Want to create multi-layered map of marine plastic litter

by | 9. June 2020 | News

Monitoring of ocean space is becoming increasingly digital, and technological solutions are developing at a rapid pace. This also provides new opportunities for mapping and monitoring of plastic litter in the sea. In January this year, the Marine Recycling Cluster (MRC) business cluster was included in the national cluster program Norwegian Innovation Clusters, which is funded by Innovation Norway, the Research Council and Siva.

The group, which has set itself the goal of becoming Norway’s technological spearhead in the fight against global marine pollution, has made mapping one of its main tools in a concept called the Marine Clean-up Toolbox. The concept has been presented to authorities in Indonesia and Thailand, and has attracted great interest.

Detects plastic in the ocean

The mapping tool is composed of five levels of data: satellite imagery, drone imagery, gliders, ocean current modeling and field data. The tool should make it possible to map deposits, concentrations, movement patterns and types of plastic that float in the surface or are located in the beach zone, and can be used worldwide. In Asia, the major problem is that household waste flows into the sea from the rivers, while in the north the biggest problem is plastic waste from industry, aquaculture and fisheries.

– The mapping tool will help authorities to better plan cleanup and prevention, says Terje Kristensen, who is responsible for the drone operations at Andøya Space Center.

Satellites can give us snapshots of large concentrations of plastic, while sensors on drones and gliders can give us more detailed data from the worst areas. Ocean flow analyzes give us patterns of movement, and field data can reveal where the plastic comes from – making it easier for manufacturers and polluters to be held accountable. Although prevention of plastic leakage to the seas is of the utmost importance, mapping and cleaning of litter will also be very important and necessary for many years to come. Marine litter is a problem that will take time to solve, and meanwhile effective methods for clearing, which is urgent, must be developed, Kristensen believes.

Sensors on drones and gliders can provide more detailed data from the worst areas. Photo: Elbit Hermes 900 drone (illustration photo from ASC)

Analyzes of ocean currents

A key player in the group is Akvaplan-niva AS. They are world leaders in analyzes of ocean currents, and use hydrodynamic models to map the operation of plastics and other particles with the water masses. The company also operates marine gliders (drones without motor) with a number of sensors for observations of the marine environment.

– Together with international partners, we will map both macro and microplastics using measuring instruments placed on gliders that are driven by waves, wind and solar energy, says Salve Dahle at Akvaplan-niva.

Marine litter in the north. Photo: Marthe Larsen Haarr, SALT

Littering in the beach zone

Another important partner is SALT, which today is probably the largest private environment in Norway for macro plastic waste. They have ten employees with doctoral or master’s degree expertise who concentrate exclusively on this problem area.

GRID-Arendal is a leader in GIS models, and is already collaborating with SALT on mapping marine plastic waste into the beach zone.

– There has been a strong spotlight on microplastics, but we need to focus at least as much on macroplastics,” says general manager of SALT, Kjersti Busch. She points out that macroplastics (often defined as plastic pieces over 5mm) are the most important source of microplastics and easier to deal with. The most effective method for clearing marine plastic waste is to concentrate efforts on accumulation of macroplastics in rivers, sea and beach, and as close to the source as possible, says Busch.

The group would like to get in touch with other environments that will contribute to the development work.

Liquid waste in Lake Java outside Jakarta, Indonesia. Photo: Børge E. Bentsen

Text: Børge E. Bentsen