An ocean of plastic

The fate of Malaysia Airlines Flight MH370 has been shrouded in mystery ever since it left Kuala Lumpur for Beijing in the early morning hours of March 8 with 239 people on board. While the Boeing 777 is believed to have crashed in the southern Indian Ocean, search efforts have repeatedly been hampered by objects spotted by radar, ships and airplanes that have turned out to be garbage, leading to growing frustration among the victims' relatives and search crews.

But the false sightings have put the spotlight on the wider garbage problem affecting the world's oceans. In a DW interview to mark World Environment Day on June 5, Dr. Wendy Watson-Wright, Executive Secretary of UNESCO's Intergovernmental Oceanographic Commission (IOC) talks about the consequences of these vast quantities of trash bobbing around the ocean, both for humans and wildlife, and points to what she regards as the only way to solve the problem.

DW: How serious is the marine garbage problem in the Pacific Ocean?

Dr. Wendy Watson-Wright: The problem is very serious, but not quite as graphically enticing as most commentators out there would have us think. The name "Pacific Garbage Patch" is slightly misleading, as it leads you to think of a large and continuous patch of litter – a literal island of trash that one might be able to see on aerial photos or even from space.

The truth is less appealing, unfortunately. I say unfortunately not because an "island of trash" would be a better alternative to the "soup" of small pieces of floating plastic that comprises most of the "garbage patch," but because a solid, floating island of visible trash might be more straightforward to clean.

The truth is that the debris that accumulates in the ocean is continuously mixed by wind and wave action and widely dispersed over huge surface areas and throughout the top portion of the water column. It is possible to sail through the "garbage patch" area and see very little or no debris on the water's surface.

It is also difficult to estimate the size of these "patches" because the borders and content depend on ocean currents and winds. In the end, we are left with few certainties in regards to the size and mass of these concentrations of debris, but one thing is for sure: large portions of man-made debris in the ocean can never be a harbinger of good news.

To your knowledge, how has the large amount of garbage in the ocean affected the search for missing Malaysian airplane MH370?

The large amount of garbage has surely generated some false hopes as the satellites keep spotting large, but unrelated pieces of debris, fishing equipment, and other flotsam. If anything positive can be said to have come out of this terrible incident, let us hope that it will be a renewed attention on the part of the general public, the press, and decision-makers to the awful amounts of man-made debris dumped everyday in the ocean.

What is the most abundant type of garbage found in the ocean?

One of the main types of marine debris that you hear about today is plastic marine debris. In many places, it is the main type of debris that you will see as you walk along a beach, though perhaps not underwater. As society has developed new uses for plastics, the variety and quantity of plastic items found in the marine environment has increased substantially.

From common household materials to industrial products, to lost or abandoned fishing gear, all of these plastic materials increasingly find their way to the ocean and contribute to a problem that will catch up with humankind sooner than later.

The other reason for why plastic is the most abundant type of garbage in the ocean has to do with its degradation rate. Plastics do degrade in the ocean, but there are many different types, each with a specific chemical composition and degradation rate. Research tells us that the most common types of plastics have such slow degradation rates that they never fully "go away," and instead break down into ever-smaller pieces.

To what extent are other oceans also facing a garbage problem?

The "patches" of the Great Pacific Garbage Patch are not the only open ocean areas where marine debris is concentrated. Another important area is the North Pacific, in the Subtropical Convergence Zone (STCZ). This area, located north of the Hawaiian archipelago, has a high abundance of marine life, but is also known for marine debris concentration. That said, whether the garbage is in the Pacific or the Atlantic, it matters very little. To a greater or lesser extent, the problem affects the ocean in its entirety.

What impact is this huge amount of garbage having on marine biology?

The impacts are many, and quite severe. Abandoned nets, plastic tarps, fishing gear and other debris can smother and crush sensitive ecosystems and their bottom-dwelling species. Fishing line, nets, rope and other debris can entangle and drown many wildlife species. Animals can also ingest debris, which can lead to starvation and/or choking.

Studies have shown that fish and other marine life do eat plastic, suffering from irritation, damage to the digestive system, and/or malnutrition or starvation as a result. Medical and personal hygiene debris are particularly threatening for marine biology, as they may contain harmful bacteria that will propagate in waterways.

How big a threat does the growing level of pollution in the ocean pose to people?

In terms of direct impacts, one can quickly think of the danger that syringes and broken glass pose to barefooted beachgoers. Grocery and trash bags, fishing line, nets, rope and other debris provide examples of threats to human life, as they can wrap around boat propellers and clog seawater intakes, causing costly damage and potentially turning into a safety hazard.

It is when speaking about the indirect impacts of marine pollution that we should be most alarmed, however. Plastic debris accumulates pollutants such as PCBs (polychlorinated biphenyls) up to 100,000 to 1,000,000 times the levels found in seawater. Banned in the US for some time now, PCBs could potentially make their way back into human life cycles everywhere via marine animals that have ingested plastic with high PCB levels. The negative impact on humans from consuming these infected animals is high and could result in severe poisoning.

What can be done to solve the problem?

The answer to this question is not as simple as one would think, as we can't even talk about cleaning it all up. It is not cost-effective to skim the surface of the entire ocean, and even a cleanup focusing on "garbage patches" would be challenging and financially onerous.

Taking into consideration that debris concentration in "garbage patches" moves and changes constantly, that these are incredibly large areas, and waste particles are not distributed evenly within the "patches," the whole question adds up to a huge challenge. That is without mentioning the fact that these areas of marine debris concentration may also be repositories for certain types of marine life, making a simple "skimming job" risky for marine biodiversity in those areas.

The only solution is to implement wise waste-disposal policies on land to make sure that plastic and other harmful materials go through appropriate waste management schemes and stay far clear of the ocean.

This may seem like a large task for governments at the local and national levels, but every citizen can do his or her part by responsibly disposing of trash, participating in local cleanups, reducing your waste and rethinking overall consumption patterns. Remember the 3 R's: Reduce, Reuse, Recycle!

Dr. Wendy Watson-Wright is Executive Secretary of UNESCO's Intergovernmental Oceanographic Commission (IOC) in Paris. The United Nations body for ocean science, ocean observatories, ocean data and information exchange, and ocean services such as Tsunami warning systems.

The interview was conducted by Gabriel Domínguez.