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MARINFORSK-Marine ressurser og miljø

Toxic microalgae in Norwegian waters (ToxANoWa): Uncovering fish-killing mechanisms of phytoplankton from Scandinavian waters

Alternative title: Giftige mikroalger i norskehavet: Mekanismer for fiskedød forårsaket av fytoplankton fra skandinaviske farvann

Awarded: NOK 12.0 mill.

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2021 - 2025


Algal blooms are seasonal phenomena in marine and freshwater ecosystems, and their frequency and severity are increasing. Algal blooms may be harmful (so-called HABs) and result in the die-off of vertebrate and invertebrate species. The ToxANoWa project is inspired by the recent HAB event that occurred in Northern Norway during the spring 2019. The responsible species for the toxicity of the bloom has been identified as Chrysochromulina leadbeateri, and collaborators are in possession of both field samples and laboratory cultures of this algal species. Very little is known about why this species may be toxic to fish. ToxANoWa aims to shed light on this by bringing together researchers with backgrounds in marine biology, toxin chemistry and toxicology. The project also aims to study species in the related genus Prymnesium, which were historically responsible for HABs 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. P. parvum grows in many regions worldwide, but the chemistry and toxicology of the prymnesins is still not well understood. ToxANoWa aims to produce selected prymnesins so they are available for research and monitoring purposes. In addition, the ToxANoWa team will make efforts to raise prymnesin antibodies that may be used to develop research and monitoring tools to simplify selective extraction and detection of these toxic chemicals. Another Prymnesium species is P. polylepis, which was responsible for a large and toxic bloom in the Kattegat and Skagerrak in 1988. It is still unknown why this species is harmful to fish, but application of the modern technologies in ToxANoWa will hopefully provide additional clues. This project is a collaboration between the Norwegian Veterinary Institute, University of Oslo, the Technical University of Denmark and the National Research Council of Canada.

Researchers currently observe an increase in the frequency, severity and geographic distribution of harmful algal blooms all over the world. Scandinavia is no exception, and the recent toxic algal bloom in Northern Norway during spring 2019 was disastrous for the aquaculture industry resulting in total lost production of about 40,000 tons of salmon, equating to financial losses estimated at around NOK 2.2 billion (USD 225 million). Despite the regular and worldwide occurrence of fish-killing algal blooms, the exact mode-of-action of many relevant species remains unclear. The ToxANoWa project aims to obtain a comprehensive understanding of the fish-killing activity and mechanisms of selected and relevant bloom-forming species from Scandinavian coastal waters, and to identify climatic and anthropogenic factors that affect toxicity. By combining a suite of bioassays with state-of-the-art chemical profiling and analyses we will identify potentially toxic compounds in algal cultures and a field sample from the 2019 algal bloom in Northern Norway. One of the few types of algal toxins that is known for their fish-killing toxicity are the prymnesins. This class of toxins will receive special attention, and we wish to study their structural diversity and toxicity in Scandinavian algal strains in detail. The ToxANoWa project will also result in technological advancements, and for the first time provide the scientific community with prymnesin reference standards and antibodies for future worldwide monitoring efforts.


MARINFORSK-Marine ressurser og miljø