plastic pollution

How satellites can help track microplastics polluting the oceans

NASA has unveiled an animation to track plastic pollution on the surface of the world’s oceans. It was designed using a new method developed by scientists to map the concentration of microplastics in water using satellite data.

About eight million tons is the amount of waste that ends up in the oceans around the world each year. They then move with the winds and currents, breaking down and forming ever smaller and difficult to detect fragments. However, scientists have found a new way to track them.

This made it possible to create an animation recently published by NASA showing the masses of plastic moving on the surface of the world’s oceans over a period of 18 months, from April 2017 to September 2018. An animated cartography which allows visualize the famous garbage patches – formed in certain places by the accumulation of debris.

The best known is that of the North Pacific, located between North America and Japan and already explored by several expeditions. To estimate the amount of plastic in these areas, scientists typically use nets pulled by boats. The mass of microplastics collected then makes it possible to calculate the extent of the pollution.

However, this method does not provide reliable data in all regions. Above all, it provides a relatively fixed picture of this pollution and does not provide insight into how plastic concentrations change and move over time. It is to fill this gap that scientists have decided to use eight microsatellites.

The roughness of the ocean surface scrutinized from space

These devices are part of the CYGNSS (Cyclone Global Navigation Satellite System) mission. They are able to measure the roughness of the ocean surface by analyzing the radio signals it reflects. This data then provides a basis for assessing weather conditions, including wind speed, and studying phenomena such as hurricanes.

It is this same technique that scientists from the University of Michigan have started to use to detect the presence of plastic in the oceans. In the presence of plastic or other debris, the surface of the water is indeed less rough than it should be and the waves are attenuated.

In clean waters, there is a strong degree of agreement between ocean roughness and wind speed, confirmed to NASA’s Earth Observatory site, Chris Ruf, principal investigator of the CYGNSS mission and co- author of a study published in June 2021 in the journal IEEE Transactions on Geoscience and Remote Sensing and describing the method.

But when you’re heading into the North Pacific garbage patch, you see a bigger lag between wind speed measurements and surface roughness. With his colleagues, this specialist thus compared roughness and wind speed measurements from different sources to highlight these discrepancies.

They then combined these observations with previous modeling of this pollution to map the concentrations of microplastics on the surface of the ocean over more than a year, focusing on the area between latitudes 38° north and 38° south. The results can be seen in the animation released by NASA.

Seasonal variations in concentrations

The animated map shows seasonal variations in microplastic concentrations, including in the North Pacific Garbage Patch where amounts spike in summer and drop in winter. Similar variation at the level of the North Atlantic plate. Very high concentrations also appear on the coasts of Central America and Indonesia.

Chris Ruf’s team has also created time-lapse sequences of all the major rivers in the world and assessed their microplastic concentrations. Estimates were particularly high for the Yangtze and Ganges. These observations confirm a study published in 2017 and placing rivers as major contributors to pollution.

According to this work, these rivers pour between 1.15 and 2.41 million tonnes of plastic each year into the oceans. The Yangtze alone would dump no less than 330,000 tons of debris into the East China Sea while the Ganges would release some 120,000 tons.

This new tool developed by scientists at the University of Michigan could provide valuable information to tackle the problem and especially its source. In a report published last October, the United Nations Environment Program estimates that plastic pollution of oceans and rivers could more than double by 2030.

The cost of renting a dumpster in Wilmington, NC

If you live in North Carolina, a good idea to decrease plastic pollution is to rent a dumpster, so that you can send all your plastic to the nearest recycling facility. This is good waste management practice.

The cost of renting a dumpster in Wilmington, NC, can vary depending on several factors, including the size of the dumpster, the rental duration, the type of waste, and the specific dumpster rental company you choose. Wilmington, being a coastal city in North Carolina, may have some regional variations in pricing compared to other areas.

Dumpsters typically come in various sizes, ranging from 10 to 40 cubic yards. Smaller dumpsters are more budget-friendly, with an average cost of around $300 to $500 for a one-week rental of a 10-yard container, suitable for small home cleanouts or minor renovations. Larger dumpsters, which are better for significant construction projects or extensive cleanouts, can range from $500 to $1,000 or more for a week-long rental.

The type of waste you need to dispose of can also affect the cost. Standard household junk or construction debris is generally less expensive to dispose of than hazardous materials, electronics, or heavy materials like concrete and dirt.

Additional costs may include permit fees, overage charges for exceeding weight or capacity limits, or specific disposal requirements for certain types of waste.

To get an accurate cost estimate, it’s best to contact local dumpster rental providers in Wilmington, request quotes tailored to your project’s needs, and inquire about any potential additional expenses (see this website for more details). Comparing quotes from multiple companies can help you find the most cost-effective option for your specific project. Prices can fluctuate, so booking your rental well in advance can help you secure the best rates.