Marine Debris

In 1997, Captain Charles Moore, founder of the Algalita Marine Research Foundation (AMRF), was sailing his 50-foot racing catamaran, the ORV Alguita, back to California from Hawaii and decided on a lark to cut through the center of the North Pacific Subtropical Gyre. The Gyre is an enormous vortex of currents revolving around a continuous high-pressure zone. Boats typically avoid it since it’s essentially one big windless death trap, so when Moore motored through it, it was just him, his crew, and an endless field of ….. garbage.

In the eastern portion of the Gyre, Moore encountered a substantial amount of trash, mostly plastic, scattered across the area. Now commonly referred to as the Great Pacific Garbage Patch, it is a vast plastic soup containing everything from large abandoned fishing nets to plastic bottles, bottle caps, toothbrushes, containers, boxes, to miniscule particles of plastic (polymers) that have either been reduced from larger pieces by wave action or photodegradation. Since then, Captain Moore has made numerous research voyages to the Gyre, resulting in a body of authoritative research publications, data and educational programs, while expanding his research to include all five major gyres worldwide.

Environmental Impacts of Marine Debris and Plastic Pollution

What is exactly the global environmental problem of marine debris and plastic pollution we’re dealing with ? In two reports of the United Nations Environment Programme (UNEP) dedicated to this topic, marine debris (or marine litter as this term is used) are defined as ‘any persistent, manufactured or processed solid material discarded, disposed of or abandoned in the marine and coastal environment’. This definition is also used in a 2010 report of the Marine Strategy Framework Directive Taskgroup (EU) on marine litter. As the latter gives a more refined clarification on the subject, it excludes ‘ semi-solid remains of for example mineral and vegetable oils, paraffin and chemicals that sometimes litter sea and shores’.

Of all marine debris, plastic accounts for more than 80 %. But where does it all come from ? Global estimations account land-based sources for some 4/5 of marine debris, while the remaining part originates from marine resources, e.g. vessel source pollution. Marine debris can be encountered in the surface, in the water column, and even on the ocean floor. In some places, marine debris occurs in dense concentrations on account of ocean gyres, as Captain Moore’s discovery of the Great Pacific Garbage Patch has shown us.

In its summary, the 2009 UNEP report Marine Litter : A Global Challenge, states that marine debris are ‘an environmental, economic, health and aesthetic problem’. We are all too familiar with the environmental impacts of marine debris on marine wildlife : entanglement, ingestion, suffocation, etc. Obviously, marine debris evidently cause widespread suffering of marine animals. Concerns have also been raised about the effects on the oceans’ food chain. High concentrations of PCBs, DDT, and a range of other persistent organic pollutants (POPs) have been absorbed and accumulated in the food chain. Invasive alien species transported by the debris have destroyed certain local ecosystems.

Besides the impacts on marine wildlife and ecosystems, marine debris affect humans as well. The fouling of beaches and other coastal areas has been costly and controversial. Many coastal communities must pay for their own beach cleanup. While cleanup is expensive, the economic impact on tourism and related industries may be even far greater. Other examples are : damage to fishing boats and gear, to coastal installations, as well as damage to people’s health.

Legal Responses to Marine Debris Pollution

Solving this problem of marine pollution is a very complex and challenging enterprise. In particular, its legal framework. Various international and regional instruments, domestic and local laws and regulations apply directly or indirectly to marine debris pollution. International authorities concerned with marine debris and ocean dumping include the Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter (London Dumping Convention), its 1996 Protocol, the International Convention for the Prevention of Pollution from Ships (MARPOL), its Annex V on garbage, agreements concluded under the United Nations Regional Seas Programme, the OSPAR Convention, and the 1982 Law of the Sea Convention. Of growing significance is also the EU Marine Strategy Framework Directive.

The conspicuously global nature of the marine debris problem indicates that a potential role of significance is reserved for international environmental law. However, not all international and regional instruments are legally binding, and not all have a strong focus on marine debris and plastic pollution. In his recent article "Managing Marine Litter : Exploring the Evolving Role of International and European Law in Confronting a Persistent Environmental Problem", Arie Trouwborst concludes that on the one hand, the situation with regard to marine litter would have been worse without international environmental law, but on the other hand, international environmental law has still unfulfilled potential. Due to its inherent limitations, international environmental law cannot provide for more than a ‘thirty percent solution’ to environmental problems.

That leaves a remaining seventy percent to be provided by domestic laws and regulations, to politics, economics, technology, public awareness, etc. In two articles (see Baur and Iudicello, "Stemming the Tide of Marine Debris Pollution" and Weinstein, "Main Ingredient in “Marine Soup”") the importance of domestic legislation and action as a solution for this global environmental problem is shown.

If we want to keep our oceans sound and healthy, more (inter)national action has to be taken to counter this huge environmental problem. Recent initiatives as the Waves of Change : Global Lessons to Inspire Local Action, 5th International Marine Debris Conference, Honolulu, Hawai'i, March 20-25, 2011, show growing interest in and commitment to preventing, reducing and managing marine debris and plastic pollution.

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