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Linn Hoffman 2023 image
Photo credit: Rebecca Parsons-King.

Marine botany
Phone: +64 3 479 7583

Research interests

I am a biological oceanographer with a focus on marine phytoplankton eco-physiology. My work mainly focusses on the response of phytoplankton communities to multiple environmental and climate change related stressors such as light, macronutrient concentration, temperature, ocean acidification, ocean warming, trace metal bioavailability, and microplastics and the implications for higher trophic levels of the food chain. In my research, I work collaboratively with scientists from multiple disciplines such as chemistry, palaeoceanography, geology, geochemistry, biochemistry, and ecology.

Associate Professor Hoffmann is director of the Future Ocean Research Theme.

Associate Professor Hoffmann is also a member of the Coastal People: Southern Skies collaboration that connects communities with world-leading, cross-discipline research to rebuild coastal ecosystems.
Coastal People: Southern Skies

Current research

Some of the research projects that I am currently involved in include:

Impacts of the Hunga Tonga - Hunga Ha'apai eruption on the marine ecosystem

HTHH eruption
Hunga Tonga - Hunga Ha'apai eruption, 15 January 2022. Image credit: NASA.

What is the impact of marine heatwaves on the abundance of the parasitic dinoflagellate Syndiniales?


How is phytoplankton species distribution in the Southern Ocean affected by climate change?

SEHACK-secchi plankton study.

How is coccolithophore morphology affected by trace metal availability?

Ehux image
Image credit: G Faucher.

Potential MSc or PhD research projects

  • Effect of climate change on energy transfer in the marine food chain
  • Effect of climate change on macroalgae reproduction
  • Effect of marine heatwaves on phytoplankton successional cycles
  • Effect of marine heatwaves on phytoplankton community structures
  • Volcanic eruptions and their impact on phytoplankton community structures

The University of Otago offers PhD scholarships to candidates with excellent academic records (irrespective of nationality). Please feel free to contact me if you are interested my research and would like to do your PhD in New Zealand. More information can be found on the Scholarships page.

Postgraduate students

  • Zoe Battershill (PhD): Seaweed as food for human consumption
  • Alex Charlton (PhD): Edible seaweed as future foods: the impact of season, environment and lifecycle on raw seaweeds
  • Sajini Dissanayake (PhD): The effect of ocean warming and ocean acidification on mixotrophic plankton and Syndiniales
  • Jordan Sparrow (MSc): Phytoplankton variability in the Otago Harbour and adjacent shelf
  • Yuhan Zhou (MSc): Marine viruses in New Zealand waters

Previous students

  • Ro Allen (PhD): Effect of ocean acidification and warming on natural Southern Ocean phytoplankton communities
  • Kelsey Donahue
  • Nadjejda Espinel (PhD): Changes in larval settlement and metamorphosis in marine invertebrates in response to reduced seawater pH
  • Hannah Heynderickx (PhD): The effects of ocean acidification on phytoplankton‐bacteria interactions in Southern Ocean waters
  • Morgan Meyers (PhD): How does ocean acidification affect copepod grazing in subAntarctic waters?
  • Chittipat Nitithamyong
  • Madeleine Post (MSc)
  • Francie Rudminat (PhD): Dinitrogen fixation in the South Pacific – Effect of ocean acidification on marine diazotrophs
  • Amirreza Zarekarizi (PhD): Effect of cultivation condition on the production of fucoxanthin by microalgae



  • BIOL 123 Plants: How They Shape the World
  • BTNY 203 Marine and Freshwater Botany (coordinator)
  • BTNY 301 Plant Ecology (co-coordinator)
  • BTNY 465 Plant and Environment
  • ECOL 111 Ecology and Conservation of Diversity
  • ECOL211 Ecology of Communities and Ecosystems
  • ECOL212 Ecological Applications
  • ECOL313 Ecology Field Course
  • MARI 322 Coastal and Shelf Seas Oceanography

Science Communication interview

Scott Bagley, one of Science Communication's students undertook an interview with Linn in 2015.
Science Communication student Scott Bagley interviews Dr Linn Hoffmann


Seabrook, S., Mackay, K., Watson, S. J., Clare, M. A., Hunt, J. E., Yeo, I. A., … Hoffmann, L. J., Armstrong, E. A., & Williams, M. J. M. (2023). Volcaniclastic density currents explain widespread and diverse seafloor impacts of the 2022 Hunga Volcano eruption. Nature Communications, 14, 7881. doi: 10.1038/s41467-023-43607-2

Olgun, N., Tari, U., Balci, N., Altunkaynak, S., Gürarslan, I., Yakan, S. D., … Hoffmann, L. (2023). Lithological controls on lake water biogeochemistry in maritime Antarctica. Science of the Total Environment. Advance online publication. doi: 10.1016/j.scitotenv.2023.168562

Aflenzer, H., Hoffmann, L., Holmes, T., Wuttig, K., Genovese, C., & Bowie, A. R. (2023). Effect of dissolved iron (II) and temperature on growth of the Southern Ocean phytoplankton species Fragilariopsis cylindrus and Phaeocystis antarctica. Polar Biology, 46, 1163-1173. doi: 10.1007/s00300-023-03191-z

Tulloch, D., Gehricke, S., Shaw, C., & Hoffmann, L. (2023, June). Mitigation. Panel discussion at the Science-based Policy School for Climate Change, [Hybrid].

Hoffmann, L. (2023, August). Potential side effects of trace metal release from ocean alkalinity enhancement. Verbal presentation at the New Zealand Ocean Acidification Conference & Climate Change Resilience in Aquaculture Symposium, Nelson, New Zealand.

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