Contamination of Our Oceans

There is no more egregious demonstration of the damage we have done to our world in the Anthropocene Era than the conditions of our oceans. They cover about 70% of the earth’s surface – about 140 million square miles. Yet, despite that enormous area, billions of pounds of plastic can be found in convergences that make up about 40% of world’s ocean surfaces. If you multiply those two numbers, then 28% of the world’s surface is covered in plastic. 

The Center for Biological Diversity estimates that in the first decade of this century, we made more plastic than all the plastic in history up to the year 2000. And every year, billions of pounds of more plastic end up in the world's oceans. Studies estimate there are now 15–51 trillion pieces of plastic in the world's oceans — from the equator to the poles, from Arctic ice sheets to the sea floor. Not one square mile of surface ocean anywhere on earth is free of plastic pollution. Unfortunately, plastic is so durable that the EPA reports “every bit of plastic ever made still exists.” All five of the Earth's major ocean gyres are inundated with plastic pollution. The largest one has been dubbed the Great Pacific Garbage Patch.

This vortex of waste in the central Pacific Ocean has been estimated from 270,000 sq. miles to almost 6 million sq. miles. Even if we use only the smaller estimate, it is an enormous area and something of which we all should be ashamed. It has been estimated that 5-13 million metric tons of plastics enter the oceans annually. If we consider only the Pacific Garbage Patch, more than 1.8. trillion pieces of plastic, with a weight of 80,000 tons have accumulated thus far. 

This patch is not visible by satellite imagery or by persons in the immediate area since it is a widely dispersed suspension of tiny bits of plastic, some microscopic, that are known as microplastics. Paradoxically, the best-known method for degrading plastics is exposure to UV light coupled with mechanical disruption, such as constant wind and wave motion or grinding on rocks. This breaks down larger pieces of plastic into microplastics or even nanoplastics. The former are less than 5 mm and the latter are less than 0.1 micrometers. Some the plastic is more than 50 years old and includes essentially any type of plastic waste you can imagine.  This patch appears to have been accumulating about 10-fold per decade since 1945. 

Similar patches exist in the North Atlantic and Indian Oceans.

This problem has been extensively studied by the Scripps Institution of Oceanography, the National Ocean Service, and the United Nations. The UN Ocean Conference estimated that by 2050, the oceans might contain more weight in plastics than fish if the process is not curtailed or reversed. 

Plastic attracts seabirds and fish. Larger and, especially, smaller pieces of plastic are ingested and thereby enter the food chain. The small sizes of these pieces of plastic are a major concern since they have entered into our food chain and, ultimately, into our own intestinal tracts. They blow in the wind and have been found in high mountain areas where people have not travelled recently.  We have created a ubiquitous health, sanitation, and aesthetic problem. 

 
According to an extensively referenced article in Wikipedia, of the 1.5 million albatrosses on Midway Island, nearly all have plastic in their gastrointestinal tracts. Some of this is unwittingly fed to their chicks. Twenty tons of plastic debris washes up on Midway every year, with five tons ending in the bellies of albatross chicks. Dead seabirds of many types are found with stomachs full of plastic. This pollution affects about 700 marine species, to include sea turtles, seals, sea lions, seabirds, fish, and whales and dolphins. 

Fish in the North Pacific ingest 12,000 – 24,000 tons of plastic annually. Sea turtles take in plastic, thinking it is food and choke, sustain internal injury, or die by starvation. About half the sea turtles worldwide have ingested plastic. 

The Ocean Conservancy estimates that every year, 8 million metric tons of plastics enter our ocean on top of the estimated 150 million metric tons that currently circulate our marine environments. This includes plastic bags or plastic straws finding their ways into gutters and large amounts of mismanaged plastic waste from rapidly growing economies, that is dumped into rivers and sewers which ultimately empty into the oceans.  That’s like dumping one New York City garbage truck full of plastic into the ocean every minute of every day for an entire year! 

The problem in the oceans is out of control and, when considered along with the environmental damage we are doing with petroleum mining on land, clearly demonstrates that the Anthropocene Era is perhaps the worst tragedy to occur on earth since the asteroid impact 66 million years ago that eliminated the dinosaurs and 95% of life on earth in one enormous cataclysm.

 Can we correct this or is it too late to do so? We will address this in the third and final blog in this series on plastics.