Ocean Acidification

[Lab news] Group effort – starting new silverside experiments in June 2017

It’s the beginning of June, and in the Baumann lab that means: high time for experimental research on the Atlantic Silverside, the famous forage fish and important model species! This year, we have several major objectives; our NSF-sponsored research examines the sensitivity of offspring to the individual and combined effects of high CO2 and low oxygen (Chris Murray), while in collaboration with our colleagues from Cornell University we rear several families for genetic and transcriptomic studies. Elle Parks, our REU student just started her work on the effects of CO2 and temperature on the starvation resistance of silverside larvae. As always, the days when new experiments start are a group effort, where everybody including many volunteers help. Thanks to Peter Morenus (UConn) for the coming down for documenting the activities!

This story is also featured on UConn Today.

[Field work] Our sand lance research in the news

NOAA sanctuaries just published a little blurb online, introducing sand lance and it’s importance to the Stellwagen Bank National Marine Sanctuary, including a small section on the current research efforts funded by NOAA Regional SeaGrant.

“To that end, the team is collaborating with scientists from the University of Connecticut (UConn). UConn study members transport live-caught sanctuary sand lance to their lab, where further generations of sand lance are raised. The resulting larval sand lance are raised in high-tech rearing facilities that can be adjusted to mimic future ocean conditions.”

Sandlance laughing gull
Seabirds, sharks, seals, whales and more rely on sand lance as a food source. Here, a laughing gull munches one of these eel-like fish. Photo: Peter Flood

The entire article can be accessed by clicking on the link below

[Field work] Sand lance spawning season has started

4th time’s the charm: sampling spawning ripe sand lance on Stellwagen Bank

On 2 Dec 2016, the sun rises over Scituate, MA, harbor and the fishing trawler that will take us to Stellwagen Bank this time.
On 2 Dec 2016, Chris waits for the action to start, while the trawler is leaving Scituate Harbor
sandlance embryos
Sandlance embryos, 24h after fertilization. The embryo stage in this species can be up to two months!
Early morning on 2 December 2016, we left Scituate, MA, for the forth time this year, heading towards Stellwagen Bank in search of spawning ripe Northern sand lance (Ammodytes dubius), a winter spawning forage fish of great importance to the Stellwagen Bank National Marine Sanctuary and the object of latest research efforts. While during the last three cruises in late October and November, we saw a progression of ripening in the specimens, up to now we didn’t actually find spawning ripe individuals. Today, though, things are different, and when the first sand lance appear in our beam trawl, we immediately know that today we’ve been at the right time and at the right place.
It seemed an ambitious dream not too long ago, but now we’re happy report that we’ve started an experiment on sand lance embryos in our lab. Thanks to Chris Murray, David Wiley, Mike Thompson, captain Steve and his deckhand Matt for the successful trip!
Early morning low tide at Scituate Harbor on 2 Dec 2016. The calm is deceiving; outside of the harbor the sea is pretty rough

Check out some footage of the trip and the beam trawl operation on board of captain Steve’s fishing vessel

[Field work] Catching sand lance on Stellwagen Bank

On 27 October 2016, Hannes, Chris and Julie joined researchers from the Stellwagen Bank National Marine Sanctuary (David Wiley, Anne-Marie Runfola, Brad Cabe, Michael Thompson), the USGS (Page Valentine, Dann Blackwood) and the crew of the R/V Auk (Dave Slocum, James Stasinos) to embark on our first of five total sampling missions in this enigmatic marine habitat. Our goal, catching live Northern sand lance, Ammodytes dubius, the so critical forage fish species that is referred to as the “backbone of the sanctuary”, because all kinds of marine predators from whales to tuna to seabirds gather on the bank to feast on them.

Our renewed efforts are part of our recently funded NOAA Regional SeaGrant Project to investigate the effects of ocean warming, acidification and low oxygen on sand lance early life stages.

As before, we first started by deploying a Seaboss sediment grab, which allows our colleagues from the USGS to characterize sediment types in association with the occurrence of sand lance. In addition, however, we brought a small beam trawl along for the first time to find out, whether we could more effectively catch sand lance and then transport them live to our seawater facility at UConn Avery Point. We are happy report that the efforts by all have paid off and that there are now ~ 180 adult ripening sand lance swimming in our tanks. Thanks all, see you again for the second survey in a few weeks!

Check out the video below, made from clips of no less than five different GoPro’s (if you listen carefully, around 2:40 into the clip you’ll hear the singing of some nearby humpback whales):

[New publication] Long-term growth consequences of acidification in Atlantic silversides

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.

Distributions of condition factor per 2mm TL interval for juvenile M.menidia reared for 122dph at control (a) and high CO2 conditions (b). Thick and thin black lines correspond to the 10th/90th and 25th/75th percentiles, respectively, while the red line depicts the median. Data below the 10th and above the 90th percentiles are depicted by black dots. Underlying grey bars show relative frequencies for each 2 mm TL class. Black and grey numbers correspond to numbers of individuals measured for both TL and wW, or for TL only, respectively.
Cumulative frequency distributions of (a) total length (TL) and (b) wet weight (wW), in juvenile M. menidia reared for 122 dph at control and high CO2 conditions.

Murray, C.S.*, Fuiman, L., and Baumann, H. (2016)
Consequences of elevated CO2 exposure across multiple life stages in a coastal forage fish.
ICES Journal of Marine Science (published online 10 Oct 2016)

[Opportunity] Summer Undergraduate Research Fund (SURF)

Seasonal dynamics in Atlantic Silverside abundance, spawning, and offspring sensitivity to low pH and oxygen

The Summer Undergraduate Research Fund (SURF) offers a summer stipend of up to $3,500 + $500 research. The Evolutionary Fish Ecology Lab offers a variety of suitable topics for undergraduates to work on.
Deadline for applications is January, 20th 2017.

How to apply: http://ugradresearch.uconn.edu/surf/#apply


NOAA announces funding for our research on sand lance

NOAA and Sea Grant fund $800,000 in research to understand effects of ocean changes on iconic Northeast marine life

The Ocean & Atmospheric Research program (OAR) of NOAA and Sea Grant just announced the winners of its most recent round of research funding to better understand the consequences of ocean warming and acidification on key marine resources in U.S. Northeast coastal waters. We are happy and proud that our proposed work on the climate sensitivity of Northern sand lance (Ammodytes dubius) was one of the four projects selected for funding. This is particularly good news for Chris Murray, who for his PhD can now expand his experimental rearing expertise to this important species.
This work will be conducted collaboratively with colleagues from NOAA (David Wiley), USGS (Page Valentine), Boston University (Les Kaufman), and Woods Hole Oceanographic Institution (Scott Gallager).

You can read the official announcement as it appeared on 6 September 2016 on NOAA’s News site.

Chris RV Auk Sediment grab
Chris Murray checking for sand lance caught by the sediment grab. RV Auk (Photo credit: Jacob Snyder)

[Lab News] The new silverside generation is here!

By Rafeed Hussain
On a balmy July 1st the lab returned to Mumford Cove excited at the prospect of seining without dawning waders for the first time this year! Chris and Rafeed conducted the first seine while Jake remained on the beach and photographed the experience. On the second seine, Hannes accompanied Rafeed while Chris weighed the first sample. As expected the species richness and diversity of the seines were less than that of previous excursions. The abundance of silversides was down, while their sex ratio was skewed towards females. Despite a decline in mature silversides, several juveniles were caught, indicating a budding cohort. Perhaps more young silversides will find their way into the lab’s net in the future. Only time will tell!

The first of 2016. On July 1st, the beach seine is catching a few 35 mm silversides – the new generation.

On 1st July 2016, Chris and Hannes look carefully through the bag of the beach seine to find the first juveniles of this year

[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

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.


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.

[Student video] Climate Change: A Future for Fish in a Changing Ocean

A big shout-out to Megan, Rainer, and Liz who apart from their intrepid work as volunteers in our lab also excelled here in their video project for MARN3000. They interviewed Profs. Kelly Lombardo, Michael Finiguerra, and Hannes Baumann about aspects of Marine Climate Change and then cut their answers with researched video material from the web. Note the sartorial touch throughout the clip (6 min)!
Well done, all!

Megan Barry
Rainer Moy-Huwyler
Elizabeth Karamavros