Field work

Max Zavell defends his PhD thesis!

 

18 April 2024. Today we are happy and proud to announce that Max Zavell has successfully defended his dissertation titled "Experimental assessment of ocean warming and acidification effects on multiple life stages of Black Sea Bass, Centropristis striata". A big, heartfelt congratulations from the entire lab!

Max Zavell had started as a PhD student in our lab in fall 2020, and his thesis research broke new ground by working experimentally with Black Sea Bass, a grouper species of great interest because of its recent, explosive increase in abundance in Long Island Sound and the larger northwest Atlantic shelf. Over two fall and winter seasons, Max conducted ambitious long-term rearing experiments on juveniles and adults to study how overwintering could be the key to understand these new dynamics. Now, after only three and a half years, Max has stepped up to the plate and showed his peers and colleagues the fruits of the work.

We were particularly delighted that all this committee members - Profs. Jacqueline Webb (URI), Catherine Matassa (UConn), and Eric Schultz (UConn) - were able to attend in person!

Well done, Max! Your team spirit and unwavering energy will be missed! We wish you all the best for your next career steps!

Max presenting
On April 18th, Max begins presenting his PhD research at UConn's Department of Marine Sciences

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Done! Max and Hannes savor a moment of pride in the Rankin Lab

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Max Zavell and Matt Mouland, who were a great team in the Rankin Lab and beyond

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Max with Hannes and Prof. Jacqueline Webb from the University of Rhode Island

Hannes returns from Chile!

 

16 April 2024. After a 9-month sabbatical stay at the University of Concepcion in Chile, Hannes returned to US soil today, full of experiences, data, and a chest full of samples of larval, juvenile, and adult Chilean silversides. Grateful to the many helpful colleagues and friends, a first year of experiments are in the bag, resulting in a number of interesting findings that await further analysis and - crucially - a second, replicate experiment in the year to follow. In other words, while the sabbatical is now over - the project of revealing co- and countergradient variation in the Chilean silverside is still very much underway. On to the next chapter!

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The cove of Puda near Dichato to the north of Concepcion, Chile

New 2023 sand lance experiment under way!

 

By Lucas Jones.

November 26, 2023. Members of the Sand lance Mafia assembled onboard the F/V Miss Emily in hopes of finding spawning ripe fish for our 2023 experiment. After loading our gear, Captain Kevin navigated us towards the southwest corner of Stellwagen Bank and deployed our beam trawl for our first 10-minute tow.

Boom! From the first tow, fish in spawning condition were brought on board, counted and separated by sex. Now, we just needed to repeat this for 13 more trawls until we had a sufficient amount of fish to start the experiment. After collecting 40+ spawning ripe males and females, we headed back to port wile starting to strip-spawn. This is an all hands on deck process, where we need to work together to evaluate the fish in real time and use the most ripe fish available.

The successful strip-spawn event now marks the start of our most ambitious experiment to date, where DNA and RNA samples will help us further investigate potential mechanisms behind the sand lances high CO2 sensitivity.

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Blastula stage sand lance embryos ~ 24h post fertilization

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The sandlance 2023 team after the first trip to Stellwagen Bank this year (left to right: Sam, Emma Siegfried, Chris Murray, Lucas Jones, Zosia Baumann, David Wiley)

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On 26 November, Lucas is back at the Rankin Lab with the goods!

UConn Today reports on Hannes’ Chile research

This article has been reposted from UConn Today. Read the original here

October 12, 2023 | Elaina Hancock - UConn Communications

Snap Shot: How Will Organisms Adapt to Climate Change?

A UConn Marine Sciences researcher is spending time in Chile studying an important forage fish, and how this vital part of the food chain will adapt to a changing climate

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The rocky and picturesque shores of the Pacific near Dichato

The world’s oceans have experienced record heat in 2023. With rising temperatures and increasing acidification, we don’t yet know the full extent these changes will have on marine ecosystems.

UConn Department of Marine Sciences Associate Professor Hannes Baumann studies fish, including important forage fishes such as sand lance and silverside, to see how they adapt to changes in environmental conditions. Many species are already adapted to temperature gradients that exist across latitudes on Earth, and Baumann believes that from these patterns, we can learn how fish may adapt to climate change – in time. This so-called “Space-for-Time” approach is one tool scientists use to predict the long-term consequences of climate change.

As part of his post-doctoral work, Baumann experimentally found similar climate adaptation patterns in Atlantic and Pacific silversides. He suspects that a higher-order relationship exists between the strength of adaptation and the strength of the underlying climate gradient.

Now, with a grant from the National Science Foundation, Baumann has the opportunity to return to and expand his study of silversides to a South Pacific species and study how they are adapted to their coastal latitudinal temperature gradient.

“We are hoping the prove the validity of a principle of evolutionary adaptation for the Southern Hemisphere. It will then allow us to compare and integrate the patterns with the silverside species from the Northern Hemisphere, which evolutionary ecologists have been studying for decades already,” says Baumann.

After a two-week proof-of-concept trip to Chile in the Fall of 2022, Baumann established connections with local fishermen and colleagues at the Universidad de Concepcion in Dichato, Chile.

“To get spawning fish, we visit fish markets – called here caletas de pescadores – and first establish a connection to those who make a living catching silversides (“pejerrey del mar”). We’re making friends to explain our unusual request to accompany a fisherman during the night. This is the best method to make sure that the eggs get fully fertilized," he says.

In the Summer of 2023, Baumann began his yearlong sabbatical and has now moved to Chile for five months to begin the main experimental work on Chilean silversides, their adaptations, and the strength of those adaptations to underlying climate change.

01 - HB-Tongoy
Hannes in Tongoy near Coquimbo/Chile

Hannes starts sabbatical research in Chile

17 Juli 2023. Hannes just moved for 5 months to a small village called Dichato near Concepción in south-central Chile to build and then conduct a large common garden experiment on the Chilean silverside Odontesthes regia.

It's still early, disorienting days - but thanks to the ever optimistic Mauricio Urbina, the collaborator on this project, the mood is good and full of anticipation.

Want to learn more? The Chilean silverside page has it.

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Sun over Dichato at Coliumo Bay on 22 July 2023

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Fishing boat in Dichato. In the background is the Marine Station.

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A dead purple sea urchin

Feeling the pulse of Mumford Cove

23 March 2023. For almost 8 years now, the Evolutionary Fish Ecology Lab has conducted research in nearby Mumford Cove, a small, eelgrass covered embayment on eastern Long Island Sound. Using a set of battery-powered probes we have continuously measured temperature, pH, oxygen, salinity, and depth in 30 min intervals in the Cove - almost 120,000 times. This ongoing effort is not funded by any grant or institution; instead, it has been sustained over all these years by the firm belief in the prescient, if undervalued societal service of monitoring, an activity without short-term reward but important long-term benefits in understanding how ecosystems change on short and long time-scales. To commemorate the effort, we simply thought that it is time to show you some data, some pictures, and draw some early, cautious conclusions about the very interesting case of Mumford Cove. Have a look!

Fig01---Mumford-Cove-sketch
Fig.1: Schematic section of the upper part of Mumford Cove, showing the deployed probe (blue) between the bottom anchor (grey) and a subsurface float (orange), marked by a surface float (white). The probe sits in the deepest part of the Cove (Channel), at constant 50 cm distance to the bottom, but variable water level above (red histogram).

"Future generations will certainly have better theories, tools, models, and computers, but they will still depend on the data and measurements taken here and now."

Aerial01
Aerial view of Mumford Cove (Picture: Jamie Vaudrey)

Fishing for silversides … in Chile!

A two-week stint to south-central Chile ends with a successful proof-of-concept that planned research on a Chilean silverside species will be highly feasible, opening avenues for a budding US-Chilean collaboration.

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Fishing boats in Caleta Tumbes near Concepcion, Chile

Concepcion (Chile), 12 October 2022. Two incredible weeks of adventure and scientific exploration for new and potentially groundbreaking science are coming to a close. In preparation for next year’s sabbatical, Hannes has met and made friends with colleagues at the Universidad the Concepción in southern Chile, travelled some 2,000 miles along the stunning Chilean coast, scoured local fish markets and accompanied artisanal fishermen on their nightly pursuits. The goal: finding a small fish that looks all too familiar – a silverside!

The Chilean silverside (Odontesthes regia), locally known as ‘pejerrey’, looks eerily similar to the Atlantic silverside (Menidia menidia), the model that has already inspired decades of eco-evolutionary research across many labs including ours. And like its northern hemisphere cousin, Chilean silversides occur over an astounding geographical range along the South American Pacific coast, all the way from Puerto Montt (42°S) to southern Peru (10°S)! There, average coastal temperatures change predictably with latitude and therefore provide a natural climate gradient in space that could serve as an analogue to climate change in time. Whether and how Chilean silversides show similar local adaptations to their latitudinal gradient is a big question – and next year’s sabbatical will start to provide some important answers.

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Pejerrey are usually caught with gillnets as here in the picture

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A Chilean silverside embryo of a few days post fertilization. Eyes beginning to pigment and a prominent yolk artery provides nutrients for growth

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A Chilean silverside embryo close to hatch

To prepare, Hannes spent two weeks in September and October 2022 in Chile. Hosted by the ever-enthusiastic Prof. Mauricio Urbina from the zoology department and thanks to a visiting grant from the university, we were ready to start exploring. Our specific goal for this trip was to find spawning-ripe pejerrey in two of the planned four locations along the coast.

The luck was on our side and the timing of the visit turned out to be perfect. On a nightly fishing trip with the artisanal fisherman Juan Figueroa from the small village of Tumbes near Concepción, we caught running ripe males and females, observed naturally deposited egg masses in nearshore waters, and were able to subsequently document the temperature-dependent development of newly fertilized embryos.

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Left: During spawning season, pejerrey deposit enormous masses of eggs on vegetation in shallow water. Right: The Marine Station of the Universidad de Concepcion in Dichato

On an epic road-trip up the coast all the way to Coquimbo, Hannes and graduate student Rocio Barrios stopped at many villages and local fish markets, gathering information and finally securing precious samples of spawning-ripe pejerrey from a fisherman at the Coquimbo fish market. Transporting the embryos was a success, too, thereby paving the way for the proposed research plan next year.

The real, big common garden experiments will take place from September – December 2023 at the Dichato Marine Station near Concepción, a small but recently renovated station with excellent facilities for our purposes.

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On the road during our trip to Coquimbo

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Beautiful spring at the scenic Coliumo Bay near Concepcion

While at the University, Hannes also gave a seminar talk to the students and faculty explaining his excitement and plans for coming to Chile, which received great interest, curiosity, and students expressing interest to play a part in this.

    Baumann, H. 2022. Principles of local adaptation across environmental gradients (or: why I’m so darn interested in studying Chilean silversides). Invited seminar talk. University de Concepción, 29 Sep 2022

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A gillnet used to fish for Chilean silversides on the beach of Tumbes near Concepcion

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A newly hatched Chilean silverside measuring already an astounding 9 mm TL


John and Hannes travel to Bermuda to install a new CO2 system

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The Bermuda Institute of Ocean Sciences (BIOS) with its flagship the R/V 'Atlantic Explorer' in May 2022

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John Hamilton (right) and Hannes Baumann (left), the UConn team for the BIOS CO2 project

29 May 2022. When in a few months researchers and students at the Bermuda Institute of Ocean Science (BIOS) begin using their new outdoor mesocosm facility, they can now manipulate and control the CO2 levels in as many of 9 flow-through basins. The important new capacity of the system will allow realistic ocean warming and acidification experiments and has been the product of a wonderful collaboration between BIOS researcher Dr. Yvonne Sawall and our UConn Marine Sciences team consisting of John Hamilton and Hannes Baumann.

The newly developed system shares some of the design ideas with ALFiRiS, the factorial rearing system we developed and used over the past years at UConn's Rankin Seawater Lab. For example, we again developed and installed a central pH measurement hub that sequentially collects water samples via pumps from each of 12 independent basins, which is advantageous, because it only relies on a single, high-end pH sensor, therefore making measurements always comparable. Similarly, we are using LabView software (National Instruments) to switch pumps on and off and log, display, and graph the pH conditions in real time for researchers to have confidence in their chosen environmental parameters.

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A view over Mullet Bay from Slip Point Lane in St.George/Bermuda

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A downward view of BIOS' outdoor mesocosm facility, still in the middle of the major refurbishment

While most of the planning and design work was done remotely via frequent online meetings, Hannes and John worked with Yvonne during the past week at the BIOS station on installing and testing the systems major components. Working mostly out in the open under a warm and clear Bermudan sky was a particular treat of this assignment. Big shout-out, too, to facilities manager Kevin Hollis for his tireless onsite help!

Despite setbacks in form of supply chain delays and an unfortunate last moment COVID infection preventing team member Lucas Jones from traveling to Bermuda, soon the new outdoor mesocosm facility at BIOS will become operational and allow new and advanced kinds of experimental research on global change biology.


Staying at the Mary and James Buttler suite at BIOS was a particular treat

ElectronicsBox
The electronic box designed & assembled by John controls the sampling pumps

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On May 24th, John is explaining the workings of the software to Yvonne and Roderick

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On May 26, Yvonne measures pH in a mock-up of the CO2 header tanks for the mesocosm facility

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On May 28, our work is done and we enjoy the evening on the dock of Yvonne's place in St.George

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'Winky' is the queen of BIOS

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The R/V Atlantic Explorer is the flagship of BIOS and the main operation platform for the BATS time series

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John takes a picture of a Royal Poinciana (Delonix regia, Fabacea, Caesalpinioideae), a particularly stunning tree at the BIOS and all over Bermuda

Another crazy road trip for genetic silverside research

15 May 2022. A full, blood red moon rises over Pine Island this Sunday evening. The sight makes not just humans swoon – its pull extents underwater to all kinds of critters that take it as cue for reproduction. Critters just like the Atlantic Silverside, which once again we pursue this season to extract more of its genomic 'secrets'.

Specifically, it is this weekend that we embark on yet another ambitious road trip to find and sample spawning-ripe silversides from two very far apart places: Morehead City, North Carolina and Beverly, Massachusetts. The goal: transport spawners live from each population to UConn's Rankin Seawater lab and produce calculated crosses that will allow studying the role of genomic inversions in local adaptation.

The crew this time are Maria Akopyan and Jessica Rick from Cornell University, along with Lucas Jones and Hannes Baumann from UConn. Big shout-out to Tara Duffy for her help with beach seining at Beverly, MA. During the spawning event on May 15th, Nina Therkildsen also joined the efforts. The design and experiment are part of Jessi's successful NSF post-doctoral fellowship proposal, which the whole UConn-Cornell silverside team supports.

Click through the pictures below to retrace the steps of an exhausting but so far successful effort. Fingers crossed that all goes well during the next weeks, when the fish need to hatch, survive and grow, so they can be assessed for their traits.

Map-trip
The US east coast map illustrates our ambitious sampling plan.

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On 12th May, fog envelopes the Chesapeake Bridge on our drive south to Morehead City, NC.

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Maria, Hannes, Lucas, and Jessi getting ready to beach seine the Morehead City site

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Our 100ft beach seine is being laid out on the Morehead City site.

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On May 13th, Atlantic silversides caught in Morehead City swim in a bucket.

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Lucas checking whether the fish are properly prepared for transport.

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Ripe adult silversides are being transported in large coolers, with proper aeration and water changes underway.

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Maria driving through the night. The long trip back up north is especially taxing.

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On May 14th, Jessi and Tara pull our seine net up the beach on Obear Park, Beverly, MA.

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Maria bringing a new sampling bucket to Jessi and Tara (background) seining.

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Seining at low tide in Obear Park is made more difficult by ankle deep mud.

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On May 15th, at UConn's Rankin Seawater lab, Nina and Jessi strategize about designing crosses.

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On May 15th, Hannes, Jessi, and Nina spawn individual silversides.

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Jessi squeezing a silverside female for eggs in UConn's Rankin Lab.

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A 24 hours old silverside embryo developing at 26C.

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On May 15th, Jessi lays out individual crosses to be reared in the circle tanks in UConn's Rankin Lab.

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Nina and Maria extract DNA from male and female spawners to determine a specific regions homo- vs. heterozygosity.

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Screens with attached embryos are being suspended in buckets for development under two different temperatures.

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A specific capture probe (TARMS gel) allows the quick determination whether adult spawners were homo- or heterozygous for specific inversions on chromosomes 11, 18, or 24

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A silverside larva 6 days post hatch produced from NC spawners. The stomach is full of brine shrimp nauplii, pigmentation just started.

Unveiling a new sturgeon outreach sign at Hammonassett State Park

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On May 7th, project members, CTDEEP, and CT SeaGrant representatives unveil the new outreach sign about Atlantic sturgeon at Hammonassett State Park (f.l.t.r. Mason Trumble, CTDEEP deputy commissioner; Tom Savoy, CTDEEP scientist; Kelli Mosca, CTDEEP; Joe Cunningham, CTDEEP; Hannes Baumann, UConn; Sylvain Deguise, CT SeaGrant Director; Jacque Benway, CTDEEP

May 7th, 2022. Despite the chilly, rainy weather on Hammonassett Park's Meigs Point and the resultant lack of a beach crowd, the mood among the group was elated and proud. For over two years, our lab together with researchers from the Connecticut Department of Energy and Environmental Protection (CTDEEP, Tom Savoy, Jacque Benway) have worked tirelessly to better understand the growth and seasonal movement patterns of Atlantic Sturgeon (Acipenser oxyrhynchus) in Long Island Sound and the Connecticut River. The research project was funded by Connecticut SeaGrant (NOAA Award NA18OAR4170081, Project R/LR-29).

Kelli Mosca did her M.S. thesis research using fin spine sections for growth analyses and telemetry data for movement patterns. After defending in March 2022, she immediately accepted an offer by CTDEEP to become a full time staff scientist. Congrats again, Kelli!

The sign was designed by Joe Cunningham with pictures from Jacob Snyder (RedSkiesPhotography.com). It combines several outreach goals. 1) Convey to people that these ancient, iconic fish actually occur in our waters, 2) teach the interested readers that sturgeon spawn in freshwater and then grow up in saltwater, 3) give readers a sense of the ongoing research on Atlantic sturgeon, 4) tell the public that sturgeon may come back to Long Island Sound and River, but need protection. Particularly, they rely on any accidental catches to be released and reported. The sign is also available in Spanish language to broaden its reach.

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The sturgeon outreach sign at Hammonassett State Park