems and is essential for life as we know it to thrive. More than a billion people, predominantly from developing nations, rely on seafood as a primary source of animal protein and more than fifty percent of the human population rely on fish for fifteen percent of animal protein.
The global ocean system is made up of five oceans; the Atlantic, Pacific, Indian, Arctic and the Southern (Antarctic) and thirteen Seas; Mediterranean, Caribbean, South China, Bering, Gulf of Mexico, Okhotsk, East China, Hudson Bay, Japan, Andaman, North, Red and the Baltic Sea.
Ocean currents connect and circulate water around the global ocean system and form what are known as Gyres. A gyre is a vortex created by rotating ocean currents, there are five main gyres in our global ocean system. (see image below) The Indian Ocean Gyre, North Atlantic Gyre, North Pacific Gyre, South Atlantic Gyre, and the South Pacific Gyre.
As water is moved around our planet through ocean current systems, also transported are: chemicals such as salts, oxygen, carbon dioxide; plankton; fish; heat; and trash. Rubbish which falls from ships, that is carried down storm water, or which is blown by wind, ends up in our ocean and is transported through ocean currents collecting in gyres.
Perhaps one of the best documented gyres is the North Pacific Gyre, better known as “The Garbage Patch“, which consists of three main locations within the gyre where microplastics have been found to collect.
How Does it Get There and What Are The Impacts
Plastics enter the ocean when they fall from ships, are carelessly discarded, are blown by wind into waterways, or escape from water treatment plants. The waste we see on the side of the road or in fields can make its way into storm-water systems and pass out to the sea.
Plastic never breaks down completely, even after breaking down to the smallest particles (microplastics) it remains plastic. In the ocean these very small plastic particles are eaten by sea life at the bottom of the food chain, such as Sandhoppers. These creatures are eaten by larger ones, and so on until finally ending up as the fish on our plate. Researchers have also found corals to be ingesting tiny plastic particles, which could prove to be fatal should they fill the digestive system. Coral reefs provide shelter for twenty five percent of marine species while only occupying two percent of the ocean. Over 500 million people rely on coral reefs for both food and resources, most of which live in the poorest nations on our planet.
Toxins in the Plastic Soup
Pesticides contaminate land and water when it escapes from production sites and storage tanks, when it runs off from fields, when it is discarded, when it is sprayed aerially, and when it is sprayed into water to kill algae. Fertilizer runoff from farms and lawns is a huge problem for coastal areas. The extra nutrients cause eutrophication – flourishing of algal blooms that deplete the water’s dissolved oxygen and suffocate other marine life. Eutrophication has created enormous dead zones in several parts of the world, including the Gulf of Mexico and the Baltic Sea. Oil spills cause huge damage to the marine environment but in fact are responsible for only around 12% of the oil entering the seas each year. According to a study by the US National Research Council, 36% comes down drains and rivers as waste and runoff from cities and industry.
Among the many chemical and biological toxins found floating in the ocean, scientists have identified a number of particularly harmful compounds called “persistent organic pollutants” or P.O.P.’s, exposure to them can cause death and illnesses including disruption of the endocrine, reproductive, and immune systems. After a heavy rain, coastal rivers and streams carry many different pollutants to the sea. As rainwater washes into gutters and storm drains, it carries with it all that we have carelessly left behind.
Most plastics in use today, excluding the few plant-based alternatives slowly reaching the market, are made of petroleum and as a result they float like oil on or near the surface of the ocean. When exposed to sunlight over prolonged periods of time, these plastics break up (photodegrade) into smaller and smaller particles until all that remains is a fine plastic dust. Unfortunately, this seemingly harmless plastic dust retains all its chemical components and will never biodegrade. In fact, unless it was incinerated, all of the plastic ever made remains in the environment to this day.
Researchers, such as Dr. Hideshige Takada, are now learning that floating plastic particles attract P.O.P.’s (Persistent Organic Pollutants) from surrounding sea water like a magnet. As these plastic particles make their way through the oceanic currents, they accumulate P.O.P.’s and transport them around the globe. Many of these pollutants are known carcinogens and are potentially harmful to animals when ingested. Studies have also shown that these plastic particles contain P.O.P. levels up to a million times higher than in surrounding sea water.
As plastic builds up in the food chain carrying with it increasing amounts of toxins, there is the potential that it could reach food organisms that are harvested by humans. We are the apex predator of the sea and when we consume fish and seafood, we consume everything that they have consumed. There is growing evidence that some of the toxins associated with plastic particles in the gyre are responsible for an increase in health problems in humans such as endocrine cancers and brain damage, as well as reproductive and cardiovascular damage.
It stands to reason that if plastics are found in the North Pacific Gyre in all probability they are present in every Gyre around our planet. Scientists announced the existence of a garbage patch in the Indian Ocean, another in the North Atlantic Ocean, and in February of 2015 National Geographic reported that plastics are turning up everywhere from the deep sea to Arctic ice.
It is difficult to determine what the impacts of plastics in the oceans could be. What we do know is that plastics sorb petroleum based toxins in the surrounding sea water, that corals and other marine creatures are mistaking microplastics for food and ingesting them resulting in toxins building up in the food chain. If these plastics prove fatal to corals we could destroy the habitats of twenty five percent of marine species, if toxicity levels reach levels high enough to kill fish we will destroy already under pressure fisheries.
Treatment for a Symptom
Boyan Slat has come up with an interesting way to try and tackle this symptom. He proposes the use of a series of booms secured to the seabed that collect plastics as they travel with the ocean currents.
This is a fantastic idea and is something we should get behind and support, but we also need to understand the cause of the symptom, face facts and deal with it.
We could turn to biodegradable plant based plastics, such as hemp plastic, implement alternative farming techniques that do not employ the use of pesticides such as vertical farming and perhaps more importantly we could address our rapacious appetite for stuff. As a society we produce and consume at an obscene rate, very little thought if any at all is given to how and where these products are made, or what social value many of these products have. Sadly most of what we consume has near zero social value, it is simply materialistic garbage we do not need at all, which by default will end up being thrown away almost immediately along with its associated packaging. This means it is all too likely that it will end up in our oceans and possibly in our food. It is not enough to clean up an existing mess, we also need to stop making it.
Shirts and Shoes Required by Toxic Wasted CC 3.0
Clouds Over the Atlantic Ocean by CC BY-SA 3.0
EARTH-OVER-AFRICA-halfnight by Jason Harwell CC BY-SA 3.0
Fish soup MOs810 by MOs810 CC BY-SA 4.0