Satellite-Based Monitoring of Floating Plastic in the Ocean: A New Feasibility Study

Plastic pollution in marine environments is a growing global problem.

“The total amount of plastic in the ocean and on our beaches is largely unknown, but it is estimated that 95% of marine debris floating on the surface is plastic. This makes plastic the main focus of most marine litter monitoring strategies,” explains Nellie Sofie Body, a project engineer at NGI.

Monitoring and mapping marine litter is crucial for developing effective strategies to reduce and eventually eliminate ocean plastic waste. Worldwide, governmental strategies are being implemented to combat marine litter. Still, the effectiveness of these strategies is difficult to estimate without tools for systematic monitoring over broad spatial and temporal scales.

NGI and SALT Collaborate for the Norwegian Environment Agency

SALT is an independent research and advisory company in Svolvær specializing in marine pollution, marine management, and coastal development, with the goal of contributing to sustainable oceans and proactive coastal development.

In collaboration with SALT, NGI (Norwegian Geotechnical Institute) recently completed an exciting feasibility study for the Norwegian Environment Agency. The study examined the potential for a satellite-based monitoring and alert system for floating plastic in the ocean. The project involved Nellie Sofie Body, Benjamin Allen Lange, and Regula Frauenfelder from NGI, as well as Johanne Rydsaa, Marthe Larsen Harr, and Carl Höjman from SALT.

Challenges and Recommendations

One of the biggest challenges is the lack of data for validating satellite detection from Norwegian areas.

“This means we do not know how much floating plastic is in Norwegian waters or where it might accumulate. Therefore, initiating a monitoring program with a pilot period focused on collecting such data and testing, evaluating, and further developing existing methodologies to adapt them to Norwegian conditions is recommended,” Nellie continues.

Technological development in this field has largely been based on fieldwork in milder latitudes like the Mediterranean. Transferring the methodology to the Norwegian coast is challenging, as the harsh climate, wind and waves, many clouds, and darkness create difficult conditions for satellite monitoring. The report describes adapting to these unique Norwegian conditions and recommends setting up a possible Norwegian monitoring and alert system.

The Way Forward

This study marks an important step towards better monitoring of plastic pollution in Norwegian marine areas and directly contributes to the UN Sustainable Development Goal 'Life Below Water.' Floating macroplastics larger than 10 meters are one of the indices included in this goal.

“By implementing the recommendations from the report, we can better understand the extent of plastic pollution and develop more effective strategies to combat this global problem,” she concludes.