The Secret of Tetrodotoxin in Dutch Shellfish

Tetrodotoxin is a neurotoxin that can be harmful to humans at low concentrations. In the 2015-2016 season, TTX was found in shellfish in the Oosterschelde. There are many questions about the source, the measurability in organisms, toxicity, but also possible measures. Wageningen Marine Research is investigating these questions and supporting the sector and governments.

Tetrodotoxins (TTXs) are new toxins to the Netherlands. In 2015, TTX was found for the first time in shellfish from the Oosterschelde. Tetrodotoxin is a neurotoxin that can be harmful even at low concentrations. It can, for example, lead to paralysis. At high concentrations it is lethal for humans.

In 2016, the presence of TTX in mussels from the Oosterschelde led to the closure of several shellfish production areas just before the start of the mussel season. For the sector and the government, food safety is a top priority. That is why they are working together to take targeted measures that will guarantee food safety and fit in with commercial operations.

The objective of the research by Wageningen Marine Research into TTX is to guarantee the safety and availability of Dutch shellfish. The research is conducted in close cooperation with Wageningen Economic Research, Wageningen Bioveterinary Research and RIKILT.

The source of Tetrodotoxin is currently unknown. Initial research in 2016 provided some indications. Identifying the source and the environmental conditions to which the source responds is crucial for better predicting the presence of TTX and thus taking related measures by the shellfish sector. Given the (very likely) seasonality of TTX, concentrating research in the period in which TTX is found is essential.

Because very little is known about TTX, a high precautionary factor was applied in 2016 when setting standards. This is at odds with proportionality when it comes to socio-economic effects. The aim of the multi-year research programme is to arrive at an effective and efficient set of measures to guarantee food safety.

In order to enable the shellfish sector and authorities to be better prepared for problems such as TTX, the project will also develop a scenario which can be used as soon as a new acute problem arises (e.g. another new toxin or contaminant). By outlining scenarios, a more streamlined cooperation between government, industry and knowledge institutes can arise.

The knowledge gained in the programme is not only important for the Netherlands, but can also be used on a broader European scale.