Satellites will allow us to track the movement of microplastics in the sea and develop more effective strategies for pollution management.
Maybe this way we can understand the scale of the problem?
Over 8 million tons of plastic waste reach the sea each year.
They join approximately 170 trillion plastic particles weighing about 2.3 million tons floating on the ocean surface.
The increasing amount of plastic entering the ocean each year and breaking down into smaller and smaller particles makes the need to clean the ocean a major challenge.
A new study deals with a method for identifying and monitoring plastic particles using satellites, which can signal in real time the spread patterns of microplastics in seawater and oceans.
Traditional methods for monitoring microplastics are very cumbersome says Kurtzer, who is developing a remote sensing model for detecting and monitoring microplastics in the sea.
“You need to physically go to the site, especially when it is in the middle of the sea or ocean the voyage and logistics are expensive, and you still need to map each area, deploy a net, collect it, and count manually.
In addition, due to ocean currents, what we monitor one day will be in a different place the next day. These are time consuming tasks, and the chance of monitoring them consistently is low.
Remote sensing actually solves these problems because there are constant satellite images that are updated and allow monitoring microplastics consistently.”
In her research, Kurtzer develops a method to help understand the scale of microplastic occurrence the types and concentrations of these particles in the marine environment.
Plastic waste can be divided into two types: macroplastics particles larger than 5 millimeters and microplastics particles smaller than 5 millimeters and larger than 100 nanometers.
While most waste seen on beaches or in water, like bottles, is actually macroplastic, identifying microplastics requires much closer observation.
However, to detect it efficiently and consistently, it may actually be better to look from afar.
“The difficulty of identifying microplastics on a large scale led me to try and optimize the process through research that is both computational and AI-based,” she says. “We focused on two types of plastic, polyethylene and polystyrene, which are the most common types alongside polypropylene, which currently is not included in the model due to lack of data.”
Polyethylene, as mentioned, is one of the most common types of plastic. It is usually transparent and lightweight, used for bags and plastic packaging, bottles, disposable cups, polyester fibers, and more. Polystyrene, known in its foamed form as Styrofoam, is one of the plastic types whose single-use applications have been banned in more than 60 countries due to its harmful properties to the environment and humans.
To detect microplastics so small from such a distance, the model uses information about material properties, such as the degree of light reflection of each type of plastic. “Each type of plastic has a significantly different signal due to its light reflection,” says Kurtzer. “With sensors, we can understand whether it is polystyrene or polyethylene.
The algorithm is generic enough that if we have information on additional types of plastic, we can identify them in the future as well.”
Furthermore, “We found that the higher the concentration of microplastics in a given area, the higher the reflection. In other words, both the type of plastic and the concentration of plastic particles matter.”
Unlike macroplastics, microplastics are abundant in the ocean even outside large waste accumulations where plastic products gather. “When building the algorithm, we did not focus on a specific area or on waste accumulations, but built a general algorithm that can be used in any context,” explains Kurtzer. “We know how water behaves and can estimate flow paths. Using satellites and microplastic detection, we can track their movement in real time.”
Without a significant change in global plastic production and the waste discharged into the ocean, swimming in it will soon feel like wading through a “soup” of plastic particles, and plastic waste in the ocean could nearly triple by 2040. The international plastic treaty, which was supposed to be finalized last November as part of an intergovernmental negotiation committee, did not reach the desired outcome and will reconvene in 2025.
The model will allow mapping microplastic pollution in marine systems accurately and extensively over large areas, aiming to better preserve the marine ecosystem and enable improved environmental policy planning. “Our algorithm opens a window for microplastic monitoring research. From here, it will be possible to refine, develop, and eventually replace current methods. We can make them more consistent, user-friendly, sustainable, and cost-effective so we can clean all the plastic from the marine environment,” concludes Kurtzer.