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MARINFORSKHAV-Marine ressurser og miljø - havmiljø

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.

Project Number:

314861

Application Type:

Project Period:

2021 - 2025

Partner countries:

Algal blooms are seasonal phenomena in marine and freshwater ecosystems, and their frequency and severity are increasing. Harmful algal blooms (HABs) can kill vertebrate and invertebrate species. The ToxANoWa project was inspired by the recent HAB event that occurred in Northern Norway during the spring of 2019, with catastrophic consequences for the local salmon farming industry, in which 40,000 tonnes of farmed salmon died. The species responsible 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 and have started to investigate these samples. Until now, very little was known about why this species was toxic to fish. By bringing together researchers with backgrounds in marine biology, analytical chemistry and toxicology, ToxANoWa has begun to shed light on this. Bioassay-guided fractionation using RTgill-W1 gill cells has lead 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 an earlier HAB event and in water 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 responsible for HABs in Scandinavian waters. One of the species, P. parvum, is known to produce chemicals known as prymnesins that are highly toxic to fish. P. parvum grows in many regions worldwide, and most recently caused 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. ToxANoWa-researchers are working on producing selected prymnesins to make them available for research and monitoring purposes. The team also currently works on the elucidation of the chemical structures of C-type prymnesins. This new variant of prymnesin was discovered by ToxANoWa-collaborators only recently. In addition, the ToxANoWa team are trying to produce a suitable antigen for raising prymnesin antibodies for the development of research and monitoring tools to simplify selective extraction and detection of these toxic chemicals. It is still unknown why this species is harmful to fish, but application of the modern technologies in ToxANoWa is expected to provide additional clues. This project is a collaboration between the Norwegian Veterinary Institute, the 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.

Publications from Cristin

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Funding scheme:

MARINFORSKHAV-Marine ressurser og miljø - havmiljø