Hannes Baumann

I am broadly interested in studying how fish populations are adapted to the natural variability in their environment and how they may therefore react to unfolding anthropogenic changes in our oceans and coastal waters. This includes changes in pH (ocean acidification) and temperature (global warming), but also ubiquitous man-made alterations to the marine food web and natural mortality patterns (fisheries exploitation and selection). I pursue these questions by employing a healthy mix of experimental, field, and modeling approaches with tools ranging widely from otolith microstructure and microchemistry, fish physiology, to population dynamics and evolutionary genetics. Specifically, our current two foci are: (i) understanding local and regional adaptation and vulnerability in coastal fish to co-occurring acidification and hypoxia, and (2) reconstructing a decade-scale historical growth distribution of commercial species (e.g. Georges Bank haddock) to investigate changes due to climate and fishing pressure.

Hannes Baumann: CV

Oceanography Students

Lucas Jones – M.Sc. Student

Callie Concannon – M.Sc. Student

Oceanography Alumni

Christopher Murray – Ph.D. 2018

Julie Pringle – M.Sc. 2018

Jacob Snyder – M.Sc. 2017

Courses Taught

BIOL 1108: Principles of Biology (FS 2015, FS2016, FS2017, FS2018)

“Principles of Biology” is a lecture and lab course and together with BIOL 1107 forms an integral component of undergraduate STEM education at UConn Avery Point. The course and lab will serve as an introduction to the chemical units of life, ecology, plant diversity, physiology, and anatomy.
Haeckel image

MARN 4018/5018: Ecology of Fishes (SS2015, SS2016, SS2017, SS2018)


“Ecology of Fishes” introduces and discusses classic topics of fish ecology such as distribution, feeding, bioenergetics, growth, larval fish ecology, biotic interactions or life history evolution, with the additional goal of providing a forum to discuss contemporary research of these topics. For each weeks topic, a lecture is followed by student-led discussions on topic-relevant publications of their choice. Instead of merely passing on what is already known, the main objective of each class is to identify issues that are still insufficiently understood and thus require further research. Particular emphasis is placed on issues that are somehow still debated, novel, or unresolved. Although we won’t be able to avoid touching on fish anatomy, physiology, or taxonomy, these have been covered elsewhere and are thus not the priority of this course. In addition, we will also have one special seminar covered by a guest speaker.


Therkildsen, N. and Baumann, H. 2018. Collaborative research: The genomic underpinnings of local adaptation despite gene flow along a coastal environmental cline. NSF-OCE #1756316 ($325,388 3 years)

Baumann, H., Wiley, D. Kaufman, L., Valentine, P., and Gallager, S. 2016. Sensitivity of larval and juvenile sand lance Ammodytes dubius on Stellwagen Bank to predicted ocean warming, acidification, and deoxygenation. Northeast Regional SeaGrant Consortium ($198,393 2 years)

Dam, H., Baumann, H., Finiguerra, M., and Pespeni, M. 2016. Collaborative Research: Transgenerational phenotypic and genomic responses of marine copepods to the interactive effects of temperature and CO2. NSF-OCE #1550180 ($609,684 3 years)

Dam, H. Baumann, H. and Finiguerra, M. 2016. Predicting the performance of the copepod Acartia tonsa under future conditions of temperature and CO2. Connecticut Sea Grant College Program ($149,969 2 years)

Baumann, H. and Nye, J. 2015. Collaborative research: Understanding the effects of acidification and hypoxia within and across generations in a coastal marine fish. NSF-OCE #1536336 ($829,035 3 years)

Baumann, H. and Rader, L. 2015. Lifting a treasure: Full digitization of Project Oceanology’s 40+ years of coastal research data in Long Island Sound Connecticut Sea Grant Project #PD-15-14 ($5,000 3 months)

Baumann, H. and McBride, R.S. 2012. Calibration of the scale and otolith size vs. fish size relationship for Georges Bank haddock. NOAA-NMFS. $14,800

Baumann, H. and Gobler, C.J. 2011. Will rising CO2 levels is the ocean affect growth and survival of marine fish early life stages? NSF-OCE #1097840 ($650,000 3 years)

Conover, D.O. (transferred to Baumann, H. in 2010). 2008. Local adaptation across latitudes: spatial scales, gene flow, and correlates of countergradient variation” NSF-OCE #0425830 ($860,684 3 years).


*denotes author/co-author is a student in the Baumann Lab


  1. Munday, P.L., Rummer, J.L. and Baumann, H.
    Chapter 10. Adaptation and evolutionary responses to high CO2
    In: Grosell, M. Munday, P.L., Brauner, C. and Farell, A.P. Farell (eds) Fish Physiology Volume 37: Carbon Dioxide Elsevier (in press)
  1. Pringle, J.W.* and Baumann, H.
    Sex-specific growth and survival in young-of-the-year Atlantic silversides inferred from otolith microstructure analysis
    Marine Ecology Progress Series (in revision)
  1. Therkildsen, N.O. and Baumann, H.
    A comprehensive non-redundant reference transcriptome for the Atlantic silverside Menidia menidia
    Marine Genomics (in review)
  1. Murray, C.S.*, Wiley, D., and Baumann, H.
    High sensitivity of a keystone forage fish to ocean acidification and warming
    Conservation Physiology (in review)
  1. Breitburg, D.L., Baumann, H., Sokolova, I.M., and Frieder, C.A.
    Multiple stressors – forces that combine to worsen deoxygenation and its effects. Chapter 6 In: Ocean deoxygenation: everyone’s problem. Causes, impacts, consequences and solutions.
    International Union for Conservation of Nature (IUCN). Report # (in press)
  1. Therkildsen, N.O., Wilder, A.P., Conover, D.O., Munch, S.B., Baumann, H., and Palumbi, S.R. (2019)
    Contrasting genomic shifts underlie parallel phenotypic evolution in response to fishing
    Science 365:487-490
    Related perspective: Fishing for answers Science 365: 443-444 | Cornell Press release | UConn Today
  1. Baumann, H. (2019)
    Experimental assessments of marine species sensitivities to ocean acidification and co-stressors: how far have we come?
    Canadian Journal of Zoology 97:399-408
  1. Snyder, J.T*, Whitney, M.M., Dam, H.G., Jacobs, M.W., and Baumann, H. (2019)
    Citizen science observations reveal rapid, multi-decadal ecosystem changes in eastern Long Island Sound
    Marine Environmental Research 146: 80-88


  1. Baumann, H., Cross, E.L., and Murray, C.S. (2018)
    Robust quantification of fish early life CO2 sensitivities via serial experimentation
    Biology Letters 14:20180408
  1. Murray, C.S. and Baumann, H. (2018)
    You better repeat it: complex temperature × CO2 effects in Atlantic silverside offspring revealed by serial experimentation
    Diversity 10:69
  1. Madigan, D.J., Li, M., Runsheng, Y., Baumann, H., Snodgrass, O.E., Dewar, H., Krabbenhoft, D.P., Baumann, Z., Fisher, N.S., Balcom, P., Sunderland, E.M. (2018)
    Mercury stable isotopes reveal influence of foraging depth on mercury concentrations and growth in Pacific bluefin tuna
    Environmental Science & Technology 52:6256-6264
  1. Baumann, H., Parks, E.M.*, and Murray, C.S.* (2018)
    Starvation rates in larval and juvenile Atlantic silversides (Menidia menidia) are unaffected by high CO2 conditions.
    Marine Biology 165:75-83
  1. Snyder, J.T.*, Murray, C.S.*, and Baumann, H. (2018)
    Potential for maternal effects on offspring CO2 sensitivities in the Atlantic silverside (Menidia menidia).
    Journal of Experimental Marine Biology and Ecology 499:1-8
  1. Baumann, H. and Smith, E. (2018)
    Quantifying metabolically-driven pH and oxygen fluctuations in US nearshore habitats at diel to interannual time-scales
    Estuaries & Coasts 41:1102-1117


  1. Dam, H.G. and Baumann, H.
    Climate change, zooplankton and fisheries.
    In: Phillips B, Perez-Ramirez M (eds) The impacts of climate change on fisheries and aquaculture. Wiley/Blackwell (November 2017)
  1. Baumann, Z., Mason, R.P., Conover, D.O., Balcom, P., Chen, C.Y., Buckman, K.L., Fisher, N.S., and Baumann, H. (2017)
    Mercury bioaccumulation increases with latitude in a coastal marine fish (Atlantic silverside Menidia menidia).
    Canadian Journal of Fisheries and Aquatic Sciences 74:1009-1015
  1. Murray, C.S.*, Fuiman, L., and Baumann, H. (2017)
    Consequences of elevated CO2 exposure across multiple life stages in a coastal forage fish.
    ICES Journal of Marine Science 74:1051-1061


  1. Gobler, C.J. and Baumann, H. (2016)
    Hypoxia and acidification in ocean ecosystems: Coupled dynamics and effects on marine life.
    Biology Letters 12:20150976
  1. Baumann, H. (2016)
    Combined effects of ocean acidification, warming, and hypoxia on marine organisms.
    Limnology and Oceanography e-Lectures 6:1-43
  1. O’Leary, S.J., Martinez, C.M., Baumann, H., Abercrombie, D.L., Conover, D.O., Poulakis, G.R., Murray, C.H., Feldheim, K.A., Chapman, D.D. (2016)
    Population genetics and geometric morphometrics of the Key silverside, Menidia conchorum, a marine fish in a highly fragmented inland habitat.
    Bulletin of Marine Science 92:33-50


  1. Baumann, H., Wells, R.J.D., Rooker, J.R., Baumann, Z.A., Madigan, D.J., Dewar, H., Snodgrass, O.E., and Fisher, N.S. (2015)
    Combining otolith microstructure and trace elemental analyses to infer the arrival of Pacific bluefin tuna juveniles in the California Current Ecosystem.
    ICES Journal of Marine Science 72: 2128-2138.
  1. Peck, M.A., Baumann, H., Clemmesen, C., Herrmann, J.-P., Moyano, M., and Temming A. (2015)
    Calibrating and comparing somatic-, nucleic acid-, and otolith-based indicators of growth and condition in young juvenile European sprat (Sprattus sprattus).
    Journal of Experimental Marine Biology and Ecology 147: 217-225.
  1. Malvezzi, A.J.*, Murray, C.M.*, Feldheim, K.A., Dibattista, J.D., Garant, D., Gobler, C.J., Chapman, D.D., and Baumann, H. (2015)
    A quantitative genetic approach to assess the evolutionary potential of a coastal marine fish to ocean acidification.
    Evolutionary Applications 8: 352-362.
  1. Yencho, M.A, Jordaan, A., Cerrato, R.M., Baumann, H. and Frisk, M.G. (2015)
    Growth and mortality in coastal populations of Winter Flounder: implications for recovery of a depleted population.
    Marine and Coastal Fisheries 7: 246-259.
  1. Depasquale, E.*, Baumann, H., and Gobler, C.J. (2015)
    Variation in early life stage vulnerability among Northwest Atlantic estuarine forage fish to ocean acidification and low oxygen.
    Marine Ecology Progress Series
    523: 145-156
  1. Baumann, H., Wallace, R.B., Tagliaferri, T., and Gobler, C.J. (2015)
    Large natural pH, CO2 and O2 fluctuations in a temperate tidal salt marsh on diel, seasonal, and interannual time scales.
    Estuaries & Coasts 38: 220-231.


  1. Murray, C.M.*, Malvezzi, A., Gobler, C.J., and Baumann, H. (2014)
    Offspring sensitivity to ocean acidification changes seasonally in a coastal marine fish.
    Marine Ecology Progress Series 504: 1-11 (Feature Article)
  1. Pfister, C., Esbaugh, A., Frieder, C., Baumann, H., Bockmon, E., White, M., Carter, B., Benway, H., Blanchette, C. Carrington, E., McClintock, J., McCorkle, D., McGillis, W., Mooney, T., Zivieri, P. (2014)
    Detecting the unexpected: A research framework for ocean acidification.
    Environmental Science & Technology 48: 9982-9994
  1. Wallace, R.B., Baumann, H., Grear, J., Aller, R.C., and Gobler, C.J. (2014)
    Coastal ocean acidification: The other eutrophication problem.
    Estuarine, Coastal, and Shelf Science 148: 1-13
  1. Gobler, C.J., Depasquale, E., Griffith, A., and Baumann, H. (2014)
    Hypoxia and acidification have additive and synergistic negative effects on the growth, survivial, and metamorphosis of early life stage bivalves.
    PLOS ONE 9(1):e83648 | Stony Brook Press Release
  1. Brown, E.E., Baumann, H., and Conover D.O. (2014)
    Evidence for temperature and photoperiod effects on sex determination in a fish.
    Journal of Experimental Marine Biology and Ecology 461: 39-43


  1. Baumann, H. and Doherty, O. (2013)
    Decadal changes in the world’s coastal latitudinal temperature gradients.
    PLoS ONE 8:e67596
  1. Baumann, Z., Casacuberta, N., Baumann, H., Masqué, P., and Fisher, N. S. (2013)
    Natural and Fukushima-derived radioactivity in macroalgae and mussels along the Japanese shoreline.
    Biogeosciences 10: 3809-3815
  1. Baumann, H., Sutherland, S.J., and McBride, R.S. (2013)
    Longitudinal length back-calculations from otoliths and scales differ systematically in haddock.
    Transactions of the American Fisheries Society 142: 184-192


  1. Buesseler, K.O., Jayne, S.R., Fisher, N.S., Rypina, I.I., Baumann, H., Baumann, Z., Breier, C.F., Douglass, E.M., George, J., Macdonald, A.M., Miyamoto, H., Nishikawa, J., Pike, S.M., Yoshida, S. (2012)
    Fukushima-derived radionuclides in the ocean and biota off Japan.
    Proceedings of the National Academy of Sciences 109: 5984-5988 | WHOI press release.
  1. Baumann, H., Talmage, S.C., and Gobler, C.J. (2012).
    Reduced early life growth and survival in a fish as a direct response to elevated CO2 levels.
    Nature Climate Change 2: 38-41 | SBU press release.
  1. Voss, R., Peck, M.A., Hinrichsen, H.-H., Clemmesen, C., Baumann, H., Stepputtis, D., Bernreuther, M., Schmidt, J.O., Temming, A., and Koester, F.W. (2012)
    Recruitment processes in Baltic sprat – a re-evaluation of GLOBEC-Germany hypotheses.
    Progress in Oceanography 107:61-79
  1. Peck, M.A., Baumann, H., Bernreuther, M., Clemmesen, C., Herrmann, J.-P., Haslob, H., Kanstinger, P., Koester, F., Petereit, C., Temming, A., and Voss, R. (2012)
    The ecophysiology of Sprattus sprattus in the Baltic and North Seas.
    Progress in Oceanography 103:42-57.
  1. Günther, C.C., Temming, A., Herrman, J.-P., Huwer B., Baumann H., Clemmesen-Bockelmann, C., Möllmann, C. (2012)
    A novel length back-calculation approach accounting for ontogenetic changes in the fish length – otolith size relationship during the early life of sprat (Sprattus sprattus L.).
    Canadian Journal of Fisheries and Aquatic Sciences 69:1-16



  1. Baumann, H., Rosales-Casián, J.A., and Conover, D.O. (2012)
    Contrasting latitudinal variations in vertebral number and sex determination in Pacific versus Atlantic silverside fishes.
    Copeia 2012: 342-351


  1. Baumann, H. and Gagliano, M. (2011)
    Changing otolith:fish size ratios during settlement in two tropical damselfishes.
    Helgoland Marine Research 65: 425-429
  1. Baumann, H. and Conover, D.O. (2011)
    Adaptation to climate change: contrasting patterns of thermal-reaction-norm evolution in Pacific vs. Atlantic silversides.
    Proceedings of the Royal Society:B 278: 2265-2273


  1. Conover, D. O. and Baumann, H. (2009).
    The role of experiments in understanding fishery-induced evolution.

    Evolutionary Applications 2: 276-290
  1. Baumann, H., Voss, R., and Malzahn, A., and Temming, A. (2009)
    The German Bight (North Sea) is a nursery area for both locally and externally produced sprat juveniles.
    Journal of Sea Research 61:234-243


  1. Baumann, H., Voss, R., Hinrichsen, H.-H., Mohrholz, V., Schmidt, J.O., and Temming, A. (2008)
    Investigating the selective survival of summer- over spring-born sprat, Sprattus sprattus, in the Baltic Sea.
    Fisheries Research 91: 1-14


  1. Stransky, C., Baumann, H., Fevolden, S.-E., Harbitz, A., Høie, H., Nedreass, K.H., Salberg, A.-B., Skarstein, T.H. (2007)
    Separation of Norwegian coastal cod and Northeast Arctic cod by outer otolith shape analysis.
    Fisheries Research 89: 159-166
  1. Baumann, H., Peck, M.A., Götze, E., and Temming, A. (2007)
    Starving early juvenile sprat, Sprattus sprattus L., in Western Baltic coastal waters: evidence from combined field and laboratory observations in August/September 2003.
    Journal of Fish Biology 70: 853-866


  1. Baumann, H., Hinrichsen, H.-H., Voss, R., Stepputtis, D., Grygiel, W., Clausen, L.W., and Temming, A. (2006)
    Linking growth- to environmental histories in central Baltic young-of-the-year sprat, Sprattus sprattus: an approach based on otolith microstructure analysis and hydrodynamic modeling.
    Fisheries Oceanography 15: 465-476
  1. Baumann, H., Gröhsler, T., Kornilovs, G., Makarchouk, A., Feldman, V., and Temming, A. (2006)
    Temperature-induced regional and temporal growth differences in Baltic young-of-the-year sprat, Sprattus sprattus.
    Marine Ecology Progress Series 317: 225-236
  1. Baumann, H., Hinrichsen, H.-H., Moellmann, C., Koester, F.W., Malzahn, A.M., and Temming, A. (2006)
    Recruitment variability in Baltic sprat, Sprattus sprattus, is tightly coupled to temperature and transport patterns affecting the larval and early juvenile stages.
    Canadian Journal of Fisheries and Aquatic Sciences 63: 2191-2201
  1. Voss, R., Clemmesen, C., Baumann, H., and Hinrichsen, H.-H. (2006)
    Baltic sprat larvae: Coupling food availability, larval condition and survival.
    Marine Ecology Progress Series 308: 243-254


  1. Hinrichsen, H.-H., Kraus, G., Voss, R., Stepputtis, D., and Baumann, H. (2005)
    The general distribution pattern and mixing probability of Baltic sprat juvenile populations.
    Journal of Marine Systems 58: 52-66
  1. Baumann, H., Peck, M.A., and Herrmann, J.-P. (2005)
    Short-term decoupling of otolith and somatic growth induced by food level changes in post-larval Baltic sprat, Sprattus sprattus.
    Journal of Marine and Freshwater Research 56: 539-547


  1. Baumann, H., Pepin, P., Davidson, F.J.M., Mowbray, F., Schnack, D., and Dower, J.F. (2003)
    Reconstruction of environmental histories to investigate patterns of larval radiated shanny (Ulvaria subbifurcata) growth and selective survival in a large bay of Newfoundland.
    ICES Journal of Marine Science 60: 243-258


Baumann, H. et al. (2018) CO2-specific early life survival and growth of M. menidia from 20 experiments 2012-2017 doi:10.5061/dryad.4573j74

Murray, C.S. et al. (2018) CO2 x temperature-specific early life survival and growth of M. menidia from 5 experiments bco-dmo.org/dataset/732818

Snyder et al. (2018) Fatty acid profiles of M. menidia females and their unfertilized eggs

Snyder et al. (2018) Survival, length, and growth responses of M. menidia offspring from different females exposed to contrasting CO2 environmentsdoi: 10.1575/1912/bco-dmo.719449

Murray, C.S. et al. (2017) Long-term growth data of juvenile Menidia menidia reared at contrasting CO2 levels doi:10.1575/1912/bco-dmo.652124

Baumann, H. et al. (2017) Temperature, pH, DO monitoring in Mumford Cove, CT, USA 2015-2016

Baumann, H. et al. (2015) Otolith microstructure and trace elemental concentrations in juvenile Pacific bluefin tuna (Thunnus orientalis) caught off of Southern California in 2012. doi: 10.1594/PANGAEA.844813

Malvezzi, A. et al. (2015): A quantitative genetic approach to assess the evolutionary potential of a coastal marine fish to ocean acidification. doi:10.5061/dryad.bd6vs

Depasquale, E. et al. (2015): Growth, survival, hatching success in embryos and larvae of three coastal marine forage fish in relative to CO2 x oxygen. bco-dmo/dataset/551151

Murray, C. et al. (2014): Offspring sensitivity to ocean acidification changes seasonally in a coastal marine fish. doi: 10.1594/PANGAEA.838990

Baumann, H. et al. (2012): Seawater carbonate chemistry, length and survival of Inland silverside, Menidia beryllina, during experiments, 2012. doi:10.1594/PANGAEA.773850

Baumann, H. et al. (2012): (Appendix) Vertebral number of topsmelt, Atherinops affinis, adults and offspring from different latitudes along the North-American Pacific coast. doi:10.1594/PANGAEA.787095

Baumann, H., and Conover, DO (2011): Thermal reaction norms of growth in Atlantic and Pacific silverside fishes. doi:10.1594/PANGAEA.773233

The complete, citable source data from Baumann’s PhD research on Baltic and North Sea sprat can be accessed through the PANGAEA Publishing Network for Geoscientific & Environmental Data Base

Selected Oral & Poster Presentations

  • Baumann H. 2016. “It’s a multistressor world: understanding the combined effects of ocean warming, acidification, and deoxygenation on marine organisms” University of Rhode Island Biological and Environmental Sciences Colloquium Series. Kingstown, RI, Invited seminar 26 Feb 2016.
  • Baumann H. 2015. “Plastic and evolutionary responses to ocean acidification”. Overview talk to the ocean acidification research community at the 3rd U.S. Ocean Acidification PI Meeting. Woods Hole Oceanographic Institution, Woods Hole, MA 5/11/15. Publicly available Prezi
  • Baumann H. 2015. Nets versus Nature: Have we indadvertedly made our fish smaller? Global Cafe seminar series. UConn Avery Point Campus 4/9/15
  • Baumann H., Smith E., and Gobler C.J. 2014. “Combined effects of low pH and low O2 on coastal organisms”. Invited speaker at the 7th National Summit on Coastal and Estuarine Restoration, 11/3/14, Washington D.C.
  • Baumann H., Wells D., Rooker J., Baumann Z., Madigan D., Dewar H., Snodgras O., and Fisher N. 2014. “Combining otolith microchemistry and microstructure analyses to infer transpacific migration patterns in juvenile Pacific bluefin tuna (Thunnus orientalis).” 5th International Otolith Symposium, 19-24 October 2014, Peguera/Mallorca (Spain)
  • Baumann H. 2014. “Ocean acidification research 2.0: Moving beyond the average open ocean” Seminar talk given in Storrs, CT (UConn, 4/15/14), Hamburg/Germany (IHF, 6/6/14), Kiel/Germany (Geomar, 6/12/14), Avery Point, CT (UConn MDS, 9/19/14), Edgewater, MD (SERC, 10/3/14), and Sandy Hook, NJ (NOAA, 10/9/14). Prezi accessible here
  • Baumann H. You break it, you own it – synchrony in nature, doomed by humans. TEDx talk at TEDx SBU, 10 October 2013 video
  • Baumann H.. Fish in a future acidified ocean – one less thing to worry about? Invited seminar presentation. (1) Northeast Fisheries Science Center, Woods Hole, MA (26 Oct 2011), (2) SoMAS, SBU, Stony Brook, NY. Friday Seminar (18 Nov 2011).
  • Baumann H., P. Pepin, F.Mowbray, and F. Davidson. 2002. Do growth patterns of larval radiated shanny, Ulvaria subbifurcata, reflect spatial and temporal differences in the environmental conditions? 2002. 26th Annual Larval Fish Conference, Bergen, Norway

For a complete list of oral and poster presentations, please refer to the CV on my lab website

Other literature

For a complete list of white papers, op-eds and other non peer-reviewed literature, please refer to the CV on my lab website