Elin Dahlgren

Aquatic ecologist with a research focus on algal toxins, chemical ecology and fish health in the Baltic Sea. My work spans from small scale studies of naturally occurring toxins to large-scale environmental monitoring, ecosystem restoration and innovation for sustainable management of coastal ecosystems.

I am engaged in teaching activities within the courses:

• Ecology
• Assessment and Advice on the Principles of Fisheries Science 

My research focuses on how naturally occurring toxins and other bioactive compounds produced by algae influence aquatic ecosystems, food webs and fish health in the Baltic Sea. By combining field studies, environmental monitoring, laboratory experiments and analytical chemistry, I investigate how environmental change affects toxin production and how these compounds can be used to better understand ecosystem functioning and support restoration.

Toxic Tides – Algal toxins and fish health (FORMAS Explore 2026–2029)
Investigating whether naturally occurring algal toxins represent an overlooked mechanism behind recruitment failure in Baltic coastal fish populations. The project combines field surveys, laboratory experiments and ecological modelling to understand how toxin-producing algae influence fish health, predator–prey interactions and coastal ecosystem functioning.

Large-scale mapping of algal toxins in the Baltic Sea (Swedish Board of Agriculture / EU, 2024–2028)
Developing environmental monitoring of algal toxins through large-scale mapping of cyanotoxins and naturally occurring macroalgal toxins, with applications for mussel aquaculture, environmental assessment and climate adaptation.

Kingdom of Colors (Swedish Board of Agriculture/EU, 2024–2027)
Investigating whether pigments and biofluorescence can be used as indicators of toxin production in algae. The project combines aquatic chemical ecology with autonomous underwater robotics, multispectral imaging and AI-based data analysis through a collaboration with researchers at KTH to develop innovative tools for environmental monitoring and sustainable aquaculture.

Public engagement and innovation

Algverkstan – From Baltic Sea research to public engagement (Leader Stockholm Countryside, 2026–2028)

Project leader of Algverkstan, a Leader-funded initiative led by Nämdö Green Archipelago in partnership with SLU. The project explores new ways of engaging the public in Baltic Sea sustainability through hands-on activities, nature-based innovation and creative use of marine resources. By combining aquatic ecology, environmental monitoring, design and local entrepreneurship, Algverkstan aims to transform scientific knowledge into practical solutions and public engagement.

Thiamine deficiency in Baltic salmon

I coordinate and contribute to national environmental monitoring programmes focusing on the health of Baltic Sea fish populations and emerging environmental risks. I am also an active member of the ICES Working Group on Baltic Salmon and Trout (WGBAST), contributing to the development of monitoring methods and scientific advice for Baltic salmon.

A major part of my work concerns M74, the reproductive disorder affecting Baltic salmon caused by thiamine (vitamin B1) deficiency. I work with long-term monitoring, quality assurance and method development to improve the diagnosis and assessment of M74, including the development of standardized approaches for monitoring egg thiamine concentrations and evaluating population-level risks.

2022- Member of ICES assessment Working Group on Baltic Salmon and Trout 

2022- 2024 Coordinator for the Collaboration between SLU and the Baltic Sea Science Center at Skansen.

2021 - 2023 Member of the Baltic Sea Committee at The Royal Swedish Agricultural Academy 

2019- : Appointed as lay judge within The Land and Environment Court (Mark och Miljödomstolen).

• Swedish Environmental Protection Agency (SEPA). 2015- 2018.
• Guest researcher (50%), Stockholm University. 2015.
• Guest lecturer (50%), Södertörn University.  2015.
• Toxicologist, Swedish National Food Agency (NFA).  2014.
• Curator/researcher, Swedish museum of Natural history, Stockholm. 2012- 2013.
• Teaching assistant, Södertörn University. 2008.
• Field assistant, Norwegian Institute for Nature Research (NINA),  Uppsala University, University of Alberta, SLU. 1999-2002.

Main supervisor of PhD-student Manne Larsson "Large-scale mapping of
algal toxins and thiamine  in the Baltic Sea for climate adaptation of aquaculture" 2023- ongoing.

Co-supervisor of PhD-student Manuela Seehauser," The effects of climate change on cyanobacterial toxin production associated to mussel aquaculture" 2024-ongoing.

Co-supervisor of PhD-student Vittoria Todisco, “Quantifying the transfer of thiamin (vitamin B1) from producers to top predators”. Linnaeus University. 2020-2024.

Abdelgadir, M., Karlson, B., Dahlgren, E., & Olofsson, M. (2025). Prediction of present and future spatial occurrence of cyanobacteria and the toxin nodularin in the Baltic Sea. EGUsphere, 2025, 1-29.

Dahlgren, E., Persson, L., Lindqvist, D., & Näslund, J. (2025). Are there lingering effects of egg thiamine deficiency (M74) in thiamine-treated Baltic Sea salmon (Salmo salar) juveniles?. Aquaculture, 595, 741581.

Dahlgren, E., Lindqvist, D., Dahlgren, H. , Asplund, L , Lehtilä, K. 2016. Trophic transfer of naturally produced brominated aromatic compounds in a Baltic Sea food chain.  Chemosphere 144, 1597-1604.

Dahlgren, E., Enhus, C., Lindqvist, D., Eklund, B., Asplund, L. 2015. Induced production of brominated aromatic compounds in the algae Ceramium tenuicorne. Environ Sci. Pollut. res: 22, 18107 - 18114.

https://www.slu.se/centrumbildningar-och-projekt/algtox/

https://www.slu.se/centrumbildningar-och-projekt/slu-vattenforum/samverkan/bssc/

Nämdö Green Archipelago - Nämdö Green Archipelago