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Optical Methods for Marine Litter detection (OPTIMAL)

Sentinel 2 - image courtesy of ESA

Completed project

Project start: September 2017  |  Project end: September 2018
Funder: European Space Agency
Principal Investigator: Dr Victor Martinez-Vicente
Other participants from PML: Dr James Clark, Dr Rory Donnelly, Professor Pennie Lindeque, Stefan Simis

Marine litter consists predominantly of plastics and is an increasing global concern because of its worldwide distribution and its impacts on the environment and, potentially, on human health. To be able to mitigate the problems that litter causes we need to understand the problem better.

Currently, data on plastics are taken from a limited number of sites, including the subtropical gyres of the northern hemisphere and various coastal monitoring sites. For large areas of the open ocean, including much of the southern hemisphere, equatorial regions, and higher latitudes in the northern hemisphere, there are little or no data. Data availability is also extremely limited in the economically important coastal ocean. It is vital that these data gaps are filled so that reliable budget estimates can be computed. Such an effort would help assess the current potential of harm caused to the marine environment, to guide monitoring efforts, and to act as a benchmark against which to judge the effectiveness of future management scenarios. Such potential harm includes the potential to negatively impact habitats and life cycles of a wide range of sea creatures, from micro zooplankton to turtles, as well as effects on human health through entry into the foodchain.

The OPTIMAL project will build upon existing work to monitor marine plastics by producing a plan for the development of a potential future detection and monitoring system targeted specifically to the remote detection of marine litter.

The main aims of the project are to:

  • Identify and characterise the critical applications potentially accessible to remote sensing.
  • Evaluate existing and planned sensor capabilities for detecting/quantifying marine litter.
  • Engage with the community of experts on marine litter (observationalists and modellers) and the remote sensing community in the process.
  • Define the activities necessary to utilitse current and foreseen sensors to detect marine litter, if existing; or define the characteristics of new sensors, if the existing ones are not considered capable to fulfil the science objectives.


The scientific community, regulators and society, in a wider sense, need a more detailed global picture of the plastic in the ocean. If a better estimate of marine plastic litter is obtained using remote sensing, this will have a significant impact in addressing both fundamental scientific questions as well as providing tools for environmental monitoring for the benefit of the society.