[Lab news] Callie attends UConn climate change symposium

UConn DMS students present their research (u.l. Kelly McGarry, u.r. Halle Berger, l.l. Sarah McCart, l.r. Alec Shub
By Callie Concannon. On April 30th, four graduate students from the Marine Science Department traveled to UConn, Storrs to present their research at UConn’s 2nd Climate Research Symposium cohosted by the Geology and Marine Science departments. The students were Kelly McGarry (Ph.D student; top left), Halle Berger (Master’s student; top right), Sarah McCart (Master’s student; bottom left) and Alec Shub (Master’s student; bottom right). Everyone’s presentations were well received, and Sarah McCart even won the graduate student poster competition!

The event featured two keynote speakers; Professor Margaret Rubega of UConn, and Professor Tim Cronin of MIT. Professor Rubega talked about science communication and how the scientific community could better communicate their climate change research to non-scientists without using overbearing jargon and too many words. Professor Cronin gave a speech on his past research on the suppression of Arctic air formation with climate warming.

  • McCart, S., Lund, D., Seeley, E., Asimov, P., Lewis, M., and Mudahy, A.L. Testing the sea level hypothesis with new results from the Pacific.
  • McGarry, K., Siedlecki, S., Alin, S., and Salisbury, J. Empirical models for estimating the carbonate system along the northeastern coast of the U.S.
  • Berger, H., Siedlecki, S., Matassa, C., Alin, S., Kaplan, I., Pilcher, D., and Newton, J. Using projections from regional oceanographic forecasts to assess the vulnerability of the Dungeness crab to climate change stressors.
  • Shub, A., Lund, D., and Mudahy, A.L., Does expansion of Antarctic bottom water result in storage of CO2 in the abyssal Atlantic?

[Lab news] Emma turns 30 and starts a new silverside experiment!

3 May 2019. It is Emma’s 30th birthday today, so naturally she celebrates it by starting a new, large experiment with Atlantic silversides, thus sharing her special day with more than 5,000 little embryos that are now developing in our system.

Like in our previous experiments, we are mimicking current and future coastal environments that fluctuate daily in CO2 and oxygen levels – thanks to our computer-controlled system that manipulates these levels in up to nine tanks simultaneously.

But this time, our additional goal is to keep track of sib-ship. We produced full sibs (same mother, same father), half-sibs (same mother or father, different father or mother) and unrelated individuals, and by keeping them separate we will later be able to calculate additive genetic variances in the various traits under different conditions (i.e., heritability) and examine trait correlations.

Breeding design

As usual, this could not be done by one person, so the entire lab helped preparing, seining, and fertilizing embryos on this frantic day. Great job all!


[Lab news] Whole life cycle CO2 fish are getting sampled

18 April 2019. This Thursday was a long day in the Baumann lab, because we sampled and processed over 200 adult silversides from a unique experiment. These fish were fertilized in the lab and reared from eggs to adulthood under different temperatures and contrasting CO2 conditions. We are interested to see, if future ocean conditions have measurable effects on this species fecundity, growth, and oocyte characteristics. We also took tissue and genetic samples, with an effective line-up of hands, i.e., Hannes, Emma, Chris, Callie and Lucas.
Good teamwork all!


[Publication] Brachiopods thicken shells to compensate for shell dissolution under future OA conditions

15 April 2019. Today, Emma is happy to report that Environmental Science & Technology have just published the latest paper from her PhD about brachiopod resilience to future ocean acidification. This project involved long-term culturing of a polar and a temperate brachiopod under future ocean acidification and warming conditions. Substantial shell dissolution posed a threat to both species under ocean acidification, with more extensive dissolution occurring in the polar species.

Unexpectedly, we discovered that brachiopods thicken their shell from the inner shell surface when extensive dissolution occurs at the outer shell surface under ocean acidification. This is an important finding to further our understanding of how predicted vulnerable marine calcifiers might cope under future environmental change.


Cross, E. L., Harper, E. M. and Peck, L. S. 2019. Thicker shells compensate extensive dissolution in brachiopods under future ocean acidification. Environmental Science & Technology (published online March 29, 2019).

[Publication] Perspective on experimental OA research published!

15 April 2019. Today, the Canadian Journal of Zoology published a perspective on the progress and challenges of experimental ocean acidification research, written by Hannes last year as an extension of keynote lectures on this topic given at the Annual meeting of the Canadian Zoological Society (St. John’s, NL, Canada) and the Gordon Research Symposium (Waterville Valley, NH). The perspective takes stock of the progress achieved in the field over past two decades in four key areas, hoping to inspire particularly new researchers to the field to build on this foundation.

Abstract: Experimental studies assessing the potential impacts of ocean acidification on marine organisms have rapidly expanded and produced a wealth of empirical data over the past decade. This perspective examines four key areas of transfor- mative developments in experimental approaches: (1) methodological advances; (2) advances in elucidating physiological and molecular mechanisms behind observed CO2 effects; (3) recognition of short-term CO2 variability as a likely modifier of species sensitivities (Ocean Variability Hypothesis); and (4) consensus on the multistressor nature of marine climate change where effect interactions are still challenging to anticipate. No single experiment allows predicting the fate of future populations. But sustaining the accumulation of empirical evidence is critical for more robust estimates of species reaction norms and thus for enabling better modeling approaches. Moreover, advanced experimental approaches are needed to address knowledge gaps including changes in species interactions and intraspecific variability in sensitivity and its importance for the adaptation potential of marine organisms to a high CO2 world.
Illustration of the Ocean Variability Hypothesis positing that the CO2 sensitivity of marine organisms is related to the magnitude of short-term CO2 fluctuations in their habitat (e.g., from nearshore to open ocean) and length of their early life stage durations. It suggests that the most CO2 tolerant marine organisms are those that develop fast and (or) in habitats with large contemporary CO2 fluctuations, whereas the potentially most vulnerable species are those that develop slowly in relatively stable open-ocean habitats.

[Media] WSHU public radio covers Project Oceanology story

4 April 2019. Following the publication of our study on the Project Oceanology time-series in Marine Environmental Research and the subsequent article about it in TheConversation, today the story was featured by WSHU public radio, in Ron Ropiak’s show “The Full Story“.

Have a listen, how Hannes describes both the findings and the significance of the Project Oceanology time series.


[Publication] The Project Oceanology time-series has been published!

Project Oceanology
Project Oceanology students onboard the “Enviro-Lab II” retrieve a trawl in the Thames River Mouth (Photo: Anna Sawin)

21 March 2019. We are happy to announce that Marine Environmental Research just published our most recent paper about long-term ecological change in eastern Long Island Sound based on data collected by Project Oceanology!For his Master’s thesis, Jacob Snyder painstakingly retrieved and digitized more than 40 years of environmental observations from Project Oceanology. This non-profit ocean literacy organization has educated middle and high school students on boat trips to nearby estuarine sites for decades. For the first time, his work allowed a quantitative evaluation of these data and glimpses into the abiotic and biotic changes in nearshore waters of Eastern Long Island Sound.


  • Citizen-science observations revealed rapid warming, acidification, and dissolved oxygen loss over the past 40 years in eastern Long Island Sound
  • Otter trawl catches showed significant decreases in overall species diversity and richness
  • Cold-water adapted species (American lobster, winter flounder) decreased, but warm-water adapted species (spider crabs) increased since 1997


Public outreach

News coverage: UConn Today | New Haven Register | The Hour | NonProfit Quarterly | WSHU Public Radio

Long-term changes in temperature, pH, and oxygen in the Thames River Mouth (eastern Long Island Sound)
Catch indices of four major species in Project Oceanology trawls over the past two decades

[Research News] F1000 Prime recommends Biology Letters article

Dear Dr Baumann,


Your article: Robust quantification of fish early life CO2 sensitivities via serial experimentation, Biology Letters, 2018 (DOI: 10.3410/f.734523360.793553721), has been recommended in F1000Prime as being of special significance in its field by F1000 Faculty Member Philip Munday.

You can read Dr Munday’s recommendation here

Munday P: F1000Prime Recommendation of [Baumann H et al., Biol Lett 2018 14(11)]. In F1000Prime, 11 Dec 2018; 10.3410/f.734523360.793553721

Thank you, Phil!

[Lab news] Chris defends his dissertation!

Chris smiling after his committee congratulated him on his dissertation defense (f.l.t.r: Chris Chamber, Chris Gobler (via Skype), Eric Schultz, Hans Dam, Chris Murray)
6 December 2018. Today, the whole Baumann lab is congratulating Chris Murray today on his great day of defending his PhD. Chris presented the essence of his research on climate change effects on coastal marine fish to a packed audience in the seminar room, fielded an array of questions, and showed his deep knowledge of the subject during the subsequent discussion with his committee.
Well done, Dr. Murray! We are all so very proud of you!

The bubbly is opened in the Rankin Lab in true experimenter fashion!
Chris Murray and Chris Chambers in front of the sand lance tank in the Rankin Lab

[Publication] Meta-analysis of silverside CO2 experiments published!

28 November 2018. Hannes, Emma, and Chris are happy to announce that Biology Letters just published our latest study, a meta-analysis of 20 standard CO2 exposure experiments conducted on Atlantic silverside offspring between 2012-2017. All these years of sustained experimental work resulted in the most robustly constrained estimates of overall CO2 effect sizes for a marine organism to date.
The study demonstrated:

  • A general tolerance of Atlantic silverside early life stages to pCO2 levels of ~2,000 µatm
  • A significant overall CO2 induced reduction of embryo and overall survival by -9% and -13%, respectively
  • The seasonal change in early life CO2 sensitivity in this species
  • The value of serial experimentation to detect and robustly estimate CO2 effects in marine organisms

Baumann, H., Cross, E.L., and Murray, C.S. Robust quantification of fish early life CO2 sensitivities via serial experimentation. Biology Letters 14:20180408

This figure shows the summary of early life responses to high CO2 conditions in Atlantic silversides across all experiments conducted between 2012-2017. Effect size was estimated using the log-transformed response ratio (A-D). Error bars are 95% confidence intervals. The responses are considered significant if the confidence interval does not include zero. Panels E-F: seasonal decomposition of response ratios, showing that silverside early life stages are most sensitive to high CO2 at the beginning and end of their spawning season.