How many marine litter lies at the sea floor?


 (c) Thünen Institut

Monitoring of macro litter at the sea floor

A soda can lying at the beach and a plastic bag floating at the surface are visible for everybody. But the major part of marine litter sinks to the sea floor someday and is concealed. How many and which kind of litter is lying there is investigated by the Thünen-Institute using litter in fishery catches.

Background and Objective

Marine litter has become a subject of major concern in recent times. Globally, huge amounts of man-made solid waste materials end up in the oceans coming from both land - and sea-based sources. Levels of marine litter at the seafloor are presumed to be rising with the increasing global population densities and industrial production.

Plastic waste materials are of special concern, as plastic items are highly persistent and compose the dominating category of marine litter. Plastic debris can pose a risk to the marine environment, by causing physical damage in marine organisms via ingestion or entanglement and also due to potential toxic effects .

In Europe marine litter was recognized as major risc factor for the marine environment and consequently included as one of eleven qualitative descriptors for the "good environmental status" in the Marine Strategy Framework Directive (MSFD). The MSFD schedules monitoring programmes for the assessing the status of the marine ecosysteme. Studies on marine litter are often based on an international agreed protocols (e.g. ICES International Bottom Trawl Survey IBTS), for standardized recording of marine macro litter (>2,5cm).

The aim of the project is to record the amount and composition of marine litter at the sea floor to (1) evaluate the status of the ecosysteme and to (2) better understand the dynamic of litter in the sea.


Macrolitter in bottom trawl fishery catches are regularly monitored and categorized according to IBTS. Each litter item catched is photographed.

The amount of litter is given in litter items per km² area covered by the trawl .

Our Research Questions

  • How much litter are present at the sea floor of Northsea and Baltic Sea?
  • Are there regional differences in amount and composition?
  • How does the amount of marine litter changes in time?
  • Which threats for fish and ecosysteme are caused by marine litter?

Preliminary Results

First results on composition of litter at the sea floor can be found HERE.

Links and Downloads


Involved Thünen-Partners


Permanent task 12.1987 - 12.2023

More Information

Projekt type:
Project status: ongoing


hits: 2

  1. Canals M, Pham CK, Bergmann M, Gutow L, Hanke G, Sebille E van, Angiolillo M, Buhl-Mortensen L, Cau A, Ioakeimidis C, Kammann U, Lundsten L, Papatheodorou G, Purser A, Sanchez-Vidal A, Schulz M, Vinci M, Chiba S, Galgani F, Langenkämper D, et al (2021) The quest for seafloor macrolitter: a critical review of background knowledge, current methods and future prospects. Environ Res Lett 16(2):023001, DOI:10.1088/1748-9326/abc6d4
    pdf document (limited accessibility) 3335 kb
  2. Kammann U, Aust M-O, Bahl H, Lang T (2018) Marine litter at the seafloor - abundance and composition in the North Sea and the Baltic Sea. Mar Pollut Bull 127:774-780, DOI:10.1016/j.marpolbul.2017.09.051