Author: Hannes Baumann

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

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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

Species or ecotype? The curious case of the Key silverside

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What constitutes a species …

…in the true sense has kept biologist’s head scratching for quite some time, and matters have only gotten more complex since the thunderous advent of genetic methods. Yet the distinction between a species and – say – an ecotype of a species is more than just academic quibble.

In the case of the key silverside, Menidia conchorum, a species that is only found in the hypersaline ponds on the Florida Keys, it’s quite literally an existential question. So far, the protocols and steps of protection apply only in cases of threatened species, which is perhaps something that ought to change.

O’Leary et al. went down to the Florida Keys and sampled the silversides in order to compare them morphologically and genetically to the ‘parent’ species, the tidewater silverside Menidia peninsulae. Their findings show that key silversides are distinct, but not quite their own species yet. In addition, the study revealed the large amount of inbreeding and genetic drift that is happening in each of these small hypersaline ponds.

The paper concludes that although ‘only’ an ecotype, the key silverside is threatened by loss of habitat and therefore still needs our protection!

O'Leary et al. BMS2016
Depiction of morphometric landmarks (upper left) and distinguishing shapes (lower left) between tidewater and key silverside (M. peninsula & M. conchorum). Key silversides are an ecotype that can only be found in hypersaline ponds on the Florida Keys (right: lead and co-authors seining).

O’Leary, S.J., Martinez, C.M., Baumann, H., Abercrombie, D.L., 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

[Lab News] Mumford Cove in December … an underwater view

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Roughly once a month, somebody from our lab has to hop on a small institute boat and drive the 20 min over to our local field site, Mumford Cove, to exchange the sensors on our monitoring buoy. Depending on water temperature, the Eureka Probes recording temperature, salinity, pH, and oxygen in 30 min intervals are getting exchanged with another newly calibrated one with a fresh set of batteries.
As usual, Jake’s seeing this a great occasion to bring his GoPro along and have a new underwater look at the cove. What’s interesting, the dense seagrass meadows that cover the Cove’s bottom have become spotty this time of the year, and there’s much more sand visible.

[Funding] New NSF OCE grant: 3 more exciting years of work!

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We are happy to announce the continued support of the National Science Foundation, Division of Biological Oceanography, which just started to fund our project about multi-stressor effects on the early life stages of fish. This is collaborative work with Prof. Janet Nye’s lab at Stony Brook University, NY, which will strengthen ties between UConn and Stony Brook Marine Sciences. The work has already started and we’re looking forward to new discoveries!

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 Project# 1536336 (3 years)

Learn more by accessing the NSF-OCE non-technical proposal abstract

[Lab news] Sand lance spawning

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For the last 6 weeks, we housed about 100 adult sand lance (Ammodytes dubius) in our lab that Chris and Jake brought from a research cruise on Stellwagen Bank (Massachusetts Bay). We watched them visibly ripen in our tanks, and today managed to strip-spawn 10 males and 10 females, obtaining several thousands of eggs and having them develop under different CO2 conditions now.
Thumbs up, and fingers crossed for the next steps!
Sand lance embryos 1h post-fertilization
Sand lance embryos 1h post-fertilization
Sand lance embryos 1h post-fertilization
Sand lance embryos 1h post-fertilization
Squeezing milt from a running ripe male sand lance
Squeezing milt from a running ripe male sand lance

Squeezing eggs from a running ripe female sand lance
Squeezing eggs from a running ripe female sand lance

[Field work] Catching spawning sand lance on Stellwagen Bank | 11-3-15

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

By Jacob Snyder:
Chris and I meet up, grab the supplies we need (buckets, bags, coolers, aerators, etcetera), and start making our way to Scituate, Mass. Today we are going out on the NOAA vessel “Auk,” with a few members from NOAA and the USGS. Our goal? To collect approx. 200 Northern Sand Lance, Ammodytes dubius.

We boarded the ship …

Read the whole post and see all the pictures on Jake’s blog @ Red Skies Photography

Check out the footage from the day, thanks to Jake and his GoPro. Check-out the video from the second sampling trip about one month later, too!

[Field work] Golden morning, Mumford Cove

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Golden fall morning at Mumford Cove. Picture-book conditions for beach seining with graduate and undergraduate students. Have a look for yourself (Picture credit: Sean Flynn, 9 Oct 2015)

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

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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

[Field work] Beachseining from the fish perspective

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On this golden-crisp early fall Friday morning (9-25-15), we went to our favorite spot again – Mumford Cove – to go beach seining. Thanks to the many helping hands – Chris, Jake, Elizabeth, Wes, Megan, and Hannes – we hand a ton of fun, while seeing a very diverse catch, among of course our target species – Atlantic silverside juveniles. These were measured on the beach and then preserved, and will ultimately become part of a larger study of the seasonal characteristics of survivors.

However, have you ever wondered what it must be like for fish to get caught in a beach seine. Well, thanks to Jake’s new GoPro and his ingenuity tethering it to the bag of the seine, here’s a glimpse (in HD). Enjoy!

Measuring and weighing the beach seine catch
Measuring and weighing the beach seine catch (f.l.t.r: Wes, Elizabeth, Megan, Jake, Chris)
A juvenile Northern Kingfish, Menticirrhus saxatilis
A juvenile Northern Kingfish, Menticirrhus saxatilis
Hermit crab needs new apartment
Hermit crab needs new apartment
Juvenile Winterflounder Pseudopleuronectes americanus
Juvenile Winterflounder Pseudopleuronectes americanus

Beach seining Mumford Cove 9-25-15

Elizabeth and Chris seining the Mumford Cove beach
Elizabeth and Chris seining the Mumford Cove beach

[Lab News] Laboratory silversides “becoming famous”!

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Sampling day! On September 15th 2015, our lab concluded a long-term growth experiment on four large laboratory populations (500+ fish per tank) of Atlantic silversides (Menidia menidia), which were reared at ambient and high CO2 levels and low temperature (17C) and feeding conditions. Given all the hard work rearing these fish from eggs to 4 month old juveniles, sacrificing them is always a bittersweet moment. To avoid the word ‘killing’, we therefore coined the euphemism “becoming famous”.

Thanks to Jake’s new GoPro, here’s a time lapse of all of us working for hours to sample, measure and preserve various parts of the populations for later analyses of weight, sex, as well as genetic and transcriptomic approaches.

Chris Murray measuring juvenile Atlantic silversides that were reared in our lab for the past four months
Chris Murray measuring juvenile Atlantic silversides that were reared in our lab for the past four months
Fish measurement party
Some fish were measured immediately, others were preserved in formaldehyde/seawater solution, frozen at -20C or -80C
Hannes Baumann measuring some the many fish that were sampled on 15 Sep 2015
Hannes measuring some the many fish that were sampled on 15 Sep 2015.