Tackling marine litter and microplastics with the Dr Fridtjof Nansen
The rapid rise of plastic and issues with waste management systems have become major global problems in recent decades, especially for the ocean. In fact, marine debris, also called litter, which consists of any persistent, manufactured or processed solid material discarded, disposed of, or abandoned in the marine and coastal environment as a result of human activity, is described as one of the major threats to marine and coastal biodiversity in recent high-profile publications. Today, we know that plastics are found in every part of the ocean, including the surface, water column and the deepest ocean troughs, from the Arctic to the Antarctic – but what are the impacts? The EAF-Nansen Programme is dedicating resources to evaluate the presence and risks of marine litter and microplastics in the ocean, using the research vessel Dr Fridtjof Nansen.
It is estimated that between 60 to 80 percent of marine litter is composed of plastic, according to the ocean health index. In 2016, a study suggested that there were around 19 to 23 million metric tonnes of plastic waste in the ocean. This large quantity of marine litter and microplastics (particles < 5mm in diameter) is causing significant social, economic and environmental impacts, including in the fisheries and aquaculture sectors.
“We know that urgent action is required to reduce the leakage of plastics to the ocean, but there is no simple solution,” says Dr Peter Kershaw, expert on marine litter and microplastics at FAO. “To design more effective mitigation measures, we need more information on the sources, quantities and types of litter, especially from regions and countries where data are lacking. With more knowledge, we will also be able to estimate the risk to local communities in terms of health, key economic sectors as fisheries, as well as to the environment more generally”, Dr Kershaw states.
To provide insights, the EAF-Nansen Programme is using data and observations from surveys carried out by the Dr Fridtjof Nansen. From 2017 to 2019, this state-of-the-art vessel has conducted surveys off the coast of West and East Africa and in the coastal waters of countries in the Bay of Bengal, as well as a transect survey of the Indian Ocean. During these surveys, sampling of marine litter and microplastics from surface waters, sediments and selected fish or invertebrate species took place.
A series of publications is in development, based both on existing results and on the expected outcome of surveys planned in 2021 and 2022, and a Policy Brief will be prepared. The processing and identification of microplastics requires quite sophisticated analytical facilities. It is planned to develop this capacity in some partner countries, but in the meantime analyses are carried out at the laboratories at the Institute of Marine Research (IMR), in Norway.
“We are currently analysing samples from surveys carried out by the Dr Fridtjof Nansen in the Bay of Bengal in 2018, in the proximity of Sri Lanka, Myanmar and Thailand”, says Bjørn Einar Grøsvik, research scientist at IMR. “A team of scientists from the countries and IMR are working together to present the findings in an upcoming paper titled “Spatial distribution of microplastics in surface waters in the Bay of Bengal”, in which we aim to describe the occurrence and distribution of microplastics in the surface water in the Bay of Bengal, to map and identify areas with high concentrations of microplastics, and explain differences by use of oceanographic models”, Dr Grøsvik further explains.
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| Agnethe Herztberg from her presentation from the course on how to analyse polymer type of plastics by ATR FTIR. © IMR/Bjørn Einar Grøsvik | Sample of microplastics from survey in the Bay of Bengal in 2018. © IMR/Bjørn Einar Grøsvik |
In addition to the research efforts, the Programme is organising a series of training courses. One of these courses took places on 22-23 June, inviting co-authors of ongoing publications to discuss the subject and learn more about the sampling and analytical methods for microplastics in environmental samples.
Participants Dr Moulaye Mohamed Wagne from the Mauritania Institute of Oceanographic Research and Fisheries and Ms Pooja Solanki from the Tanzania Tuna Fishery National Alliance found the training useful and relevant due to the pressing need to take action against marine litter. “This is an emerging problem, and it is urgent for us to investigate this issue given the health and environmental risks at stake for a country like Mauritania,” said Dr Wagne, while Ms Solanki stated that: "Microplastics are toxic materials that has invaded the marine environment, and urgent measures are required to detoxify it."
Activities are also planned for the Gulf of Guinea, where the EAF-Nansen Programme is collaborating with four member countries – Togo, Benin, Ghana and Côte d'Ivoire – to gather information on the impact of marine litter on local fishing communities.
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| Contents of a demersal trawl off Ghana, 2019. © IMR/Tor Magne Ensrud | Litter on a beach in Senegal composed of a wide variety of materials, including plastic, rubber and fabric. © IFREMER |
In Ghana, the field survey is already underway, and findings are illustrating how marine litter has become a significant part of the daily lives of fishermen in the Volta region. “Not only do they catch high quantities of waste along with their fish, which increases the time spent sorting the fish and reduces the value of their catches that are already declining, the litter sometimes destroys the gear and causes injuries to the fisherfolk sorting as well”, said Sika Abrokwah, a research fellow from the University of Cape Coast, who is leading the study in Ghana.
Once the study has been completed, results will be used to support the development of policies and management practices needed to tackle the issue in these countries.
Useful links
- FAOs work on climate change – Fisheries & aquaculture 2019 (FAO Publication)
- Microplastics in fisheries and aquaculture – Status of knowledge on their occurrence and implications for aquatic organisms and food safety (FAO publication)
- FAO on Abandoned, Lost or otherwise Discarded Fishing Gear (ALDFG) (FAO Website)
- Marine Debris: Understanding, Preventing and Mitigating the Significant Adverse Impacts on Marine and Coastal Biodiversity (Report by the Convention on Biological Diversity)
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