Neil Auchterlonie attended the Aquaculture Research Collaborative Hub UK (ARCH-UK)-organised workshop on microplastics in London on March 25th. ARCH-UK is an academia-led network of researchers and industry in the UK, which looks at a number of research priorities relevant to UK aquaculture. 

Discussions on the links between microplastics and health

What is relevant to the UK is also, in many if not most cases, also relevant to global aquaculture, and this event was no exception given the exposure the media has afforded this subject of plastics in the marine environment in recent months.  A well-managed event included a number of presentations from key researchers in the field, and extensive discussions focused on whether microplastics are dangerous to fish and shellfish ‘health’ and whether microplastics in fish and shellfish are of any risk to human health. Fishmeal was mentioned rarely during a whole day of discussions, but the researchers certainly consider marine ingredients in general to be a topic of interest. 

In summary, those discussions provided a good overall view of the current state of knowledge.

Human exposure to microplastics is via three routes

• Food: It appears that much of the work on food is disproportionately focused on seafood – there doesn’t seem to be too much yet on agriculture in the broader food context. Within seafood focus most of the effort is on aquaculture, specifically the filter-feeding bivalve molluscs such as mussels and oysters. Packaging for seafood seems to be regarded as a very important route of exposure and there was a lot of discussion about how to manage any risks attached to this link in the future.
• Drinking water as a route of exposure is significant (plastic water bottles, etc).
• Inhalation is also an important route of exposure, perhaps the most important at this stage.  Household dust has been reported as containing up to 33% MP.  Atmospheric fallout of plastics was mentioned, and a study in Paris was referred to which could perhaps have been the investigation behind this paper.

Limited knowledge on microplastics at this stage

At this stage the focus of efforts seems to be more on the directly consumed aquaculture product, but clearly the raw material for marine ingredients comes under consideration when viewing the total food chain and assessing risks overall.  Generally, although the topic of plastic in the marine environment is rapidly gaining traction in the global media, the science remains at a relatively early stage: “Very few scientific works have investigated the ecological effects of microplastics at population or species assemblage level in aquatic environments and hence there is limited knowledge on the capacity of microplastics to alter ecological processes, nor direct evidence of trophic transfer of microplastics in wild populations.” (FAO, 2019).

New measures to tackle plastic waste

In related news, readers may like to know that the European Union has just adopted new measures to tackle marine litter coming from the 10 single-use plastic products most often found on European beaches, as well as abandoned fishing gear and oxo-degradable plastics. According to the UN, about 8m tonnes of plastic waste is dumped in the seas annually.  

IFFO’s projects

IFFO will launch a research project in the coming months to support the membership with information that helps inform some knowledge gaps on microplastic impacts on fishmeal and fish oil production.  It will hopefully deliver some information that can help us understand better the implications for fisheries and aquaculture resources of this important topic. 

For further information, please check out the FAO's recent report about microplastics in fisheries and aquaculture.