This is Genevieve Johnson speaking to you from the Odyssey in the Canary Islands.
When I reflect on our time researching at sea over the past five years, two unrelated things stand out – sperm whales and plastics.
We are not always assured of finding sperm whales. However, even in the most remote regions of the ocean, plastics are guaranteed. Unfortunately, the relationship between plastics and all marine life is far more intricate than most of us could possibly imagine.
The numerous benefits of modern society’s productivity make almost all of us utterly addicted to plastic products. Most of the products we use on a daily basis include, or are contained in plastic. We drink out of them, eat off them, carry food and clothing in them, sit on them and drive in them. Plastics are durable, lightweight and can be made into virtually anything. It is these very practical and useful properties of plastics that make them so harmful when they make their way into the oceans. Unfortunately, most of us give little thought to where plastics come from or where they end up after they have served our brief purpose.
The vastness of the ocean is incomprehensible to those who have never spent any time at sea. Yet, as we gaze out over the horizon from onboard Odyssey over what most of us imagine is a pristine seascape, we are continually confronted with a sea of plastic.
Historically, humans have always tossed waste into the ocean but marine organisms broke it down in a relatively short time. Unfortunately, our quest for convenient packaging over the past 50 years or so, created a class of plastic products that are immune to even the most rapacious bacteria.
Despite the era of recycling, only 3.5% of plastics are recycled in any way throughout the world. Today, plastic debris causes considerable, widespread mortality of marine wildlife, including mammals, birds, turtles and fish through entanglement in monofilament plastic fishing gear and ingestion. Turtles mistake plastic bags for jellyfish and other prey. Seabirds, particularly Albatross, mistake plastics floating at the surface for food and ingest them while foraging. Three hundred thousand cetaceans drown annually in fishing gear, while necropsy records of several stranded cetaceans, including large whales and particularly dolphins, reveal the ingestion of plastic debris.
The problem with plastics is they do not biodegrade. When something biodegrades, naturally occurring organisms break down natural materials into their simple chemical components. For example, when paper breaks down it becomes carbon dioxide and water. However, plastic is a synthetic material and never biodegrades. Instead it undergoes a process called ‘photodegredation’, whereby sunlight breaks it down into smaller and smaller pieces over very long periods of time. A disposable diaper takes an estimated 500 years to break down while plastic 6-pack rings for cans take 400 years and a plastic water bottle can take up to 450 years to degrade. However, this does not mean they will disappear, all remain as plastic polymers and eventually yield individual molecules of plastic too tough for any organism to digest.
In 2001, the Algalita Marine Research Foundation based in Long Beach California led by Captain Charles Moore, conducted a survey thousands of miles out to sea in a remote region of the Pacific Ocean known as the North Pacific subtropical gyre in an effort to assess the extent of the problem of plastic pollution in the ocean. Gyres are areas where oceanographic convergences and eddies cause debris fragments to accumulate naturally. What the researchers discovered was both shocking and outrageous, a floating mass of plastic junk stretching across an area of ocean the size of Texas. Rivers of soda and water bottles, spray can tops, candy wrappers, cigarette lighters, shopping bags, polypropylene fishing nets, buoys and unidentifiable, miscellaneous fragments collected in a huge rotating mass of plastic pollution.
In addition to large obvious pieces of plastic, the results of the survey revealed minute plastic fragments mixed with tiny sea creatures. The published results from the survey reveal a sea of plastic soup comprising “six pounds of plastic floating in the gyre for every pound of naturally occurring zooplankton.” Charles Moore now believes “plastic debris is the most common surface feature of the world’s oceans.”
Until now, no studies were conducted on filter-feeding organisms such as jellies, whose feeding mechanisms do not permit them to distinguish between tiny fragments of plastic debris and plankton, and no studies to assess potential effects on these filter-feeders. It is now known that plastic fragments heavily impact these creatures. When broken into smaller pieces, these tiny plastic fragments accumulate non-water soluble toxicants such as PCB’s, and pesticides such as DDT. Plastic polymers, or tiny plastic resin pellets act as sponges for these chemicals and other persistent organic pollutants, concentrating such poisons up to one million times higher than their concentration in the water as free floating substances.
The implications and scope of the problem is astounding considering about 250 billion pounds of plastic pellets are produced annually worldwide for use in the manufacture of various plastic products. When these products break down into fragments and disperse throughout the oceans, they concentrate and transport toxicants. In the North Pacific oceanic gyre, Moore and his team witnessed filter feeding jellies or salps with brightly colored plastic fragments in their stomachs. Fish consumed by larger and larger predators in turn eat these tiny organisms, all the while the toxicants continue to climb and concentrate up the food chain. In many cases, this chemical pathway leads directly to human beings. Many of these chemicals are ‘hormone mimics’ and ‘endocrine disruptors’ and are released into the body when plastic is ingested. The effects of hormone disruption on humans can range from birth defects to cancers.
The facts are daunting and the future looks grim. Moore and his colleagues currently predict a 10-fold increase in plastic in the ocean by 2010 bringing the ratio of 60 pounds of surface plastic to every one pound of zooplankton in the North Pacific gyre.
In the meantime, it is up to all of us to be aware that we share one fragile earth, sustained by one ocean system. We can all contribute to its demise, but more importantly we are all responsible for the conservation of our marine environment and the amazing life it supports. We do not need to make sacrifices in our lives, only minor modifications. We can help minimize the impact by being responsible about the amount of plastic products we consume. Unfortunately labeled recycling bins are not always reliable; if possible reduce the amount of plastic products you purchase by searching for alternative materials and reuse plastics where possible. We can all make a difference.
