Anna Gårdmark

I study the mechanisms of ecological and evolutionary dynamics of aquatic food webs. Fish communities and food webs respond to changing environments depending on their species interactions. These interactions are not static or uniform! Individuals engage in different interactions during their life, often depending on their body size. Their feeding interactions, in turn, determine individual development. This leads to interesting feedbacks between variation among individuals within populations, how individuals interact with their environment, and how they perform. My focus is to resolve how these feedbacks shape dynamics of fish populations, communities and food webs and their responses to global warming.

To study this, I lead the FishinFoodwebs research group where we combine dynamic modelling with laboratory and field mesocosm experiments. We also develop novel time series methods and apply these to long-term fish community data, often in the Baltic Sea but also in lake systems and elsewhere. Read more about our research and us here! 

Some ongoing projects on effects of global warming on fish & food webs are

• Fish community responses to rising temperatures and darker waters
• Marine extreme weather - ecological effects and risks to fisheries
• Warming-induced evolution in fish
• Bioaccumulation in food webs under global warming
• ClimePlan - ecological risk analyses climate-proofing impact assessments for ecosystem-based marine spatial planning
• VitaminSea - how does climate change affect access to nutritious aquatic foods in vulnerable regions?

Find out more about our research on climate change effects on fish communities and food webs here!

NEWS: Warming speeds up growth in females but reduces growth in large males - new paper. See publications.

PhD-students

• Olivia Bell 2022- Bioaccumulation of radionuclides in food webs under climate warming
• Benjamin Mooney 2022- Climate change and biomass distributions in aquatic food webs (co-supervisor)
• Jingyao Niu 2020- Ecological and evolutionary consequences of ecosystem warming in fish
• Foteini Elefteria Kappa (Gothenburg Univ.) 2024- Investigation of the feeding behavior and the role of harbour seals in the marine food web (co-supervisor)

Previous PhD-students

• Tharindu Bandara Herath (Umeå Univ.) 2020-2024 Marine food webs under changing climate. Impacts on food web efficiency and quality (co-supervisor)
• Viktor Thunell 2017-2023  Climate change impacts on dynamics of exploited
  fish communities
• Max Lindmark 2016-2020  How trophic interactions mediate physiological responses to climate change in food-webs
• Renee Van Dorst 2016-2020  Fish community responses to darker and warmer waters (co-supervisor)
• Philip Jacobson 2015-2020  Role of size-dependent resource- and habitat use for bioaccumulation (co-supervisor)
• Muriel-Marie MacPherson (Univ. Hamburg) 2013-2020 Ecosystem Assessment: Developing Environmental and Intrinsic Recruitment Indicators for Cod (Gadus morhua L.), Herring (Clupea harengus L.) and Sprat (Sprattus sprattus L.) in the Baltic and beyond (co-supervisor)
• Ulrika Beier 2013-2016  Habitat selection and indirect interactions in fish communities

Post-doc mentoring

• Jasper Croll 2024- Heatwave effects on herring dynamics and population structure

Previous post-doctoral fellows

• Elizabeth Duskey 2020-2023 How hypoxia and warming alters Baltic Sea food webs
• Wojciech Uszko 2019, 2021-2022 Intra- & interspecific size responses to warming in zooplankton
• David Gilljam 2019-2020 Evolutionary adaptations to warming in fish and eco-evolutionary dynamics
• Torbjörn Säterberg 2017, 2019-2020 Approximating food-web filtering of climate change responses in data poor systems
• Marian Torres 2014-2016  Developing pelagic food web indicators accounting for species interactions
• Grégoire Certain 2014-2016  Resolving climate change impacts on natural food-webs using multivariate time series approaches
• Magnus Huss 2009-2011  Effects of fishing on marine food-webs with size-dependent interactions
• Jens Olsson 2009-2010  Integrated Ecosystem Analyses of the Baltic Sea
• Anssi Vainikka 2006-2009  Fisheries-induced evolution of maturation in Baltic Sea fish

Looking for a MSc thesis project in community dynamics theory or aquatic food-web dynamics? Get in touch!

I publish with > 80 collaborators, so far in > 70 scientific articles, about 10 popular science articles and numerous export reports. Check Researchgate & Google Scholar for full list of publications and for citations.

Curious? Have a look at, for example:

• Van Dorst, R.M., Gårdmark, A., Kahilainen, K., Nurminen, L., Estlander, S., Huuskonen, H., Olin, M., Rask, M. & M. Huss. 2024. Ecosystem heating experiment reveals sex-specific growth responses in fish. Canadian Journal of Fisheries and Aquatic Sciences, 81: 90–96. doi: 10.1139/cjfas-2023-0034. open access here
• Lindmark, M., Karlsson, M. & A. Gårdmark. 2023. Larger but younger fish when growth outpaces higher mortality in heated ecosystem. eLife, 12:e82996. doi: 10.7554/eLife.82996. open access here
• Niu, J., Huss, M., Vasemägi, A. & A. Gårdmark. 2023. Decades of warming alters maturation and reproductive investment in fish. Ecosphere, 14:e4381. doi: 10.1002/ecs2.4381. open access here
• Lindmark, M., Ohlberger, J. & A. Gårdmark. 2022. Optimum growth temperature declines with body size within fish species. Global Change Biology, 28:2259–2271. doi: 10.1111/gcb.16067. open access here
• Jacobson, P., Whitlock, R., Huss, M., Leonardsson, K., Östergren, J. & A. Gårdmark. 2021. Growth variation of Atlantic salmon Salmo salar at sea affects their population-specific reproductive potential. Marine Ecology Progress Series, 671: 165-174. doi:10.3354/meps13734 open access here
• Gårdmark, A. & M. Huss. 2020. Individual variation and interactions explain food web responses to global warming. Philosophical Transactions of the Royal Society London Series B, 375: 20190449. doi: 10.1098/rstb.2019.0449. open access here
• Huss, M,. Lindmark, M., van Dorst, R.M., Jacobson, P. & A. Gårdmark. 2019. Large-scale experimental evidence of gradual size-dependent shifts in body size and growth of fish in response to warming. Global Change Biology, 5: 2285–2295. doi: 10.1111/gcb.14637. open access here
• Lindmark, M., Ohlberger, J., Huss, M. & A. Gårdmark. 2019. Size-based ecological interactions drive food web responses to climate warming. Ecology Letters, 22: 778–786. doi: 10.1111/ ele.13235. open access here
• Van Dorst, R.M., Gårdmark, A., Svanbäck, R., Beier, U., Weyhenmeyer, G.A. & M. Huss. 2019. Warmer and browner waters decrease fish biomass production. Global Change Biology, 25(4), 1395-1408. doi: 10.1111/gcb.14551. open access here
• Lindmark, M., Huss, M., Ohlberger, J. & A. Gårdmark. 2018. Temperature-dependent body size effects on population responses to climate warming. Ecology Letters, 21, 181–189. doi: 10.1111/ele.12880 open access here
• Certain, G., Barraquand, F. & A. Gårdmark. 2018. How do MAR(1) models cope with hidden nonlinearities in ecological dynamics? Methods in Ecology and Evolution, 1-21. doi: 10.1111/2041-210X.13021 open access here
• Gårdmark, A., Casini, M., Huss, M., Van Leeuwen, A., Hjelm, J., Persson, L. & de Roos, A. M. 2015. Regime shifts in exploited marine food-webs: detecting mechanisms underlying alternative stable states using size-structured community dynamics theory. Philosophical Transactions Royal Society, Series B, 370 (5), 20130262. open access here
• Bernes, C., Carpenter, S.R., Gårdmark, A., Larsson, P., Persson, L., Skov, C., Speed, J.D.M. & Van Donk, E. 2015. What is the influence of a reduction of planktivorous and benthivorous fish on water quality in temperate eutrophic lakes? A systematic review. Environmental Evidence, 4 (7).
• Östman, Ö., Karlsson, O., Pönni, J., Kaljuste, O., Aho, T & Gårdmark, A. 2014. Ecosystem changes and eco-evolutionary dynamics in body size of herring (Clupea harengus) in the Bothnian Sea. Evolutionary Ecology Research, 16: 417-433.
• Van Leeuwen, A., Gårdmark, A., Huss, M. & de Roos, A. M. 2014. Ontogenetic specialism in predators with multiple niche shifts prevents predator population recovery and establishment. Ecology, 95 (9), 2409-2422.
• Möllmann, C., Lindegren, M., Blenckner, T., Bergström, L., Casini, M., Diekmann, R., Flinkman, J., Müller-Karulis, B., Neuenfeldt, S., Schmidt, J. O., Tomczak, M. T., Voss, R. & Gårdmark, A. 2014. Implementing ecosystem-based fisheries management – from single-species to integrated ecosystem assessment and advice for Baltic Sea fish stocks. ICES Journal of Marine Sciences, 71 (5): 1187-1197.
• Gårdmark, A., Lindegren, M., Neuenfeldt, S., Blenckner, T., Heikinheimo, O., Müller-Karulis, B., Niiranen, S., Tomczak, M., Aro, E., Wikström, A. & Möllmann, C. 2013. Biological Ensemble Modelling to evaluate potential futures of living marine resources. Ecological Applications, 23(4), 742–754.
• Huss, M., de Roos, A.M., van Leeuwen, A., Casini, M. & Gårdmark, A. 2013. Cohort dynamics give rise to alternative stable community states. American Naturalist, 182(3), 374-392.

Curious of what’s up in the Baltic Sea food-webs or what happens in ecosystems when we fish? I happily give popular science talks, contribute to news articles popularing science or write popular science articles. Watch the SLU news site or get in touch.

Visit us on @FishinFoodwebs, Instagram, for news and fun research in our research group!

More on our research in FishinFoodwebs

You'll find me on ResearchGate and Google Scholar.