garbage patches

Plastic In Lakes | Earth Wise

August 28, 2023 By EarthWise Leave a Comment

We are always talking about the millions of tons of waste plastic that finds its way into the oceans and about the challenges of trying to remove it. A new multinational study has found that the concentration of plastics and microplastics in some lakes is even worse than in the so-called garbage patches in the oceans and some of these lakes are even in remote places around the world

Scientists from institutes in multiple countries collected water samples from 38 lakes and reservoirs in 23 countries across six continents. The samples were then all analyzed by the University of Milan to assess the presence of plastic particles more than a quarter millimeter in size.

The study found that two types of lakes are particularly vulnerable to plastic contamination: lakes and reservoirs in densely populated and urbanized areas and large lakes with elevated deposition areas, long water-retention times, and high levels of human influence.

Lakes found to have the highest concentration of plastic included some of the main sources of drinking water for communities and were also important to local economies. These included Lough Neagh in Northern Ireland, Lake Maggiore in Italy, and Lake Tahoe on the California/Nevada border. Not all the lakes studied contained large amounts of plastic. For example, Windermere, the largest lake in England, had very low concentrations of plastic in surface water.

This was the first global survey of the abundance and type of plastic pollution in lakes and reservoirs and the scale of freshwater plastic pollution is sobering indeed. There is widespread concern that plastic debris is having harmful effects on aquatic species and ecosystem function and clearly is not limited to marine ecosystems.

**********

Web Links

Plastic pollution is higher in some lakes than oceans

Photo, posted May 27, 2019, courtesy of Jonathan Cook-Fisher via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Keeping Trash Out Of The Ocean | Earth Wise

February 23, 2023 By EarthWise Leave a Comment

The Ocean Cleanup is a non-profit organization, founded in 2013 by Dutch inventor Boyan Slat, to develop and scale technologies to rid the world’s oceans of plastic. It is an organization that proudly declares that its primary aim is to put itself out of business by successfully cleaning up the oceans.

A major activity of The Ocean Cleanup is efforts to clean the ocean garbage patches that have accumulated in several places, best-known of which is the Great Pacific Garbage Patch. The effort involves use of large U-shaped floating barriers that act as an artificial coastline to trap garbage which is then funneled into a barge for disposal. Ten full-sized systems will be needed to clean up the Great Pacific Garbage Patch.

A second activity of The Ocean Cleanup is preventing garbage in rivers from making its way into the oceans. Rivers are the main source of ocean plastic pollution. The Ocean Cleanup has developed river machines called Interceptors that capture garbage for disposal. Last fall, they installed a machine called Interceptor 007 in Ballona Creek, a waterway in the Los Angeles area. In the first rainfall after installation, the Interceptor managed to stop 35,000 pounds of waste from entering the ocean in just a few days.

The original Interceptor models have been deployed in Indonesia, Malaysia, the Dominican Republic, and Vietnam. A different type called the Interceptor Trashfence is being tested in Guatemala.

The Ocean Cleanup states that if fleets of its barrier systems are installed in all the garbage patches and Interceptors in the 1000 most significant rivers, 90% of floating ocean plastic can be removed by 2040.

**********

Web Links

The Interceptor 007 Stops 35,000 Pounds Of Trash From Entering Ocean

The Ocean Cleanup

Photo, posted February 23, 2015, courtesy of Ministerie van Buitenlandse Zaken via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Microplastic Hotspots In The Ocean | Earth Wise

June 4, 2020 By EarthWise Leave a Comment

Many of us are aware of the infamous ocean “garbage patches” of floating plastic. The Great Pacific Garbage Patch is roughly the size of Texas. But over 10 million tons of plastic waste enter the oceans each year and the floating patches only account for 1% of that total. The remaining 99% of the plastic ends up in the deep ocean, generally in the form of microplastics – tiny fragments of large plastic debris that have broken down as well as manufactured polyethylene beads used in various products.

According to a new study published in the journal Science, there are actually microplastic hotspots on the ocean floor, formed by deep-sea currents that act as conveyer belts moving the tiny plastic fragments around. One of these hotspots – in the Tyrrhenian Sea off the west coast of Italy – contained 1.9 million microplastic pieces in just one square meter of seafloor. This is the highest reported value for any place in the world.

Because of their small size, microplastics can be ingested by organisms across all levels of the marine food chain and eventually find their way into human diets.

The spatial distribution and ultimate fate of ocean microplastics are strongly controlled by near-bed thermohaline currents. These are deep-ocean currents driven by differences in water density, which is controlled by temperature and salinity. Thermohaline currents are known to supply oxygen and nutrients to the flora and fauna found at the ocean bottom. As a result, deep sea biodiversity hotspots are likely to be in same places where there are microplastic hotspots.

The discovery of these deep- sea hotspots is just another reason why we need behavior and policy interventions to limit the flow of plastics into natural environments.

**********

Web Links

Seafloor microplastic hotspots controlled by deep-sea circulation

Photo, posted September 6, 2012, courtesy of Oregon State University via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

More Plastic Pollution On The Way | Earth Wise

January 31, 2020 By EarthWise Leave a Comment

Public concern about plastic pollution has been rising. More and more of us are choosing reusable grocery bags, metal straws, and reusable water bottles. We shake our heads at images of immense plastic garbage patches in the ocean. We see reports of birds with 15% of their body weight in plastic.

While all of this is going on, companies like ExxonMobil, Shell, and Saudi Aramco are ramping up production of plastic – which is mostly made from oil, gas, and their byproducts. They are doing this as a hedge against the growing possibility that the global response to climate change will reduce demand for their fuels. Plastics are part of the category called petrochemicals, which currently account for 14% of oil use. Petrochemicals are expected to drive half of oil demand growth over the next 30 years.

The World Economic Forum predicts plastic production will double in the next 20 years. The fracking boom in the United States has turned this country into a big growth area for plastic production. Natural gas prices are low which is hurting profits at fracking operations. But fracking also unearths ethane, which is a feedstock for plastic production. So plastic is becoming a kind of subsidy for fracking.

The American petroleum industry’s hub has historically been the Gulf Coast of Texas and Louisiana as well as a stretch along the lower Mississippi River. There is a slew of new projects there. The industry is also seeking to create a new plastics corridor in Ohio, Pennsylvania, and West Virginia, where fracking wells are rich in ethane.

Society in general may be increasingly concerned about the impact of things like carbon emissions and plastic pollution, but the fossil fuel industry continues to focus entirely on growth and profits.

**********

Web Links

The Plastics Pipeline: A Surge of New Production Is on the Way

Photo, posted January 10, 2015 , courtesy of Daniel Orth via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.