Launch of new Litterbase: distribution and biological effects of marine litter

A unique global approach to display essential information drawn from all scientific publications on marine litter since 1960.

The launch of this litter database (litterbase.org) by the Alfred-Wegener-Institute for Polar and Marine Research is the first of its kind worldwide. For the first time, all scientific studies published between 1960 – 2017 dealing specifically with litter in the marine environment, have been screened and essential parts of their content graphically displayed. This unique database allows a worldwide insight into the research landscape about marine pollution and delivers crucial information for decision-makers. A world map shows where litter quantities as well as interactions of species with litter have been studied. The main focus is on: What kind of interaction between aquatic life and marine litter has been examined by scientists and where? And secondly: What is known about the amount and distribution of litter and microplastic?

It is a huge achievement to systematically categorise scientific publications and make essential parts of their content easily available. Scientists of the Alfred-Wegener-Institute for Polar Research (AWI) have looked into every single study and determined the interaction type. They evaluated whether the study deals with the entanglement of species in litter, whether it analyses the colonisation of marine litter by species or the ingestion of garbage. A number of species colonises floating garbage, thus enabling them of reaching areas well beyond their natural area of distribution. Unknown are the potential impacts for ecosystems.

Beside the specific biological impacts, the litterbase provides information on total amount of litter found in scientific studies. The information on display can be filtered according to size category of the litter (macro: > 5 mm, micro: ≤ 5 mm, nano: ≤ 100 nm) and according to marine realms (beach, sea surface, water column, seabed). Users can select subsets of data with the same unit for direct comparison in addition to global maps with all litter quantities. This tool is especially valuable since comparing results is of paramount importance, and often impossible if units differ.

The litterbase map shows that a fair number of interactions was recorded from the Atlantic, Mediterranean and North Pacific.  Interactions were defined as contact of a species with litter (see above): entanglement, colonisation or ingestion. Some interaction may even be fatal. Only few encounters were reported from other regions, for example, from the Indian Ocean and Polar Regions. These regions are still fairly unknown scientific territory.

The distribution map shows that litter quantities vary strongly within certain regions, e.g. in the Southwest Pacific and East Asia. Little is unfortunately still known about litter pollution in the tropics, around Africa or the Polar Regions. Plastics accounted for the bulk of litter in most realms of the ocean. On average 68 - 85 % of the litter was composed of plastics.

Figures complement the litterbase. They give an overview of the known effects that a litter encounter has on aquatic life (on breathing/oxygen uptake, growth etc.), or the species groups affected by litter. The figures specify the average composition of detected litter in different marine realms. Microplastic pollution can be separately displayed. The current analysis has shown that large amounts of resin pellets dominate on the beach and seafloor. Resin pellets are the raw material, from which plastic products are made. They are often lost during transport or manufacturing. Small fragments of plastics and Styrofoam dominate microplastics at the sea surface and in the water column.The litterbase provides links to every stated scientific publication, thus making it easy for users to deepen their understanding of this global environmental issue. It is continuously updated and content of new publications visualised in maps. This new database is a unique tool. It assists researchers, decision makers, media and anyone interested in this issue likewise. It delivers for some regions of the world exact data about litter quantities and its distribution and allows profound insight into research of vulnerable species. 

The AWI-Litterbase has been funded by Helmholtz Earth System Knowledge Platform (ESKP). On ESKP, eight centre of Helmholtz Association communicate background information on natural hazards, climate change, pollution and sustainable energies 

Translation: Jana Kandarr (ESKP), Press release AWI

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