Climate adaptation and mapping of algal toxins associated to mussel farms

Last changed: 03 June 2024
Messel attached to substrate. Photo.

With ongoing climate change and lingering effects from eutrophication, an increase in cyanobacterial blooms and growth of filamentous algae is now observed in several places. Our project aims to understand the toxin production processes and how they relate to seasonal changes and environmental parameters. We strive to identify means of monitoring as well as safe periods for harvest of mussels farmed on the southeast coast of Sweden.

Monitoring of algae and/or toxin concentrations, and use of safe periods for harvest of aquaculture together with early warning systems via satellite data would make it possible to anticipate toxin surges and reduce their effects on the aquaculture industry. A deeper understanding of the ecology behind algal toxin production will also lead to opportunities to prevent high levels through adaptations in the design of operations.


We aim to develop tools and systems to enable adaptations in aquaculture to the exposure to algal toxins. This entails building knowledge about what affects the production and spread of these toxins and translating this into practical and applicable tools. This knowledge can also be used directly for planning regarding the design and function of operations.

Progression of the project

The elements included in the project involve knowledge acquisition through several studies both in the field and in the lab as well as developing, testing, and evaluating methods to monitor and predict levels of algal toxins now and in the future. The steps that the project will carry out are to develop:

  • System for early warning regarding the application of algal toxin through the use of SMHI's satellite data combined with local measurement data.
  • Measurement series regarding the seasonal variation of algal toxins and vitamins to validate the possibility of using the safe season for cultivation and production.
  • Species distribution models, which contribute with knowledge of where and when a high risk of toxins exists and risks occurring, now and in future climate scenarios.
  • Basis for how algal toxin levels are affected by different parts of the processing process of raw materials in aquaculture (with a focus on mussels).
  • Knowledge regarding transport and exposure routes for algal toxins and vitamins based on the production of filamentous algae and cyanobacteria and their occurrence in different habitats (with a focus on coastal and pelagic areas).
  • Quantifiable variables that can be entered into biogeochemical models of the presence/absence of algal toxin in accumulations of algae/bacteria under varying environmental conditions.
  • Suitable proxies to indicate the presence of algal toxins, such as gene expression combined with chlorophyll content in algae and the water mass.
  • A library of gene occurrence and gene expression linked to algal toxin production and exposure in aquaculture.

The work is primarily carried out as part of two doctoral projects, one focusing on cyanobacterial toxins and one on bromated halogenated compounds.

Spike covered in algal bloom. Photo.

Spike in algal bloom. Photo by: Elin Dahlgren, SLU.


The official name of the project: Large-scale mapping of algal toxins in the Baltic Sea for climate adaptation of aquaculture

Budget: 10 MSEK

Funder: Board of Agriculture

Planned project period: August 2023-August 2026