The Mystery of the Disappearing Mussels
The mussel population in Norway has declined, possibly due to pollution, diseases, invasive species, and climate change. Tralopyril, a biocidal agent, has been detected in mussels and may have toxic effects. Monitoring tralopyril is essential to assess its impact on marine ecosystems and food safety. Limits for substances in food are necessary, and sensitive and accurate analytical methods must be made available.
The Mystery of Norway's Disappearing Mussels
The mussel population in Norway has seen significant changes in recent years, with reports of declines along the coast. The Institute of Marine Research has received concerns about the disappearance of mussels from areas where they were once common.
Possible explanations include pollution from aquaculture, especially delousing agents, which can leak into seawater and harm marine organisms.
High mortality rates in mussels may also be linked to diseases caused by bacteria like Vibrio spp. or competition from invasive species, such as the Pacific oyster, which displaces mussels from their natural habitat.
Climate change, such as rising water temperatures and ocean acidification, may further impact mussel growth and reproduction.
To better understand these changes, the Institute of Marine Research has initiated mussel population monitoring, which will provide important information on their status and the factors affecting them.
Tralopyril Detected in Mussels and Fish
A chemical recently detected in both fish and mussels is tralopyril, a substance used in biocidal products, particularly antifouling agents. Antifouling agents are chemicals used to prevent the growth of organisms like algae, mussels, and other marine life on surfaces such as ship hulls, underwater structures, and fish farming equipment. This discovery raises questions about potential toxic effects on marine organisms and could contribute to the observed changes in the mussel population. Monitoring tralopyril in marine habitats will be crucial to assessing its impact on both mussels and the marine ecosystem as a whole.
Tralopyril
Tralopyril, with the chemical formula C₁₂H₅BrClF₃N₂ and a molar mass of 349.53 g/mol, is a pyrrole compound and an active ingredient in biocidal products, particularly antifouling agents. It is classified as an organochlorine and organofluorine, which provides specific properties to combat the growth of unwanted organisms, such as algae and mussels, on fish farm nets.
Tralopyril Usage in Norway
In Norway, the use of tralopyril has significantly increased since it was approved by EU regulations in 2014 as a replacement for copper, which had previously been the dominant substance for treating aquaculture nets. The increased use of tralopyril has been driven by concerns over copper’s environmental impact, which can harm marine ecosystems when released from aquaculture facilities.
Regulations: EU and Norway
EU regulations for biocidal products are set through Regulation (EU) No 528/2012, governing the availability and use of biocidal products. Tralopyril was approved as an active substance in 2014, with specific requirements for safety, use, and monitoring to ensure that products meet health and environmental standards.
In Norway, these regulations are enforced by the Norwegian Food Safety Authority and the Norwegian Environment Agency, responsible for monitoring the use and content of chemicals in food and water. It is essential that products containing tralopyril do not exceed maximum residue limits in food, as regulated by Regulation (EC) No 396/2005, which establishes pesticide residue limits in food and feed to protect consumer health.
Media Coverage and Toxicity Concerns
There has been increasing media concern about tralopyril's effects on the environment and human health. Researchers, like Bjørn Einar Grøsvik, have expressed concern that the rapid adoption of tralopyril could result in substituting one harmful substance with another. Reports indicate that tralopyril can accumulate in marine organisms and has the potential to negatively impact ecosystems.
Studies have indicated that tralopyril breakdown products, such as trifluoroacetate, belong to the perfluorinated compounds (PFAS) group, known for their toxicity and ability to bioaccumulate in the food chain. This has led researchers to call for more thorough testing and monitoring of tralopyril in the environment.
A recent report from the Institute of Marine Research analyzed the uptake and degradation of tralopyril in salmon exposed to tralopyril-coated fish farm nets. Tralopyril, also known as ECONEA, has become increasingly popular as an antifouling agent in Norwegian aquaculture, especially following a reduction in the use of copper (Cu₂O) due to environmental concerns. In 2022, 98 tons of tralopyril were used in Norway.
The study, conducted in a controlled laboratory, kept salmon in tanks with tralopyril-coated nets for 30 days. Results showed that tralopyril was measured in both muscle tissue and feces from the salmon, with levels above the quantification limit (LOQ) in a high percentage of samples. Bioaccumulation in salmon muscle was significant, indicating that tralopyril may have a potentially negative impact on food safety.
Further, tralopyril breakdown products, such as HTFCCP, were found in both liver and feces. No maximum residue limits (MRLs) are currently set for tralopyril, making risk assessment challenging. The report underscores the need to establish MRLs and assess the risks associated with tralopyril use in aquaculture.
The Importance of Setting Limits
Establishing limits for tralopyril in food is crucial to protecting public health. Setting maximum residue levels (MRLs) is necessary to prevent harmful effects of toxic substances in food products. Without clear limits, health issues may arise, particularly for vulnerable groups such as children and pregnant women, who are more susceptible to the effects of such substances.
Methods for Measuring Tralopyril
Vitas is developing highly sensitive LC-MS/MS methods for measuring tralopyril in various sample types, including fish, mussels, seawater, and sediment. By implementing these advanced analytical techniques, we aim to contribute to a better understanding of tralopyril's prevalence in marine environments and its potential effects on ecosystems.
Through our analyses of tralopyril in various sample types, we can gather valuable information on the levels of this substance in seafood and marine habitats. This will not only support risk assessment but also the development of guidelines for maximum residue limits (MRLs) in food, which are essential to protect consumer health.
With our methods, Vitas hopes to uncover hidden issues related to tralopyril, thereby promoting sustainable aquaculture and ensuring that the food produced is safe for consumption. This work will also align with current EU regulations and national guidelines focused on monitoring chemical substances in the environment.
Contact us if you have projects related to this topic and require analytical services, including tralopyril and related compounds.
References
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Havforskningsinstituttet. (2024). "Analysis of uptake of tralopyril and transformation products in salmon exposed to tralopyril coated net pen." Rapport fra Havforskningen.
European Commission. (2014). "Commission implementing Regulation (EU) No 1091/2014." Official Journal of the European Union.
EFSA (European Food Safety Authority). (2023). "Targeted review of maximum residue levels (MRLs) for chlorfenapyr." EFSA Journal.
Grøsvik, B. E., Ghebretnsae, D. B., Mortensen, S., & Sævik, P. N. (2022). "Kunnskapsstøtte om miljøeffekter av kobber. Delrapport I." Rapport fra Havforskningen 2022-50.
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Dahllof, I., Grunnet, K., Haller, R., Hjorth, M., Maraldo, K., & Petersen, D. M. (2005). "Analysis, Fate and Toxicity of Zinc- and Copper Pyrithione in the Marine Environment." TemaNord 2005:550. Nordic Council of Ministers.
European Commission. (2005). "Regulation (EC) No 396/2005 of the European Parliament and of the Council." Official Journal of the European Union.