Technologies for Observing and Monitoring Plastics in the Oceans

Massive and rapidly increasing use of plastics in modern society with short average use times and poor reuse and recycling options has resulted in a global threat with potentially devastating impacts on human and non-human life. Knowledge on the impacts of plastics in all forms on the planetary life-support system is rapidly accumulating and it underlines the scale of the risk humanity is taking. While quantitative information on production and use of plastics is to a large extent available, the fate of plastics discarded or leaked into the environment is highly uncertain. In particular, knowledge of how much plastic at different scales down to micro and nano levels reaches the ocean and the trajectories of the plastic in the ocean remain poorly known. Based on the mounting evidence, the United Nations have recognized the threat and are coordinating the many efforts to limit the amount of plastic that enters the environment uncontrolled. However, the Earth observation community so far has not managed to establish a global tracking and information system that would provide quantitative information on where and how plastics move in the ocean and allow the identification of the points where marine plastic pollution could be reduced most effectively. There are a number of independent projects focused on better monitoring plastics in the environment, including the ocean. In particular, projects in the EU, USA, and Japan have participated in working groups initiated by UN Environment. These projects are focusing on the monitoring of marine litter and plastics, management of information and knowledge, risks assessments, exploitation of opportunities and synergies, and, as far as possible, estimation of relevant costs and benefits. Measurements proposed include satellite and airborne remote sensing, surface and underwater in situ measurements, and crowd-sourcing observations. The need for extensive data processing and the use of deep learning techniques is acknowledged. The sensors considered range from multi- and hyperspectral sensing or other optical sensing to radar imaging aiming at a wide geo-spatial coverage. There is a need to develop global coordination mechanisms to ensure that societal knowledge needs are met and decisions on reducing plastic pollution in the ocean are informed by this knowledge. OES in collaboration with the Blue Planet Initiative of the Group on Earth Observations (GEO) and the UN environment, is leading an initiative aiming at this coordination.