Challenge 2: Ending and Recovering from Marine Debris

## THE PROBLEM

The ocean is downstream from everywhere else on Earth. Many major river systems and waterways in population centers have a direct path to the oceans, resulting in more than 5.25 trillion pieces of plastic debris weighing over 250,000 tons, among other trash, being deposited in the ocean. Marine debris continues to rise as a result of increased human activity in river basins and ineffective waste management systems across the globe. This has lead to debris (including clothing fibers, plastics, and other pollutants) conglomerating in massive ocean garbage patches. These patches are a challenge to address as a result of the composition and depth to which the trash penetrates. Plastic marine debris breaks down into smaller pieces until they are microscopic and distribute throughout the water column. These areas are in the global commons and, with no clear owners, responsibility is diffuse.

## THE CHALLENGE

Reduce plastic marine debris in the oceans by 90% in 10 years, and undo the harm that has already been done.

The Marine Debris Grand Challenge would focus on the three elements
of the input system: (a) reinventing material goods at the chemical level so that rogue trash entering the ocean can quickly and easily biodegrade, (b) stopping plastic pollution and other debris from entering the ocean, and (c) creating innovations to manage and clean up the trash already in the ocean and reversing its negative side effects.

## PROBLEM STATEMENT

Around 80% of marine debris floating in the world’s oceans is plastic. Although most marine debris is from the land, an additional source is from galley waste and other trash from ships, recreational boaters and fishermen (nets and floats), and offshore oil and gas exploration and production facilities.
 At present, 15—40% of littered or dumped plastic enters the oceans every year. More than 5.25 trillion pieces of plastic debris are currently in the ocean, increasing by 4—12 million metric tons per year, with an average of 13,000 pieces of floating plastic per square kilometer of ocean. However, the exact quantity of particulate plastic (or microplastics) in the ocean is still unknown and difficult to measure. Ocean plastics break down into smaller pieces until they are microscopic. Scientists still do not know where more than 99% of ocean plastic debris ends up, how long it takes to degrade, and what impact it is having on marine life. What is known is troubling. Ocean plastics absorb chemical pollutants, becoming highly toxic. Studies have shown that the concentration of toxic chemicals, such as PCBs and DDT, can be up to a million times greater in plastic debris than the concentrations found in seawater. Such large and small debris are eaten by sea life, including fish, sea birds, turtles, and marine mammals, introducing toxins into the food chain, and causing problems through blockage or perforation of the digestive tracts of sea life. According to recent papers, many more organisms ingest small plastic particles than previously thought. Floating debris can also negatively affect physical habitats such as clogging up coral reefs or mangroves, reducing their productivity.

Despite efforts toward standardized waste management in North America and Europe, the net amount of nonbiodegradable matter entering the ocean continues to grow. This is especially true for Asian and Latin American countries where growing participation in consumer economies outstrips the capacity (or frequently the existence) of waste management facilities. No nation takes full responsibility for cleaning up marine pollution in international waters. Even if a country were to do so, the clean up would only temporarily solve a fraction of the problem, as existing waste disposal patterns would soon replace what was removed.

## EMERGING SOLUTIONS

Any solution needs to change the impact of products entering in the oceans, reduce the input of such products, and extract the debris
that is already there.

**Rethinking Plastics:** Stopping plastic pollution is a two pronged initiative that simultaneously (a) accelerates green chemistry substitutions for materials innovation toward ocean-friendly polymers that will replace traditional plastics in everyday goods, and (b) develops a closed loop, ecologically benign waste management system for both the developing and developed worlds. As the developing world industrializes, it presents opportunities to rethink assumptions and leapfrog traditional technology.
Several efforts to create ocean- biodegradable plastics are underway from large chemical companies, food and beverage distributors, and small startup companies. Mango Materials transforms waste methane into biodegradable plastics that are economically and functionally competitive with oil-based plastics. The methane is captured and fed to naturally occurring bacteria that produce the biodegradable plastic. Once that product is no longer needed, the polyhydroxyalkanoates (PHA) will break down in a microbe-rich environment producing methane that can be turned back into PHA with Mango Materials’ cradle-to-cradle process. Biodegradable plastic could be used in consumer goods, as well as for fishing gear, like nets. Think Beyond Plastic is an incubator and small-scale venture fund to build products and markets for biodegradable and recycled plastic products. Similar developments are occurring with replacements for Styrofoam. Evocative Design has developed packing materials that use agricultural fibers and mycelium (mushroom) as a replacement.

**Materials Breakdown:** The bacterium, *Ideonella sakaiensis,* breaks down the plastic by using two enzymes to hydrolyze PET and a primary reaction intermediate, eventually yielding basic building blocks for growth. The species fully breaks down one of the most common kinds of plastic called Polyethylene terephthalate (PET). This type of plastic is often used to package bottled drinks. Link to Science Article.

*Styrofoam-eating mealworms.* Researchers have learned that the mealworm can live on a diet of Styrofoam and other types of plastic. Inside the mealworm's gut are microorganisms that are able to biodegrade polyethylene, a common form of plastic, according to new studies published in Environmental Science and Technology by co-authors Professor Jun Yang and his doctorate student Yu Yang of Beihang University, and Stanford University engineer Wei-Min Wu.

**Waste Stream:** Because most plastic and other debris that reaches the ocean passes either through rivers and streams or wastewater/stormwater outfalls, there is significant opportunity to disrupt the waste stream. Currently, there is little innovation occurring in waste stream technology. But the ability to filter, sort, and separate materials cheaply could both incentivize the creation of new products from recycled materials, as well as prevent these materials from reaching the ocean. This is particularly important for microplastics and other nanopollutants. Finally, there are also schemes to remove plastics before they hit the waste stream by creating building materials out of recycled plastics, such as plastic bricks.

**Ocean Friendly Products:** Ocean friendly products constitute objects and systems designed to be ocean friendly, not ocean trash. Solutions include ocean friendly product design for consumer and industrial products and a shift toward closed loop material goods; systems design for waste management that is accessible for all socioeconomic groups; improved infrastructure and ship design for ocean transportation of goods; and closed loop innovations in textile recycling such as that innovated by Worn Again, so that used clothes and textiles can be collected and processed back into new yarn, textiles, and clothes.

**Extraction and Reuse:** There have been a number of attempts to passively or actively clean up ocean plastic. The area involved and the relatively low density of plastic in the ocean have made most ideas untenable. The city of Baltimore has attempted to address this problem at its source through the solar and current powered Inner Harbor Water Wheel, which collects trash off the Jones River before it reaches Baltimore Harbor.

One effort that has received a significant amount of attention for both its audaciousness and its innovative approach is Boyan Slat’s Ocean Cleanup Initiative, one of the first attempts to intercept and remove plastics from the ocean through large arrays. The technical and financial feasibility of the design has attracted significant criticism—large V-shaped barrier arrays anchored on the sea floor concentrate plastics carried on ocean currents toward a central platform, which extracts the plastic and stores it for transport. However, Ocean Cleanup has achieved significant support and funding. According to claims, the array is estimated to be nearly 8,000 times faster and 33 times cheaper than conventional cleanup methods, but the criticism is that it vastly over-estimates its ability to solve the problem, and is not financially sustainable. Time will tell.

Bureo Inc. is a company that has established a fishing net collection and recycling program along the coast of Chile, transforming the waste into skateboard decks. Their program, called “Net Positiva,” buys ripped nets from fishers who would otherwise need to dump them in the ocean to avoid prohibitively expensive dumping fees. Envision Plastics has partnered with Method to create bottles with 5% post-ocean high-density polyethylene, collected from beaches. The challenge is to create high-end consumer products with a higher degree of post-ocean plastics, but at equivalent costs to existing plastic products.

Additional Innovations

Solar Powered Vaccum

## ADDITIONAL RESOURCES

The World Economic Forum Report: The New Plastics Economy: Rethinking the future of plastics