Publications & Presentations

[New publication] Biology Letters publishes CO2 x Hypoxia review

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.

This invited review was published Open Access.


Gobler, C.J. and Baumann, H. (2016)
Hypoxia and acidification in ocean ecosystems: Coupled dynamics and effects on marine life.
Biology Letters 12:20150976


Figure2---phxDO-examples
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 [27]; (b) growth rate of juvenile quahog was unaffected by low DO or low pH individually, but decreased under combined stressor conditions [23]; (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, [22]); (d) representation of Po ̈rtners [25] ‘Oxygen- and capacity-limited thermal tolerance’ framework, adapted to the multiple stressor scenario of acidification and hypoxia.

Abstract

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.

[Outreach] A busy year in Mumford Cove

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.

To a productive year 2016 in the cove!

Mumford Cove Ass_probe
Mumford Cove Ass_silversides

[Brown bag] Tips & tricks for preparing a good presentation

In preparation for the upcoming Feng Graduate Research Colloquium on Thursday, May 12 (Conn Avery Point, Marine Sciences), Hannes gave a brown bag seminar on how to make an effective presentation.

You can access/download the powerpoint of via this link below or by clicking on the image below.

Brown bag 4-13-16

[Lecture] OA multistressor lecture at Mitchell College

electure cover
Mitchell_College_email_logo_7_2015

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.”

Amy Cabaniss, Adjunct Faculty – Marine Ecology, Environmental Studies (STEM)

[Talk] Multistressor seminar at URI

URI talk

On 26 February 2016, H. Baumann was invited to give a seminar at the Biological & Environmental Sciences Colloquium Series at the University of Rhode Island, featuring the recently published e-lecture on “Combined effects of ocean acidification, warming, and deoxygenation on marine organisms”
His host, David Bengston has been a renowned fisheries and aquaculture biologist for the past 40 years.


Baumann, H. (2016)
Combined effects of ocean acidification, warming, and hypoxia on marine organisms.
Limnology and Oceanography e-Lectures 6:1-43

[e-lecture] Limnology & Oceanography publishes e-lecture on multistressors!

electure cover

A suite of parallel anthropogenic changes affects contemporary marine ecosystems. Excessive carbon dioxide (CO2) pollution results in warmer, more acidic oceans with lower dissolved oxygen (DO) levels, meanwhile the emission of reactive nitrogen/phosphorus results in eutrophication, excessive microbial degradation and thus metabolic hypoxia and acidification. Despite decades of empirical research how each individual stressor of the ‘climate-change syndrome’ (i.e., temperature, CO2, DO) affects the fitness of marine organisms, we still know little about the combined effects of these stressors. This lecture gives an overview over the nascent field of multi-stressor approaches evaluating the climate sensitivity of marine organisms across taxa. In most studied cases, combined effects of these stressors exceeded those observed individually. Effects of combined warming, acidification, and deoxygenation have mostly been additive (no stressor interaction) or synergistically negative (stressor interaction). The occurrence and strength of synergistic stressor interactions in some species, life history stages, and traits comprises a vexing challenge but hints at potentially greater sensitivities of organisms to marine climate change than previously recognized. This lecture is intended for post-secondary students, providing them with illustrated examples from the most resent literature, while aiding in communicating the urgent need for empirical data from multi-stressor approaches.


Baumann, H. (2016)
Combined effects of ocean acidification, warming, and hypoxia on marine organisms.
Limnology and Oceanography e-Lectures 6:1-43

[Talk] Future Ocean symposium (NYC) and the graphical recording of a presentation

Sustainable Ocean Development Symposium: A Perspective from Former, Current and Future Kiel Marine Scientists | September 28-30, 2015, New York City

H. Baumann gives invited lecture “Combined effects of ocean acidification and its co- stressors on marine organisms” at Columbia University

“I had no idea that ‘Graphical recording’ was a thing.

But Tracey Berglund, an artist currently living in NYC achieved with a whiteboard an a bunch of colored markers, what I wouldn’t have thought possible: a visually entertaining and remarkably accurate depiction of the main points of my talk, which highlighted the multistressor reality of climate change and the need for according experimental approaches.”

Head bowed, Tracey.”

See for yourself.

Graphical recording of H. Baumann's keynote lecture
Graphical recording of H. Baumann’s keynote lecture “Combined effects of ocean acidification and its co- stressors on marine organisms” (Artist: Tracey Berglund, tra4art.com)
Baumann - Future Ocean Conference
Hannes Baumann delivers remarks about effects of ocean acidification and it’s co-stressors on marine organisms
FutureOceans-group
Future Oceans Symposium at the Theological Seminary of Columbia University, NYC

[Presentation] H. Baumann talks at the 3rd Ocean Acidification PI Meeting in Woods Hole, MA

“Plastic and evolutionary responses to ocean acidification: navigating the difficult terrain between unfounded pessimism, optimism, and impossible tasks”

Woods Hole Oceanographic Institution, 11 June 2015

Experiments on contemporary marine organisms have demonstrated many negative responses to elevated CO2 levels, i.e., conditions that could occur in the average open ocean within the next 300 years. This has led to the recognition of ocean acidification (OA) as a key anthropogenic stressor and to concerns about detrimental changes to marine ecosystems on which humans depend. While assessing species sensitivities to OA has been the necessary first step, the gradual nature of these shifts further demands that we assess how transgenerational plasticity and evolutionary adaptation to OA will likely affect the overall vulnerability of species and ecosystems. Our predictive ability of these adaptive processes is still in its infancy.
Plastic & evolutionary responses to ocean acidification
The overview talk first looked at currently employed approaches to study adaptation, from relatively well-documented in vitro evolution to OA in single cell organisms to necessarily more inferential techniques (e.g., evolutionary potential, standing genetic variation, molecular techniques) in longer-lived metazoans where multi-generational experiments are largely unfeasible. Secondly, the talk touched on the likely role of transgenerational plasticity in mitigating adverse OA effects over shorter time-scales in some species and whether this could perhaps compromise their ability to genetically adapt. The final objective was to pose a number of largely unresolved questions (e.g., selection differentials? Evolutionary trade-offs?) and highlight a few, perhaps underutilized approaches (e.g., studying spatial gradients as analogies to temporal change) that might improve understanding of evolution and plasticity to OA.

The talk is publicly accessible on Prezi

[New Publication] Combining otolith microstructure and trace element analyses in Pacific bluefin tuna

A new study published in the ICES Journal of Marine Science suggests that analyzing the trace elements incorporated into the otoliths of bluefin tuna may allow inferring the arrival of juvenile fish in the California Current Ecosystem

Juvenile Pacific bluefin tuna (PBT, Thunnus orientalis) are known to migrate from western Pacific spawning grounds to their eastern Pacific nursery grounds in the California Current Large Marine Ecosystem, but the timing, durations, and fraction of the population that makes these migrations need to be better understood for improved management. This new study published in the ICES Journal of Marine Science suggests that analyzing the trace elemental composition of bluefin tuna otoliths may divulge the time of arrival of the juvenile fish on the Californian Shelf. Scientists from the University of Connecticut, Stony Brook University, Texas A&M, as well as from NOAA collaborated in this effort, hoping to further develop this method to better inform managers in the future.

Citation
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.
Free PDF and HTML access

[Campus Talk] H. Baumann talks at Avery Point Global Cafe

“Nets versus Nature: Have we indadvertedly made our fish smaller?”

Global-Cafe-talk

April 9th 2015. H. Baumann contributed to Avery Point’s Global Cafe Series “The Omnivore at Sea” by talking about the topic of fisheries-induced evolution.
When hearing and talking about sustainable seafood, issues such as overfishing, fishing-related habitat destruction (e.g., trawls tearing through bottom habitat, dynamite fishing) or changes to the architecture of marine ecosystems (‘fishing down the foodweb’) often come to mind. Baumann talked about another potential effect of heavy decade-long commercial fishing, which is less clear but perhaps even more insidious. Nature’s age-old rule of survival in the ocean, i.e., that faster growing fish have better chances of survival, is suddenly reversed when size-selective fishing becomes the dominant agent of mortality. Because in fishing, a faster growing fish will just be susceptible sooner to get caught by the meshes of a fishing trawl. We instinctively know that life on earth has adjusted before to changing selection pressures, and there’s little reason to suspect that this case might be different. Commercial fishing may trigger fisheries-induced evolution, and this may mean smaller, earlier maturing fish and less total biomass for centuries to come. The brief talk will summarize the problem as we know it, explore alternative explanations and look at examples, which show that the issue is also inextricably linked to all the other natural and man-made changes (warming, food web) that affect fish stocks. A cautionary approach that considers evolutionary processes within the framework of sustainable fisheries is surely warranted.