How many marine litter lies at the sea floor?

Background and Objective

Marine litter has become a subject of major concern. 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. Surveys uses international agreed protocols (ICES), for standardized recording of marine macro litter (>2,5cm).

Approach

Macrolitter in bottom trawl fishery catches are regularly monitored and categorized according to ICES.
The amount of litter is given in litter items per km² area covered by the trawl.

Data and Methods

Every litter item collected on board is weighed, photographed and categorized according to IBTS. Platic litter items were taken to the lab to determine polymer composition using FTIR spectroscopy.

Links and Downloads

www.thuenen.de/media/publikationen/thuenen-a-la-carte/ThuenenAlacarte13.pdf