Uncovering mechanisms inducing thiamine deficiency in top predatory fish

Thiamine (vitamin B1) dynamics and deficiencies of this vitamin are intensively discussed in the scientific literature and in media.

We need research to understand the mechanisms regulating the transfer of this micronutrient in the ecosystem and this information will guide management of the food webs to reduce this environmental issue.

Salmon in the Baltic Sea are periodically suffering from low reproductive output due to a thiamine deficiency syndrome called M74. Recent studies also suggest that cod is thiamine deficient.

Previous research on thiamine has generally used relatively low level of replication rarely comparing with non-affected populations and not using factorial setups disentangling mechanisms involved.

We will: 1) Quantify thiamine and thiamine degrading enzymes in cod, salmon and their prey items in a wide range of systems.

This will also provide data on the importance of gut microbiota for the production of thiamine degrading enzymes. 2) Disentangle if thiamin concentration and/or thiamin degrading enzymes govern the development of thiamine deficiency in top-predatory fish (mechanistic exp.). 3) Finally, develop a conceptual model on important mechanisms and bottlenecks involved in the transfer of thiamine from producers to top-predatory fish.

Cod and salmon populations are invaluable resources to our society e.g. for commercial and recreational fishing and we have already commenced communication with relevant stakeholders to prepare this application.