Algal blooms occur naturally in a seasonal pattern in oceans and freshwater. The frequency, and to some extent the extent, of algal blooms is thought to be at least partly due to human impact. Such algal blooms can be harmful to aquatic life and lead to mass mortality of fish and other animals. The ToxANoWa project is a direct result of the toxic algal bloom in Northern Norway in the spring of 2019, which was catastrophic for the aquaculture industry and resulted in the death of around 40,000 tons of salmon. The bloom was dominated by the species Chrysochromulina leadbeateri, and the partners in ToxANoWa are in possession of both field samples and laboratory cultures of this algae species and have begun work to investigate these samples. Until now, very little has been known about why this species is toxic to fish. ToxANoWa aims to shed light on why this species is toxic to fish by bringing together scientists with backgrounds in marine biology, analytical chemistry and toxicology. The use of RTgill-W1 gill cells in testing fractions from purification has led to the isolation of a polyketide-derived compound from the toxic fractions. This compound has now also been detected in an older strain of C. leadbeateri from a previous HAB event and in water samples collected from the toxic bloom in 2019. Work is currently underway to confirm the toxicity of this compound and to determine its chemical structure.
The project is also studying species in the related genus Prymnesium, which has historically been dominant in toxic algal blooms in Scandinavian waters. One of the species, P. parvum, is known to produce chemicals that are highly toxic to fish - these are known as prymnesins. Prymnesium parvum occurs virtually all over the world, most recently causing massive fish kills in the Oder River in Poland and Germany in 2022. The chemistry and toxicology of the prymnesins is still not well understood. The ToxANoWa team is working on producing selected prymnesins from algal cultures to make them available for research and monitoring purposes. The team is also currently investigating the chemical structures of C-type prymnesins. This is a new variant of prymnesin, which was recently discovered by ToxANoWa collaborators. In addition, the ToxANoWa team is working on creating a suitable antigen for making prymnesin antibodies that can later be used for the production of sensitive immunological analysis tools. It is still unknown why this species is harmful to fish, but the use of modern technology in ToxANoWa is expected to contribute knowledge about this as well.
Project partners
- University of Oslo
- the Technical University of Denmark
- National Research Council of Canada
