Pollution
The issue: Chemical pollution, toxic and solid residues and debris, including plastic, result from anthropogenic activities and the ocean is often the ultimate sink. There are numerous realised and potentially harmful effects of these pollutants, which vary depending on use and material. Major types of pollution include garbage, liquid chemicals, solid residues that make their way into the ocean through varied pathways including open dumping, spills, waste releases, natural disasters, hydroclimatological extreme events, shipping, industrial activities and from degrading debris (e.g. leaching from plastic or decomposing organic material). These direct and indirect coastal, riverine and atmospheric inputs vary from one region to another and are often greatest near the inflows (see Chapter 20, OMA). For example, nitrogen load from human activity into water ways was estimated at 32.6 MMT/yr (Mekonnen and Hoekstra 2015), and between 5 and 13 million tonnes of plastics (Jambeck et al 2015). Also, between 1990 and 1999 an estimated 6.8-5000 thousand tonnes of oil entered the ocean as run off alone (National Research Committee 2003). Assessing the impacts of these anthropogenic inputs (especially nutrient, sewage inputs from diffuse sources) and their combined effect is complicated (Jambeck et al 2020) and although impacts are evident in the deep sea few qualitative and accumulative studies are available (Ramirez-Llodra et al 2011).
The Working Group: The DOSI Pollution working group aims to 1) improve public understanding of and promote research into the patterns, impacts and relative risk of pollution and debris in the deep sea, 2) advocate for the consideration of deep-sea science in policy development and conservation initiatives, augmenting work already being done in shallow waters, 3) provide expert opinion on pollution and debris concerns through written responses, workshops, and engagement with pollution and debris-focused groups.
We are working to support the International Negotiating Committee (INC) on Plastic Pollution. For the Committee’s second meeting, held in 2023, we prepared a policy brief on the deep-ocean impacts of plastic pollution in both English and Spanish. You can read our Participation Report from the meeting here.
We plan to write further policy briefs on the following themes:
- Improved practice in fisheries to reduce fisheries-based marine litter
- Improved practice in merchant shipping sector to reduce shipping-based marine litter
- Why the knowledge on deep-sea contaminants is crucial in baseline environmental impact studies
- Developing a list of existing groups working on marine plastic pollution with which to engage, with the aim of adding the deep-sea perspective.
- Press pack, providing a unified expert opinion on the impacts of pollution and debris
- Development of a reference listing of benthic and pelagic studies about plastic/debris/pollution in the deep sea
- Discussion of the differing methods of assessing plastic in the marine environment, with the aim of developing best practices for the global community.
- Developing a matrix to help inform communities of relative risk of different deep sea threats, along with other WGs
2026
- Publication of report from UNOC3 Conference Side Event on “The UN Treaty to End Plastic Pollution: Robust Science for Success”, co-organised by DOSI.
- The Working Group contributed knowledge on the potential for contaminant release and ecotoxicology from mining activities, marine carbon dioxide removal approaches or offshore energy installations, to the workshop held in Glasgow on “Assessing Cumulative Impacts on Deep-sea Communities”, organised by the Climate Change Working Group.
- The Working Group was involved in the organisation, and several Working Group members participated in the online ICES Workshop on Deep Sea Mining Chemical Impacts, Thresholds, Monitoring, and Uncertainty (WKDSM), held on 17-18 March. Nélia Mestre delivered the talk on: Chemical exposure pathways, ecosystem responses and critical uncertainties relevant to environmental risk assessment. This will result in an ICES report that is currently being produced.
- Co-lead Nélia Mestre, participated in the annual meeting of the ICES Marine Chemistry Working Group, hosted at the Instituto Hidrográfico in Lisbon, from 20-24 April. Many topics were discussed, and work will
continue during the year to produce policy-relevant documents related to chemical substances of emerging concern (including their presence in the deep sea), microplastics and ocean acidification, as well as human impacts derived from renewable energy and deep-sea mining. Important documents are regularly produced by the group and used by policymakers for improved management towards a healthier and more resilient marine environment. Many members of the ICES Marine Chemistry Working Group are now members of the DOSI Pollution and Debris Working Group as a result. - Lucy Woodall, Melanie Bergmann and Chris Pham attended the International Seafloor Macrolitter workshop 2026 in Athens, Greece. This is an invited group of global experts that discussed issues on pollution of the ocean by seafloor macro-litter, including monitoring, data management and mitigation
measures.
2025
- The Working Group participated in the workshop on “Process for Improving Knowledge of
the Deep Sea Offshore Energy in Colombia: A Framework for Science, Industry, and Policy”, organised by the
Offshore Energy Working Group. There, a perspective on the contaminants that can be released from the
installation of offshore energy structures was highlighted.
2021
- 8 September 2021 – public webinar hosted by DOSI Pollution & Debris working group
- 29 March 2021 – written submission to the Office of the High Commissioner on Human Rights on deep-ocean marine plastics (a rights-based approach to life cycle of plastics).
2020 and earlier
- Canals, M., Pham, C.K., Bergmann, M., Gutow, L., Hanke, G., van Sebille, E., 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., Möller, T., Nattkemper, T.W., Ruiz, M., Suikkanen, S., Woodall, L.C., Fakiris, E., Jack, M.E.M., Giorgetti, A., 2020. The quest for seafloor macrolitter: a critical review of background knowledge, current methods and future prospects. Environmental Research Letters.
- Jambeck, J.R. et al 2020. Blue Paper 5: Leveraging Multi-Target Strategies to Address Plastic Pollution in the Context of an Already Stressed Ocean. High level panel for sustainable ocean economy. World Resources Institute
- Human footprint in the abyss: 30 year records of deep-sea plastic debris (Chiba et al. 2018)
- Jambeck, J.R., et al. 2015. Plastic Waste Inputs from Land into the Ocean. Science 347 (6223): 768–71.
- Mekonnen, M.M. & A.Y. Hoekstra. 2015. Global Gray Water Footprint and Water Pollution Levels Related to Anthropogenic Nitrogen Loads to Fresh Water. Environmental Science & Technology 49 (21): 12860–68.
- Ramirez-Llodra, E., et al 2011. Man and the last great wilderness: human impact on the deep sea. PLoS one, 6(8) e22588.
- National Research Committee. 2003. Oil in the Sea III Inputs, Fates, and Effects, National Research Council of The National Academies.
-
Collaborate with us to advance deep-sea climate science. Engage in meetings, contribute to policy briefs and publications, and participate in international events.
WG members are encouraged to actively engage with WG communications and meetings, as these are where further information will be provided on workshops, outputs such as policy briefs and publications, as well as event attendance. Please note: DOSI Ambassadors who are involved key meetings are selected according to our DOSI internal policy and at the discretion of the WG leads.
Working Group Leads
Lucy Woodall
University of Oxford, UK
Nélia Mestre
University of Algarve, Portugal