Deep Dive into the Plastic Sea

The results from the deep dive into the plastic sea reveal significant regional variations in the composition of marine waste.

Along the coastline, products related to the fishing and aquaculture industry, as well as other marine activities, constitute a substantial portion of the waste. In Norway’s most densely populated areas, consumer-related waste comprises the largest proportion.

Mepex, in collaboration with Hold Norge Rent, Asker Municipality, Orkla, Infinitum, and visual artist Pippip Ferner, secured funding from the Norwegian Environment Agency to gather more knowledge about marine waste.

Mepex developed a model for in-depth laboratory analysis and a simplified version for field use. Using these models, close to 10 tons of marine waste from 50 different cleanup actions along the entire Norwegian coast were analysed. In addition to weight and quantity, data on source, age, material type, geographical origin, and photographs of all products were recorded.

Fishing and aquaculture industry tops the lists by weight, EPS by quantity

The deep dive resulted in a robust knowledge base. By registering both weight and quantity at the product level, it provided a nuanced and diverse picture of the composition of plastic in the sea.

The results show that the majority of marine waste is plastic. Looking at weight, 73.5% of the waste is plastic, and a whopping 91.5% if we consider quantity. Examining the top ten list based on quantity, expanded polystyrene (EPS) ranks highest. When looking at weight, the most significant portion consists of equipment and products related to the fishing and aquaculture industry and other marine activities. The top ten list based on quantity also indicates far more consumer-related waste compared to the list based on weight.

Period: 2019 – 2020 Team:
Tallak Syversen, Jonathan Wegger
Main contact: Kathrine Kirkevaag Relevant documents:

Half of the waste is under 5 years old

Among the analysed waste, the age of 5% of the products has been identified. Within this 5%, the results indicate that 49% are under 5 years old, 35% are between 5-15 years old, and 16% are over 15 years old. This implies that we are still cleaning up “old sins,” but there is also a portion of waste that is relatively new.

The products with the easiest age identification are packaging, especially food packaging and household bottles marked with production or expiration dates. Looking at the age of drink bottles, nearly 60% of the bottles are over 5 years old.

Geographical origin registered for 10% of the waste

The geographical origin was recorded for 10% of the analysed waste. Of the waste with identified geographical origin, 77% comes from Norway. Foreign waste mainly originates from the United Kingdom, Denmark, and Sweden. In the north, waste from Russia is more prominent than in the south. Waste from Sweden is more prevalent in the south and on the west coast.

Wish to dive deeper into the project?

Consult our advisor Kathrine Kirkevaag
Kathrine Kirkevaag
Kathrine Kirkevaag Team lead – Circular solutions +47 901 54 786 |