October, 2nd, 2017: Happy to announce that Estuaries and Coasts just published (online) our article that looked unifying principles of pH and DO fluctuations across many US nearshore habitats. The datasets belongs to the US Nearshore Estuaries Research Reserves System (NERRS) and is one of the most extensive monitoring datasets in coastal aquatic habitats. In this case, we used 15 years of continuous monitoring data (> 5 million data points) from 16 different reserves across the US Atlantic, Caribbean, Gulf of Mexico, and Pacific coasts and analyses short- to long-term variability in pH and DO fluctuations. Among the highlights:
Our analyses confirmed that large, metabolically driven fluctuations of pH and DO are a unifying feature of nearshore habitats. Even more so, we were able to show that across habitats, one can predict mean pH or mean diel pH fluctuations simply based on salinity and oxygen levels/fluctuations. This provides strong empirical evidence that common metabolic principles drive diel to seasonal pH/DO variations within as well as across a diversity of estuarine environments.
As expected, there are no monotonic trends in nearshore pH conditions, but interannual fluctuations that are of similar magnitude than the pH decrease predicted for the average surface ocean over the next three centuries.
By correlating weekly anomalies of pH, oxygen, and temperature, we found strong empirical support to the notion that coastal acidification — in addition to being driven by eutrophication and atmospheric CO2 increases — is exacerbated simply by warming, likely via increasing community respiration.
On 19-21 September 2017, Chris Murray and Hannes Baumann traveled to Fort Lauderdale, Florida, to attend the ICES (International Council for the Exploration of the Sea) Annual Science Conference in order to present our ongoing NSF and NOAA funded research on potential ocean acidification effects in Atlantic Silversides and Norther Sand lance. Due to Hurricane Irma, which had impacted all of Florida just a week earlier, it was a great relief that the conference could actually be successfully held.
From 11-16 July, Hannes, Chris, Jake (Baumann lab, UConn) and Teresa (Nye lab, Stony Brook) were presenting research from our common NSF project at the 41st Larval Fish Conference, organized by the Early Life History Section of the American Fisheries Society in Austin, TX.
Holding the fort and maintaining experiments at Avery Point were James, Julie, and Elle. Thank you for helping out.
We gave four talks in two sessions:
Baumann H., Snyder, J.T., and Murray, C.S. 2017. Quantifying offspring CO2-sensitivity in a fish: a meta-analysis.
Snyder, J.T., Murray, C.S., and Baumann H. 2017.
Potential for maternal effects on offspring CO2 sensitivity in a coastal marine fish
Murray, C.S., Snyder, J.T., and Baumann H. 2017. A multi-factorial evaluation of temperature-dependent CO2-effects in a coastal forage fish.
Schwemmer, T., Baumann H., and Nye, J. 2017.
Physiological effects of increased temperature and carbon dioxide on Atlantic silverside early life stages <
Here is how Jake rates his first international conference experience:
Austin Texas, July 2017. “Attending the Joint Meeting of Ichthyologists and Herpetologists was my first visit to Austin Texas and my first large-conference presentation. My presentation was part of the Larval Fish Conference, a sub-section of the larger meeting, and I quickly learned how welcoming the larval fish group of researchers, scientists, professionals, and students were. Having not been to a “destination” conference like this before, I had little expectations, but I had a lot of fun networking, discussing research, and socializing. I think the coolest non-conference related event was seeing the Mexican Free-Tailed bats that live in the Congress Street Bridge, as every night around sunset they leave to go feed. Seeing hundreds of thousands of bats stream out of the bridge was incredible, and something I’d highly recommend. The city of Austin was great, and I spent much of the first day (pre-conference) exploring the city in the scorching heat. Overall the Baumann Lab had an excellent time at the conference, and can’t wait for the next one!”
October 10th 2016 was a special day for our still young lab here at the University of Connecticut, Today, the ICES Journal of Marine Science published the paper of Chris Murray et al., which is the first of hopefully many publications of our experimental findings originating out of our new laboratory facility here at UConn Avery Point.
Chris and his co-authors report on a large-scale, quantitative rearing experiment on Atlantic silversides eggs, larvae and juveniles under contrasting CO2 conditions that took place between May – September 2015. This novel experiment was designed to address three critical issues lacking in previous ocean acidification research on fish. First, the study spanned several ontogenetic stages. Second, it used very large numbers of individuals to robustly characterize not just potential shifts in mean responses, but also changes in the distribution of length, weight, and condition factor. Third, it provided food at standardized, non-excess levels to prevent that potential metabolic costs of high CO2 exposure could be compensated by survivors simply by eating more food.
Overall the study demonstrated seemingly small but significant growth reductions due to high CO2 and identified a small number of fatty acids that were of significantly different concentrations in high vs. control juveniles.
This small conference brought together approximately 150 international scientists to talk about larval fish growth, survival, maternal effects, dispersal, systematics to name just a few. It was held in special honor of Edward Houde, who over his long career has inspired generations of marine scientists.
While Chris was presenting last years data about growth consequences of high CO2 exposure across life stages in our model species, the Atlantic Silverside, Hannes participated in the Early Career workshop and gave a talk about how to approach the writing of a scientific manuscript (PDF).
On 12 May 2016, the Department of Marine Science hosted it’s 11th Biennial Feng Graduate Research Colloquium, during which graduate students of the department traditionally present findings of their thesis research and/or give a preview of their future plans.
This year, Chris presented the results of last years study on long-term changes in growth distributions in Atlantic silversides exposed to high CO2 conditions, whereas Jake presented a poster outlining his thesis research on long-term environmental and biological data collected by Project Oceanology.
Gobler & Baumann’s review provides a good overview over the nascent field of multi-stressor acidification and hypoxia work. A first part firmly establishes that virtually all hypoxic zones in the ocean are also acidified, given that metabolic processes (i.e., respiration) consume oxygen and release CO2 into the environment. In a second part, the sparse emerging evidence for multistressor effects of low pH (high CO2) and low oxygen are reviewed, showing that while the majority of effects are additively negative, every study so far has also found synergistically negative effects of combined stressors in at least one trait.
Examples for synergistic negative effects of low DO and low pH (high CO2) on different traits and marine taxa. (a) Synergistic decrease in respiration rate in small and big sea urchins ; (b) growth rate of juvenile quahog was unaffected by low DO or low pH individually, but decreased under combined stressor conditions ; (c) survival of Atlantic silverside larvae to 10 dph. Survival was robust against low pH and sensitive to low DO, but decreased synergistically under combined stressors (green arrow, ); (d) representation of Po ̈rtners  ‘Oxygen- and capacity-limited thermal tolerance’ framework, adapted to the multiple stressor scenario of acidification and hypoxia.
There is increasing recognition that low dissolved oxygen (DO) and low pH conditions co-occur in many coastal and open ocean environments. Within temperate ecosystems, these conditions not only develop seasonally as temperatures rise and metabolic rates accelerate, but can also display strong diurnal variability, especially in shallow systems where photosynthetic rates ameliorate hypoxia and acidification by day. Despite the widespread, global co-occurrence of low pH and low DO and the likelihood that these conditions may negatively impact marine life, very few studies have actually assessed the extent to which the combination of both stressors elicits additive, synergistic or antagonistic effects in marine organisms. We review the evidence from published factorial experiments that used static and/or fluctuating pH and DO levels to examine different traits (e.g. survival, growth, metabolism), life stages and species across a broad taxonomic spectrum. Additive negative effects of combined low pH and low DO appear to be most common; however, synergistic negative effects have also been observed. Neither the occurrence nor the strength of these synergistic impacts is currently predictable, and there- fore, the true threat of concurrent acidification and hypoxia to marine food webs and fisheries is still not fully understood. Addressing this knowledge gap will require an expansion of multi-stressor approaches in experimental and field studies, and the development of a predictive framework. In consider- ation of marine policy, we note that DO criteria in coastal waters have been developed without consideration of concurrent pH levels. Given the per- sistence of concurrent low pH–low DO conditions in estuaries and the increased mortality experienced by fish and bivalves under concurrent acidifi- cation and hypoxia compared with hypoxia alone, we conclude that such DO criteria may leave coastal fisheries more vulnerable to population reductions than previously anticipated.
On 13 April, Hannes was invited to the board meeting of the Mumford Cove Association to present a brief update about our groups research activities in and around the cove. It is part of our commitment to public education and outreach to keep property owners informed and maintain good relationships with all parties involved.
The information material below contains graphical summaries of our activities, i.e., measuring water quality parameters continuously with a logging probe and conducting biweekly beach seine surveys for silversides.
On 15 March, Hannes gave a lecture at Mitchell College in New London, talking about the combined effects of ocean warming, acidification, and hypoxia on marine organisms. The entire lecture is publicly available at Limnology & Oceanography e-lectures.
“It was such a pleasure to have you present to the class today; your lecture was excellent – engaging with just the right amount and level of information. I’m glad that you intend to continue to provide outreach/education to the community on this topic.”