Associate Professor Linn Hoffmann, Our People, Department of Botany

Photo credit: Rebecca Parsons-King.

Marine botany

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Email: linn.hoffmann@otago.ac.nz

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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

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?

Image credit: G Faucher.

Potential MSc or PhD research projects

Effect of climate change on phytoplankton communities
Volcanic eruptions and their impact on phytoplankton communities
Assessing potential side effects of Ocean Alkalinity Enhancement for phytoplankton communities

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

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
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 (MSc): The effects of Ocean Acidification and increased irradiance on natural phytoplankton assemblages from water masses surrounding New Zealand
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 (PGDipSci): Grazing behaviour of coastal marine copepods
Madeleine Post (MSc): Sticky business – Adhesion of microplastics to common New Zealand macroalgae and implications for phenanthrene toxicity
Francie Rudminat (PhD): Dinitrogen fixation in the South Pacific – Effect of ocean acidification on marine diazotrophs
Jordan Sparrow (MSc): Phytoplankton variability in the Otago Harbour and adjacent shelf
Amirreza Zarekarizi (PhD): Effect of cultivation condition on the production of fucoxanthin by microalgae

Teaching

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

Publications

Hoffmann, L. (2024). Finding the sweet spot in the deep ocean [Research highlight]. Communications Biology, 7, 1544. doi: 10.1038/s42003-024-07220-3 Journal - Research Other

Olgun, N., Tari, U., Balci, N., Altunkaynak, S., Gürarslan, I., Yakan, S. D., … Hoffmann, L. (2024). Lithological controls on lake water biogeochemistry in maritime Antarctica. Science of the Total Environment, 912, 168562. doi: 10.1016/j.scitotenv.2023.168562 Journal - Research Article

Chan, J., Barnett, M., Bowie, D., Bradley, C., Bradley, T., Burritt, D., … Hoffmann, L., … Schweikert, K., … Samuelsson, L. (2023). Cooking and processing of seaweed to improve consumer acceptance, protein digestion and nutrient bioavailability. Proceedings of the 24th International Seaweed Symposium. (pp. 75). Retrieved from https://iss2023.net/ Conference Contribution - Published proceedings: Abstract

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 Journal - Research Article

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 Journal - Research Article

2024

Journal - Research Article

Journal - Research Other

Hoffmann, L. (2024). Finding the sweet spot in the deep ocean [Research highlight]. Communications Biology, 7, 1544. doi: 10.1038/s42003-024-07220-3

2023

Journal - Research Article

Zarekarizi, A., Hoffmann, L., & Burritt, D. J. (2023). The potential of manipulating light in the commercial production of carotenoids from algae. Algal Research, 71, 103047. doi: 10.1016/j.algal.2023.103047

Conference Contribution - Published proceedings: Abstract

Conference Contribution - Verbal presentation and other Conference outputs

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.

2022

Journal - Research Article

Meyers, M., Décima, M., Law, C. S., Gall, M., Barr, N., Miller, M. R., … Sabadel, A., Wing, S., & Hoffmann, L. (2022). No evidence of altered relationship between diet and consumer fatty acid composition in a natural plankton community under combined climate drivers. Journal of Experimental Marine Biology & Ecology, 551, 151734. doi: 10.1016/j.jembe.2022.151734

2021

Journal - Research Article

Zitoun, R., Achterberg, E. P., Browning, T. J., Hoffmann, L. J., Krisch, S., Sander, S. G., & Koschinsky, A. (2021). The complex provenance of Cu-binding ligands in the South-East Atlantic. Marine Chemistry, 237, 104047. doi: 10.1016/j.marchem.2021.104047

Allen, R. J., Summerfield, T. C., Harvey, B. P., Agostini, S., Rastrick, S. P. S., Hall-Spencer, J. M., & Hoffmann, L. J. (2021). Species turnover underpins the effect of elevated CO₂ on biofilm communities through early succession. Climate Change Ecology, 2, 100017. doi: 10.1016/j.ecochg.2021.100017

Espinel-Velasco, N., Tobias-Hünefeldt, S. P., Karelitz, S. E., Hoffmann, L. J., Morales, S. E., & Lamare, M. D. (2021). Reduced seawater pH alters marine biofilms with impacts for marine polychaete larval settlement. Marine Environmental Research, 167, 105291. doi: 10.1016/j.marenvres.2021.105291

Harvey, B. P., Allen, R., Agostini, S., Hoffmann, L. J., Kon, K., Summerfield, T. C., … Hall-Spencer, J. M. (2021). Feedback mechanisms stabilise degraded turf algal systems at a CO₂ seep site. Communications Biology, 4(1), 219. doi: 10.1038/s42003-021-01712-2

Conference Contribution - Published proceedings: Abstract

Cowley, G. T., McGraw, C. M., & Hoffmann, L. J. (2021). Environmental science in civic society and policy: Outreach for a better world today. Proceedings of the 14th Annual New Zealand Ocean Acidification Conference: Ocean Acidification in a Decade of Ocean Science. (pp. 25). Retrieved from http://nzoac.nz/conferences

Christensen, T. J. E., Zitoun, R., Hoffmann, L. J., Dillon, W. D. N., Dillingham, P. W., & McGraw, C. M. (2021). Redefining K_sp for calcite and aragonite with lower uncertainty in artificial seawater. Proceedings of the 14th Annual New Zealand Ocean Acidification Conference: Ocean Acidification in a Decade of Ocean Science. (pp. 24). Retrieved from http://nzoac.nz/conferences

2020

Journal - Research Article

Allen, R., Hoffmann, L. J., Larcombe, M. J., Louisson, Z., & Summerfield, T. C. (2020). Homogeneous environmental selection dominates microbial community assembly in the oligotrophic South Pacific Gyre. Molecular Ecology, 29, 4680-4691. doi: 10.1111/mec.15651

Allen, R., Summerfield, T. C., Currie, K., Dillingham, P. W., & Hoffmann, L. J. (2020). Distinct processes structure bacterioplankton and protist communities across an oceanic front. Aquatic Microbial Ecology, 85, 19-34. doi: 10.3354/ame01938

Hoffmann, L., Eggers, S. L., Allhusen, E., Katlein, C., & Peeken, I. (2020). Interactions between the ice algae Fragillariopsis cylindrus and microplastics in sea ice. Environment International, 139, 105697. doi: 10.1016/j.envint.2020.105697

Allen, R., Hoffmann, L. J., Law, C. S., & Summerfield, T. C. (2020). Subtle bacterioplankton community responses to elevated CO₂ and warming in the oligotrophic South Pacific Gyre. Environmental Microbiology Reports, 12(4), 377-386. doi: 10.1111/1758-2229.12844

Hopwood, M. J., Santana-González, C., Gallego-Urrea, J., Sanchez, N., Achterberg, E. P., Ardelan, M. V., … Hoffmann, L., … Turner, D. (2020). Fe(II) stability in coastal seawater during experiments in Patagonia, Svalbard, and Gran Canaria. Biogeosciences, 17(5), 1327-1342. doi: 10.5194/bg-17-1327-2020

Zitoun, R., Connell, S. D., Cornwall, C. E., Currie, K. I., Fabricius, K., Hoffmann, L. J., Lamare, M. D., Murdoch, J. H., … Sander, S. G., … Smith, A. M. (2020). A unique temperate rocky coastal hydrothermal vent system (Whakaari-White Island, Bay of Plenty, New Zealand): Constraints for ocean acidification studies. Marine & Freshwater Research, 71(3), 321-344. doi: 10.1071/mf19167

Gutiérrez-Rodriguez, A., Safi, K., Fernández, D., Forcén-Vázquez, A., Gourvil, P., Hoffmann, L., … Nodder, S. D. (2020). Decoupling between phytoplankton growth and microzooplankton grazing enhances productivity in Subantarctic waters on Campbell Plateau, southeast of New Zealand. Journal of Geophysical Research: Oceans, 125(2), e2019JC015550. doi: 10.1029/2019JC015550

Conference Contribution - Published proceedings: Abstract

Meyers, M., Décima, M., Currie, K. I., Hoffmann, L., & Wing, S. (2020). Salp distribution in coastal, subtropical, and subantarctic waters off the Southeast coast of New Zealand: Linking hydrology with ecosystem function. Proceedings of the Ocean Sciences Meeting (OSM). ME24E-0140. Retrieved from https://agu.confex.com/agu/osm20/meetingapp.cgi

Faucher, G., Wuttig, K., Bettoni, C., Erba, E., Koch, F., Trimborn, S., … Hoffmann, L. (2020). Influence of volcanic ash on growth and morphology of coccolithophore algae. Proceedings of the Ocean Sciences Meeting (OSM). CT41A-05. Retrieved from https://agu.confex.com/agu/osm20/meetingapp.cgi

2019

Journal - Research Article

Donahue, K., Klaas, C., Dillingham, P. W., & Hoffmann, L. J. (2019). Combined effects of ocean acidification and increased light intensity on natural phytoplankton communities from two Southern Ocean water masses. Journal of Plankton Research, 41(1), 30-45. doi: 10.1093/plankt/fby048

Zarekarizi, A., Hoffmann, L., & Burritt, D. (2019). Approaches for the sustainable production of fucoxanthin, a xanthophyll with potential health benefits. Journal of Applied Phycology, 31, 281-299. doi: 10.1007/s10811-018-1558-3

Conference Contribution - Published proceedings: Abstract

Meyers, M., McGraw, C., Décima, M., & Hoffmann, L. (2019). Design and employment of a new portable CO₂ system for ocean acidification experiments. Proceedings of the 12th New Zealand Ocean Acidification Workshop. (pp. 50). Retrieved from http://nzoac.nz

Meyers, M., Décima, M., Law, C., Deppeler, S., Saint-Macary, A., Gall, M., … Wing, S., & Hoffmann, L. (2019). Grazing of calanoid copepod Temora turbinata on natural prey communities during the CARIM Mesocosm 4 experiment. Proceedings of the 12th New Zealand Ocean Acidification Workshop. (pp. 39). Retrieved from http://nzoac.nz

Allen, R., Summerfield, T. C., Harvey, B., Agostini, S., & Hoffmann, L. J. (2019). Biofilm succession in an acidified ocean: Mechanistic insights from a volcanic CO₂ seep study. Proceedings of the 12th New Zealand Ocean Acidification Workshop. (pp. 12). Retrieved from http://nzoac.nz

Conference Contribution - Verbal presentation and other Conference outputs

Hoffmann, L. (2019, July). Phytoplankton community distribution along the Munida Transect. Verbal presentation at the NZ Marine Sciences Society (NZMSS) Joint Meeting with the Oceania Chondrichthyan Society, Dunedin, New Zealand.

2018

Journal - Research Article

Espinel-Velasco, N., Hoffmann, L., Agüera, A., Byrne, M., Dupont, S., Uthicke, S., … Lamare, M. (2018). Effects of ocean acidification on the settlement and metamorphosis of marine invertebrate and fish larvae: A review. Marine Ecology Progress Series, 606, 237-257. doi: 10.3354/meps12754

Conference Contribution - Published proceedings: Abstract

Meyers, M., Décima, M., Luan, Q., Hoffmann, L., & Wing, S. (2018). Copepod grazing and selectivity on natural prey communities during a high-temperature, low-pH mesocosm experiment. Proceedings of the 11th New Zealand Ocean Acidification Workshop. (pp. 19). Retrieved from http://nzoac.nz

Espinel, N., Dupont, S., Uthicke, S., Byrne, M., Agüera, A., Hoffmann, L., & Lamare, M. (2018). The potential effects of ocean acidification on the settlement and metamorphosis of marine larvae: A review and with reference to CARIM experiments. Proceedings of the 11th New Zealand Ocean Acidification Workshop. (pp. 15). Retrieved from http://nzoac.nz

Allen, R., Rudminat, F., Law, C., Hoffmann, L., & Summerfield, T. (2018). Bacterioplankton resistance to acidification and warming in the oligotrophic ocean. Proceedings of the 11th New Zealand Ocean Acidification Workshop. (pp. 7). Retrieved from http://nzoac.nz

2017

Journal - Research Article

Faucher, G., Hoffmann, L., Bach, L. T., Bottini, C., Erba, E., & Riebesell, U. (2017). Impact of trace metal concentrations on coccolithophore growth and morphology: Laboratory simulations of Cretaceous stress. Biogeosciences, 14(14), 3603-3613. doi: 10.5194/bg-14-3603-2017

Shatova, O. A., Wing, S. R., Hoffmann, L. J., Wing, L. C., & Gault-Ringold, M. (2017). Phytoplankton community structure is influenced by seabird guano enrichment in the Southern Ocean. Estuarine, Coastal & Shelf Science, 191, 125-135. doi: 10.1016/j.ecss.2017.04.021

Conference Contribution - Published proceedings: Abstract

Rudminat, F., Law, C., Hoffmann, L., & Summerfield, T. (2017). Bacterioplankton community response to elevated CO₂ and/or temperature in the South Pacific. Proceedings of the 10th New Zealand Ocean Acidification Workshop. (pp. 26). Retrieved from http://www.otago.ac.nz/oceanacidification/news/index.html

Law, C., Barr, N., Northcote, L., Gutierrez-Rodriguez, A., Decima, M., Marriner, A., … Fang, Z., Deans, F., Allen, R., Hoffmann, L., Baltar, F., & Gall, M. (2017). How will coastal plankton respond to increasing CO₂? Preliminary results from the first two CAIRM mesocosm experiments. Proceedings of the 10th New Zealand Ocean Acidification Workshop. (pp. 20). Retrieved from http://www.otago.ac.nz/oceanacidification/news/index.html

Hoffmann, L., & Donahue, K. (2017). Phytoplankton community composition response to ocean acidification and increased light intensities. Proceedings of the 10th New Zealand Ocean Acidification Workshop. (pp. 17). Retrieved from http://www.otago.ac.nz/oceanacidification/news/index.html

Allen, R., Hoffmann, L., & Summerfield, T. (2017). The ecological and evolutionary importance of genetic diversity in phytoplankton responses to ocean acidification. Proceedings of the 10th New Zealand Ocean Acidification Workshop. (pp. 11). Retrieved from http://www.otago.ac.nz/oceanacidification/news/index.html

2016

Journal - Research Article

Shatova, O., Wing, S. R., Gault-Ringold, M., Wing, L., & Hoffmann, L. J. (2016). Seabird guano enhances phytoplankton production in the Southern Ocean. Journal of Experimental Marine Biology & Ecology, 483, 74-87. doi: 10.1016/j.jembe.2016.07.004

Conway, T. M., Hoffmann, L. J., Breitbarth, E., Strzepek, R. F., & Wolff, E. W. (2016). The growth response of two diatom species to atmospheric dust from the Last Glacial Maximum. PLoS ONE, 11(7), e0158553. doi: 10.1371/journal.pone.0158553

Conference Contribution - Published proceedings: Abstract

Hoffmann, L. J., & Kearney, E. (2016). Effect of ocean acidification on diatom frustule stability. Proceedings of the 4th International Symposium on the Ocean in a High-CO₂ World. Retrieved from http://www.highco2-iv.org/

2015

Conference Contribution - Published proceedings: Abstract

Shatova, O., Wing, S., Hoffmann, L., Jack, L., & Gault-Ringold, M. (2015). Seabird guano enhances phytoplankton production in the Southern Ocean. Geophysical Research Abstracts, 17, EGU2015-166. [Abstract]

2013

Journal - Research Article

Olgun, N., Duggen, S., Langmann, B., Hort, M., Waythomas, C. F., Hoffmann, L., & Croot, P. (2013). Geochemical evidence of oceanic iron fertilization by the Kasatochi volcanic eruption in 2008 and the potential impacts on Pacific sockeye salmon. Marine Ecology Progress Series, 488, 81-88. doi: 10.3354/meps10403

Tatters, A. O., Roleda, M. Y., Schnetzer, A., Fu, F., Hurd, C. L., Boyd, P. W., … Hoffmann, L. J., & Hutchins, D. A. (2013). Short- and long-term conditioning of a temperate marine diatom community to acidification and warming. Philosophical Transactions of the Royal Society B, 368(1627), 20120437. doi: 10.1098/rstb.2012.0437

Hoffmann, L. J., Breitbarth, E., McGraw, C. M., Law, C. S., Currie, K. I., & Hunter, K. A. (2013). A trace-metal clean, pH-controlled incubator system for ocean acidification incubation studies. Limnology & Oceanography: Methods, 11, 53-61. doi: 10.4319/lom.2013.11.53

Conference Contribution - Published proceedings: Abstract

Law, C. S., Breitbarth, E., Hoffmann, L., McGraw, C., Langlois, R. R., LaRoche, J., … Safi, K. (2013). Are all nitrogen fixers ocean acidification "winners"? Proceedings of the 6th New Zealand Ocean Acidification Workshop. (pp. 33). Retrieved from http://www.otago.ac.nz/oceanacidification/news/

2012

Journal - Research Article

Smetacek, V., Klaas, C., Strass, V. H., Assmy, P., Montresor, M., Cisewski, B., … Hoffmann, L. J., … Wolf-Gladrow, D. (2012). Deep carbon export from a Southern Ocean iron-fertilized diatom bloom. Nature, 487, 313-319. doi: 10.1038/nature11229

Hoffmann, L. J., Breitbarth, E., Boyd, P. W., & Hunter, K. A. (2012). Influence of ocean warming and acidification on trace metal biogeochemistry. Marine Ecology Progress Series, 470, 191-205. doi: 10.3354/meps10082

Law, C. S., Breitbarth, E., Hoffmann, L. J., McGraw, C. M., Langlois, R. J., LaRoche, J., … Safi, K. A. (2012). No stimulation of nitrogen fixation by non-filamentous diazotrophs under elevated CO₂ in the South Pacific. Global Change Biology, 18(10), 3004-3014. doi: 10.1111/j.1365-2486.2012.02777.x

Hoffmann, L. J., Breitbarth, E., Ardelan, M. V., Duggen, S., Olgun, N., ..., & Wängberg, S.-Å. (2012). Influence of trace metal release from volcanic ash on growth of Thalassiosira pseudonana and Emiliania huxleyi. Marine Chemistry, 132–133, 28-33. doi: 10.1016/j.marchem.2012.02.003

Conference Contribution - Published proceedings: Abstract

McGraw, C. M., Breitbarth, E., Hoffmann, L., & Hunter, K. A. (2012). Trace-metal clean automated culture system for ocean acidification experiments. Proceedings of the Ocean Sciences Meeting. (pp. 307-308). Retrieved from http://www.sgmeet.com/osm2012/

2011

Journal - Research Article

Wilken, S., Hoffmann, B., Hersch, N., Kirchgessner, N., Dieluweit, S., Rubner, W., Hoffmann, L. J., … Peeken, I. (2011). Diatom frustules show increased mechanical strength and altered valve morphology under iron limitation. Limnology & Oceanography, 56(4), 1399-1410. doi: 10.4319/lo.2011.56.4.1399

2010

Journal - Research Article

Breitbarth, E., Achterberg, E. P., Ardelan, M. V., Baker, A. R., Bucciarelli, E., Chever, F., … Hoffmann, L., Hunter, K. A., … Ye, Y. (2010). Iron biogeochemistry across marine systems: Progress from the past decade. Biogeosciences, 7(3), 1075-1097.

Duggen, S., Olgun, N., Croot, P., Hoffmann, L., Dietzel, H., Delmelle, P., & Teschner, C. (2010). The role of airborne volcanic ash for the surface ocean biogeochemical iron-cycle: A review. Biogeosciences, 7(3), 827-844.

2009

Journal - Research Article

Breitbarth, E., Gelting, J., Walve, J., Hoffmann, L. J., Turner, D. R., Hassellöv, M., & Ingri, J. (2009). Dissolved iron (II) in the Baltic Sea surface water and implications for cyanobacterial bloom development. Biogeosciences, 6, 2397-2420.