Fourth version of "From Land to Sea"

Fourth version of "From Land to Sea"


The model developed on behalf of the BKV entitled "From Land to Sea – Model for the documentation of land-sourced plastic litter" has been updated and further developed on the basis of fresh data and new facts. In the present fourth version, there is also an important innovation: The report additionally contains for the first time data on the "input quantities" into the discharge sources. Apart from that, volume estimates of tyre abrasion are also shown for the first time.

Research on marine litter is always coming up with fresh findings and above all new data. The model "From Land to Sea – Model for the documentation of land-sourced plastic litter", which was initially developed seven years ago, therefore has to be constantly revised and updated. The fourth version of the model, including the handbook, has now been published after having been adapted to reflect the current state of knowledge – above all in terms of the data.

The fourth edition also brings an important innovation: Until now, the model stated only the discharge volumes of improperly disposed-of plastic waste that was attributable to Germany and ended up in the North Sea, Baltic Sea or Black Sea via the four main discharge pathways and sources – rivers, coasts, shipping and ports. Now, the report also contains information on the "input quantities" into the discharge pathways and sources. These "input quantities" illustrate how much of the improperly disposed-of plastic litter ends up in the discharge pathways and sources named in the model. This makes it possible to better understand the calculations made in the model, particularly as the transfer and loss factors that are taken as a basis for the respective discharge pathways or sources are also still described. The transfer and loss factors form the mathematical corrective, which considers the fact that not all the plastic waste discharged into a discharge pathway actually ends up in the sea.

Also new is that the results from the tyre abrasion study have also been included in the report on the model. They are listed separately from the quantities of macroplastics and microplastics. The reason for this is the official definition: The main component of a tyre is rubber and thus not plastic. In the research on the topic of marine litter, however, tyre abrasion is nearly always assigned to microplastics. Against this background, the authors of the BKV model tackled the topic in a separate report.
The results have now been included in the model.

We now get the following picture for the annual discharges from Germany into the North Sea, Baltic Sea and Black Sea:

  • microplastics account for approx. 60 t,
  • macroplastics account for approx. 1,700 t and, additionally,
  • tyre abrasion accounts for approx. 5,000 t.

Compared with earlier versions of the report, the figures for microplastics and macroplastics have changed somewhat, mainly due to the improved data situation, which enabled more valid calculations during the course of the last update. Thus the total discharge of microplastics into the seas has fallen, whereas the total discharge of macroplastics has increased.

The results of the other special reports have also been included in the model calculations, namely on the topics of "littering" and "composts and digestates".

In an interview in this newsletter, one of the authors of the study and managing director of Conversio GmbH, Christoph Lindner, explains additional background information on the fourth version of the study "From Land to Sea".

The report and handbook on the model as well as the relevant special reports can be ordered free of charge at www.bkv-gmbh/infothek/studien (the fourth version is at present only available in German).

Your contact partner for these topics is Stephanie Cieplik (stephanie.cieplik(at)

Photo: © BKV / Barretto

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