How the Ocean Cleanup Array Fundamentally Misunderstands Marine Plastics and Causes Harm


The road to hell is paved with good intentions. The Ocean Cleanup array, designed to clean plastics from the ocean like a baleen whale, is one of these good intentions: experts in marine plastics, including myself, say it’s a bad idea.Technological fixes like the Array do harm to the larger project of ending plastic pollution, which is a complex social, environmental, and economic problem. It is also going to damage and kill marine life.

The Array prototype is a 2 kilometer floating boom with a skirt that collects plastics, then sends them through a spinning centrifuge to get rid of water and non-plastics, then finally onto a platform for storage and eventual shipping. It’s set to launch between Korea and Japan in 2016. The idea is immensely popular and every few months since it’s inception several years ago, makes the rounds on social media and news. And every time, experts in fields from microbiology to oceanography say that not only will it fail to work, but it will–and is– causing harm. The problem would not inspire so much criticism except that it is both very popular and the creators do not appear to be listening to earnest concerns of the problems and perils of their project.

There are ample technological arguments against the physical feasibility of the Ocean Cleanup Array forwarded by a wide range of experts, from the expert peer review by Drs. Kim and Goldstein to environmental journalism by NGOs that succinctly list technical concerns. Some of these are about ocean plastics, such as pointing out that the Array only appears to collect plastics larger than 2cm, and the vast majority of floating ocean plastics–about 98%– are less than 5mm in size. Some are physical critiques, such as the booms need to be moored in waters up to 4,000 meters deep to be stable enough for collection–twice the current maximum depth at which ships or other structures have ever been moored. Most of these problems are engineering problems.

Beyond Technical Critiques: How the Ocean Cleanup Array Causes Harm

Avoiding the Root of Plastic Pollution

Of greater issue are biological, ecological, and social concerns that argue that the Ocean Cleanup Array causes harm. First and foremost among these is that the Array doesn’t address the root of marine plastic pollution and diverts money and attention away from ceasing, mitigating, and slowing the creation of plastic disposables in the first place. If you think of marine plastics as a stock and flow problem, where plastics are flowing into the oceans from land and accumulating, then the Array deals with the stock, but not the source of plastics. The leading research, education, and advocacy organizations around marine plastics seek to ban microbeads, reduce the production of disposables, and otherwise stem the flow of plastics as well as dealing with stock, but stock is secondary. It’s like bailing out a sinking boat before you’ve plugged the hole that’s sinking it.

Stock and flow for marine plastics. Image by Max Liboiron.

Stock and flow for marine plastics. Image by Max Liboiron. CC BY-NC-SA 4.0

Moreover, once any collected marine plastics are brought onto land, they are likely to eventually end up back in the ocean. Plastics exist in something called “deep time,” geologic timescales that far outstrip the timescales of species. Rather than degrade into their constituent molecules, plastics fragment into smaller and smaller pieces of plastic, and according to laboratory studies, this “degradation of cm-size plastics results in microscopic particles that remain in Earth’s environment indefinitely” (Cooper, 2010: 652). Moving plastics from the water to landfills that will eventually erode or be covered in water is an act of deferring pollution, not stopping it. It’s moving pollution around in space while it endures over time.

Even recycling is a problem. The most pressing issue is that recycling perpetuates disposability. First, it “greens” disposable packaging because it seems like there is less environmental harm and thus gives it social license that allows disposables to continue. Secondly, some recyclables are used to make more disposables. Both  contribute to more ocean plastics. But recycling also consumes energy, requires virgin materials, and produces pollution. For plastics in particular, recycling is not a robust environmental or economic process. There are many, many types of plastic–well beyond the 7 types identified on the bottom of plastic packages–and each one has a different melting temperature, different set of plasticizing chemicals (like bisphenol A/BPA, among hundreds of others), and different densities. This makes them a lousy material to use as raw materials because they just aren’t materially similar enough to process. Plastics fished from the ocean that are also carrying contaminants (plastics absorb up to one million times more chemicals than the surrounding water!), bleached by sun, biofouled with microbes, and full of salt will be even more heterogenous and harder to use as raw stock material. This doesn’t make recycling impossible, but it does make it unfeasible as a solution to plastic pollution generally, and for the Cleanup Array specifically.  For more on the environmental and economic limits of recycling, see Samantha MacBride’s Recycling Reconsidered, one of the most comprehensive and insightful books on the topic.

Ecological Harm

Scientists, often marine biologists and those that work on the ocean (see list below), have raised concerns about harm to ecosystems and marine life that the Cleanup Array will cause. Currently, there is no environmental impact assessment for the Array, a document that would assess the environmental consequences of the project. Scientists have the following concerns:

By-catch and By-kill 

Diagram of the skirt that catches plastics, from the Ocean Clean Up Array feasibility study.

Diagram of the skirt that catches plastics, from the Ocean Clean Up Array feasibility study.

By-catch refers to catching things in a net other than what you are fishing for. A popular example is that tuna harvesters often catch dolphins. One of the main concerns raised by marine biologists is that massive numbers of marine animals, from plankton to swordfish will be killed or injured during the clean up process. The skirt that collects plastics will also collect marine life (see left). While the report says that the plankton will survive their capture and live through the spinning centrifuge that separates plastics from water in the final collection, scientists such as Drs. Kim and Goldstein warn:

Most zooplankton don’t survive being caught in a standard manta net, never mind being spun in a centrifuge. They might still be twitching, but they have lost a lot of their important parts, like antennae and feeding apparatus. When we want to capture live zooplankton, we use special live-collection nets and are very, very careful. […] I am highly skeptical that any significant proportion of zooplankton are viable after caught in a net and spun at 50 RPM.

As for larger marine life, the feasibility study itself says this:

Highly migratory species will be highly affected by this project. Swordfish, marlin, sailfish, sharks, tuna-like species are all highly susceptible to being caught in the holding tanks, and possibility diverted by the booms into the platform.

Machines that clean can’t differentiate between living and non-living “particles,” and they can’t respond to situations and contexts that occur in situ. Many of us are concerned that the Array is akin to a giant ghost fishing net that is fishing for plastics, but collecting marine life as by-catch– that is, it is replicating one of the types of harms marine plastics cause in the first place.

Creation of Plastic Hot Spots and Spills

In 2001, a team of researchers compared the quantities of plankton to plastic in the North Pacific central gyre, one of the areas of highest concentrations of plastic in the oceans known at the time. They found that plastics outweighed plankton by six to one. They thought a comparison of food stock–plankton– to things that could be mistaken for food stock–plastics– was important for estimating the severity of harm that plastic concentrations might cause for the food chain.

By concentrating plastics, the Array will create hot spots of marine plastics, changing the ratio of plastics to food stocks in areas. This will happen as a matter of course, since this is how the technology is designed to work, but it can also happen if the technology breaks, tips, cracks, or otherwise spills.

Disruption of Existing Ecosystems

The booms of the Array need to be securely fastened to the ocean floor for stability, which will disrupt, disturb, and damage benthic (sea floor) ecosystems, much like anchors. Sea floor ecosystem communities often contain slow-growing plants and animals that are particularly susceptible to damage.

A colony of limpets attached to a diving mask, found washed ashore on a beach. Photo by Andrea Westmoreland from DeLand, United States. CC BY-SA 2.0)

A colony of limpets attached to a diving mask, found washed ashore on a beach. Photo by Andrea Westmoreland from DeLand, United States. CC BY-SA 2.0

Another often overlooked ecosystem lives on marine plastics. The unique plant, microbial, and animal communities that grow on ocean plastics has been called the “plastisphere.” The same phenomenon, where plastic objects are colonized by living communities, is also called “biofouling” when it is seen as a problem for boats and other equipment: having your smooth device turn into a textured ecological community slows things down and makes them heavy. To get rid of biofouling, there are chemicals called biocidal coatings. The most widely used are compounds in the tributyltin family, which are known to leach into seawater and pose documented risks to microorganisms and other marine life.

So clean up disrupts ecological communities living on the plastic itself, and keeping biofouling from creating drag and unwanted weight on the Array is also likely to endanger marine life.

The Clean Up Array in the wider picture of depollution

Screenshot from the Ocean Clean Up Array website. Captured June 7, 2015.

Screenshot from the Ocean Clean Up Array website. Captured June 7, 2015.

How you define a problem determines solutions in advance. Basically, The Cleanup Array has mischaracterized the problem of marine plastics and of how pollution works generally. Cleaning up, depollution, and remediation are terms for physically removing unwanted particles from an environment and placing them somewhere else.

However, this concept is old-fashioned because “clean up” is impossible for many wastes, including marine plastics. First, the extreme longevity of plastics mean that cleaning up is just moving the particles around in space as they endure in geologic time– they do not go away, and this temporality means than any containment is temporary. This is as true of plastics as it is of nuclear waste, orbital debris, persistent organic pollutants (POPs), and is a defining feature of waste issues in the 21st century. Secondly, many wastes are inextricably part of their contexts. Marine life lives on plastics, and plastics exist inside of marine life (see image of plankton below). Tiny plastic particles have been found circulating in the blood of mussels. This expands the plastisphere to include not only the habitats on individual plastic fragments, but entire landscapes, bodies, and even entire oceans.

Images of microplastic ingestion by plankton. From Cole, Matthew, et al.

Images of microplastic ingestion by plankton. From Cole, Matthew, et al. “Microplastic ingestion by zooplankton.” Environmental science & technology (2013).

This ubiquity, permanence, and inextricability challenges not only current definitions of pollution, but also of clean up. For plastics and other forms of waste, clean up is a stop-gap at best, not a solution.

The Clean Up Array in the wider picture of wicked problems and technological fixes

In 1973, two engineers, Horst Rittel and Melvin Webber, wrote “Dilemmas in a General Theory of Planning.” The dilemma was this:

“[W]e are all beginning to realize that one of the most intractable problems is that of defining problems (of knowing what distinguishes an observed condition from a desired condition) and of locating problems (finding where in the complex causal networks the trouble really lies). In turn, and equally intractable, is the problem of identifying the actions that might effectively narrow the gap between what-is and what-ought-to-be.” (159)

They coined the term “wicked problem” to describe engineering problems that were social, technical, and cultural all at once and so difficult to define. Even if these problems had technical aspects, there was no “technological fix;” they could not be solved with technical solutions.

The Cleanup Array is a technological fix for a wicked problem. It’s not a coincidence that leaders researching marine plastics such as 5 Gyres and Algalita Marine Research Foundation, do education, advocate for policy change, engage in public outreach, and work with designers in addition to their research. They work to define the problem of plastic pollution as a complex issue that starts on land. Engaging with wicked problems creates a new research ethics, according to Rittel and Webber:

 “You may agree that it becomes objectionable for the planner to treat a wicked problem as though it were a tame one, or to tame a wicked problem prematurely, or to refuse to recognize the inherent wickedness of social problems.” (161)

This isn’t to say that cleaning up is inherently a bad idea; it is to say that treating a clean up as a solution to the problem of plastics is a bad idea. It refuses to recognize the inherent wickedness of the problem. Indeed, some scientists are proposing beach clean ups as one less expensive, less harmful alternative to the Array, so clean up in and of itself is still part of the plastic pollution tool kit. There have been many other technological clean up ideas before the Array as well: Project Kaisei’s Capturing the Plastic Vortex (which is now a research project), Veolia’s marine drone, Abundant Seas Foundation’s Pelagic Pod, and, one of the more absurdist ideas, WHIM Architecture’s Recycled Island. With the exception of WHIM’s project, none of these are touted as the solution to marine plastics. That is the problem with the Cleanup Array: there should be a diversity of proposals that deal with the problem of plastic pollution, given the sheer scale and complexity of the problem. It will take many points of view working together to solve this problem. Silver bullets and technological fixes do a great disservice to the larger project of ending plastic pollution.

As such, when there is a popular concept about how to manage waste that is based on good intentions but flawed concepts of pollution, and will actually cause more harm than good, it is the responsibility of researchers to engage with the problem. My peers have been holding up their end of this bargain to be accountable to the public: There has been a pro bono expert peer review of the Array. Individual scientists like Andrew David Thaler  ask logistical questions from a marine biologist’s perspective that also act as peer review. Algalita Marine Research Foundation, one of the leading research groups on marine plastics, calls ocean clean up a controversy. Even before the Array was invented, members of 5 Gyres, one of the other leading research and education NGOs that specialize in marine plastics, outlined why clean up is impossible and undesirable. Even some news outlets do investigative journalism and question the feasibility of the project. Yet this side of the conversation is rarely heard, and certainly doesn’t circulate as much as the more hopeful, though impossible, story of redemption promised by a technological fix.

Bibliography of Critics:

Allen, Katie. “Plastic Pollution – Preventing an Incurable Disease: Marine Research and Education.” Algalita | Marine Research and Education.
Andrew David, Thaler. “Three Facts about The Ocean Cleanup.” Southern Fried Science.
Martini, Kim. “The Ocean Cleanup, Part 1: Alternatives to Reduce Ocean Plastic | Deep Sea News.”
Martini, Kim, and Miriam Goldstein. “The Ocean Cleanup, Part 2: Technical Review of the Feasibility Study | Deep Sea News.”
Wilson, Stiv. “The Fallacy of Gyre Cleanup: Part One, Scale.” 5 Gyres, July 5, 2010.
Max Liboiron is an Assistant Professor of culture, science and technology at the Memorial University of Newfoundland. Dr. Liboiron is currently writing a book on scientific representations of marine plastics and how the relate to action. 

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