Global Estimate of Marine Plastic Pollution

In 2014, international scientists collaborated with 5 Gyres to publish the first Global Estimate of Marine Plastic Pollution, and determined that 5.25 trillion particles of “plastic smog” weighing in at 270,000 tons pollute our oceans worldwide. The Estimate is updated regularly and is informed by Expedition and TrawlShare research.

This map shows the 1,571 field locations where count density was measured during 5 Gyres Expeditions and through surveys conducted by research partners. For more information on the 2014 Global Estimate, please visit our Publications page.

This map shows the 1,571 field locations where count density was measured during 5 Gyres Expeditions and through surveys conducted by research partners. For more information on the 2014 Global Estimate, please visit our Publications page.


The TrawlShare program provides scientific trawls and protocols for citizen scientists to collect data on marine plastic pollution, raise awareness about this important issue, and contribute to a more robust global dataset. All data is used to update the annual estimate of plastic pollution on the oceans’ surface. This program provides a unique hands-on experience to carry out research that is essential for 5 Gyres to fulfill our mission, both to better understand plastic pollution on a global level and cultivate plastic pollution leaders. 

Launched as the Travel Trawl program in 2014, TrawlShare now includes 35 trawls made specifically for the program. Citizen scientists and partners have provided global data from The Bahamas, Hong Kong, Arctic, and other regions.  If you’re sailing through one of the five gyres, contact us to borrow a trawl and collect scientific samples to contribute to our global dataset.

Solar Plastic Kiln

The Solar Plastic Kiln melts common plastic ocean pollution into useful materials like bricks or boards. These units are solar powered, allowing them to be deployed remotely on any island, beach or community where plastic waste in abundant. The simple idea is to create a low-cost method that increases the value of a common pollutant plaguing our seas.  

This project created the world’s first fully mobile, sustainable solar capable plastic recovery kiln for rapid recycled product creation in the form of structural building elements, such as bricks. The technology is a low-cost, and accessible platform that uses solar panels to create electricity, heating elements (such as found in a toaster oven) to heat thermal fluids, and simple aluminum molds to recycle the plastic waste. 

5 Gyres worked with Swift Engineering and Packaging 2.0 to develop and execute the project. The Solar Plastic Brick Kiln piloted in The Bahamas in early 2016.

San Francisco Bay Microplastic Program

Beginning in 2016, 5 Gyres partnered with the San Francisco Estuary Institute to design and execute a research program designed to foster better understanding of the pathways and distribution of microplastics in the Bay and adjacent National Marine Sanctuaries. The findings will provide essential baseline data needed to evaluate the effectiveness of recently implemented pollution prevention policies, including the federal microbeads and state-wide plastic bag bans, as well as future bans of single-use plastic items such as bottles, shopping bags, and polystyrene. 

Tracking California Trash (2014-2016)

5 Gyres partnered with the State Water Resources Control Board, the Bay Area Storm Management Agencies Association (BASMAA), and the San Francisco Bay Regional Water Quality Control Board to carry out the Tracking California’s Trash Project (TCT), a project that included multiple large-scale efforts to track and understand trash in California's waterways. TCT aimed to help cities and counties better understand if current efforts to reduce trash (product bans, increased street sweeping, catchment basins, etc.) from entering the marine environment are effective.

5 Gyres was responsible for developing and testing methods to monitor trash (defined by the state as >5mm) in a range of receiving waters (rivers, channels, streams, and creeks). Monitoring was done at four locations in California, three in the San Francisco Bay Area and one in Los Angeles. In addition to selecting receiving waters ranging in size, channelized and natural rivers were analyzed. Samples were collected using five different trawls during dry and wet weather, with a focus on collecting the "first flush," after it rains. Please visit our Publications for the report abstract, or contact us for the full report.

Plastic Beach Project (2013-2014)

The Plastic Beach Project aimed to better understand the distribution of microplastics on beaches around the world by working with a network of citizen scientists. This information helped support local policy initiatives to limit single-use plastic items, determined that microplastics are a concern on the beaches analyzed, and helped others comprehend the vast scale of global plastic pollution.

Long-term goals of the Plastic Beach Project were to gather information on plastic pollution on an international level. Between 2013 and 2014, 5 Gyres focused on the West Coast of the United States, carrying out research at 16 beaches and reaching over 350 people directly. 5 Gyres also collected data in Bermuda and Iceland in 2014 during the 2014 Arctic Expedition, along with carrying out additional events in Rhode Island after the 2013 Expedition from Bermuda to Rhode Island. 

Though the Plastic Beach Project is not actively hosting beach events in 2016, our citizen science protocols are used by individuals and organizations around the world.