Why monitor marine litter?
KIMO Denmark has been collaborating with DCE, The National Centre for Environment and Energy at Arhus University to monitor litter washed up on 5 Danish beaches. The work contributes data and knowledge which is used to inform Denmark’s Marine Strategy. The sea has no boundaries. This becomes abundantly clear when we begin to look at the objects that we find washed up on Danish coasts. European countries use the same protocol to monitor litter washed up on selected coastlines. OSPAR, the North Sea Regional Ocean Convention, has gathered data for years. Their dataset describes the number and nature of the objects that pollute our common marine environment and our coasts. Through monitoring, decision-makers can not only track changes in the composition, distribution and extent of marine litter but also gain feedback as to whether currently adopted measures are, in fact, working.
The Danish Marine Strategy from 2012 describes the state of Denmark’s marine areas, and sets goals for a future healthy marine environment. The strategy is part of the implementation of the EU Marine Framework Strategy Directive (Directive 2008/56 / EC of 17 June 2008).
The purpose of the directive is: “to maintain or establish so-called good environmental status in all European marine areas by 2020. The means of achieving this goal is the preparation of marine strategies with objectives for nature and the environment, monitoring programs and response programs. ”
The work carried out by KIMO and DCE for the Danish Environmental Protection Agency is part of the monitoring program that monitors waste on beaches for use by the Marine Strategy’s Descriptor 10 (Sub-program for marine waste). The current agreement on beach monitoring runs from 2019-2021 and aims to monitor the ‘evolution through time’ of the composition, distribution and (where possible) the sources of marine litter.
Monitoring Locations
The monitoring includes 5 selected reference beaches; Nymindegab, Skagen, Kofoeds Enge, Pomlenakke and Langerak beach. Geographically, the beaches cover the two major Danish seas, namely the North Sea/Skagerrak and the Baltic Sea. Langerak beach in the Limfjord near Aalborg represents the Kattegat area.
The selected beaches are considered to cover the variation between east and west. The beaches on the Jutland west coast receive some waste from foreign sources. Waste is led by water flows and comes from sources such as European rivers, shipping and fishing. The waste found at Langerak, which is near an urban centre, is estimated mainly to originate mainly from land. Kofoed’s meadows on Køge bay and Pomlenakke on Østfalster receive both Danish and foreign objects. Recreational activities are a major source of marine litter in the Baltic Sea.
Procedure
A reference area of 100 m has been designated on each of the 5 coastlines. By agreement with the relevant municipality, there is no beach cleaning in the area. Washed up litter is left to accumulate on the beaches between monitoring events. Monitoring on the beaches is done three times a year: spring, summer and autumn. Data is reported to the Danish Environmental Protection Agency and furthermore in a format that enables data to be reported annually for use by the regional marine conventions OSPAR and HELCOM. Data compilation is also comparable to previously collected beach data on the reference beaches.
Each item found on the reference area is collected and recorded for monitoring purposes. It can be a recognizable or indefinable object. The number is listed under the relevant category. The list is divided into 180 separate waste types, and is categorized as, plastic, rubber, textile, cardboard/paper, metal, wood, glass/ceramic or other. In Denmark, the collected data on marine litter will be used in 2020 to establish reference levels and inform interventions, with the aim of achieving significant reductions in 2025, compared with 2015.
Results
The most frequently found objects in Denmark have been:
- plastic fragments,
- string and cord under 1 cm,
- caps and lids,
- cotton bud sticks,
- candy wrappers,
- shotgun cartridges,
- balloons,
- straws,
- rope over 1 cm,
- food packaging,
- strapping bands,
- buoys/floats,
- toys and party poppers
- cigarette lighter,
- insulation foam
It can prove difficult to identify a particular source of pollution. Approximately half of the objects cannot be connected to a particular source. Bottles and other packaging may, for example, originate from a river as well as a ship. Most objects occur as fragments that cannot be determined with certainty. Research shows that worldwide, the majority of marine waste originates from sources on land. Known sources of marine litter are fishing, shipping, offshore industry, tourism, recreational activities, wastewater treatment plants, waste landfill, cities/households etc.
Plastic objects constitute the majority of the litter found on the beaches in Denmark. Plastic/polystyrene also constitutes 70% – 98% of the waste found in the North Atlantic sea areas. We can observe a higher prevalence of fishing-related waste such as nets, floats, gloves and fish boxes in the North Sea as compared to the Baltic Sea.
Efforts to stop marine waste

There are many challenges and a diverse array of interventions are required to curb the sources that contribute to litter in the world’s oceans. Through extensive European surveillance, several focus areas have been identified and this has contributed, among other things, to the design of the EU plastics strategy. In Denmark, targeted initiatives have been incorporated into the Danish plastic action plan. Denmark will support the EU Commission’s one-off plastic directive, will introduce a ban on non-degradable shotgun cartridges, will examine methods for cleaning up ghost networks and has already initiated measures to reduce carrier bag consumption. Other countries have introduced a ban on plastic cotton swabs and the introduction of deposit return schemes for plastic bottles. Efforts to combat marine waste require broad cooperation across borders. It is positive that Denmark prioritises the international commitment in this area. Monitoring of litter washed up contributes important knowledge to find sensible solutions.

