Talks

A Day on the Ocean

Posted on June 6, 2024June 6, 2024 by Hannes Baumann

20 May 2024. Who wouldn't want to trade the confines of a highschool classroom for a day on the ocean, particularly one packed with whales, dolphins and seabirds? On this Monday in May, 60 seniors of the Marine Magnet Highschool in Groton, CT and the Plainfield Highschool in Plainfield, CT were indeed lucky enough to enjoy such exceptional experience and a very special class out on the water.

Because this was no ordinary whale watch. Our team from the NSF-funded sand lance project (Hannes, Zosia, Lucas, and Emma) accompanied the highschoolers and together boarded the "Tails of the Sea" (Captain John Boats, Plymouth, MA). While the vessel navigated the route to the Stellwagen Bank National Marine Sanctuary, Zosia, Emma and Lucas assembled small groups of students to tell them more about what extraordinary fish sand lance are, why they are so important, and why ocean acidification may be a troublesome issue for these forage fish.

Emma and students — On 20 May 2024, Emma Siegfried explains the importance of sandlance to highschool students

What we hoped but couldn't have known for sure: nature spectacularly cooperated with our curriculum. We observed large numbers of minke, fin, and humpback whales as well as a large pod of Atlantic white-sided dolphins chasing schools of sand lance all around the ship, while gannets, seagulls and terns were trying to get their share of the feast from above. Mesmerized, nobody could get away without learning the central lesson of this day. Sand lance are the backbone of the Stellwagen Bank National Marine Sanctuary, and there are still too many things we do not know about these fish.

Lucas and students — Lucas Jones introduces Stellwagen Bank to students of the Marine Magnet Highschool in Groton, CT

A strong showing at the 47th Larval Fish Conference!

Posted on May 18, 2024May 18, 2024 by Hannes Baumann

17 May 2024. Members of our Evolutionary Fish Ecology Lab had a blast attending this years 47th Larval Fish Conference in Huron, OH. Hannes, Emma, Max and alumnus Chris Murray (now at WHOI), went on a road trip from Connecticut to Lake Eerie to present and learn about all things larval fish. On Tuesday morning, the conference crowd enjoyed excursion or recreation options, all the while catching up with good old colleagues and making new connections and friends. A particular achievement: each of us presented research on a different fish species; while Hannes showed the first data emerging from his sabbatical research on Chilean silversides, Emma talked about baby California grunion development. Max presented a poster and two talks, the first about CO₂ effects on the onset of schooling in Atlantic silversides and a second one one Black Sea Bass overwintering dynamics. Last, Chris Murray gave a fascinating first look into gene expression data from our most recent sand lance CO₂ experiment. All around, a strong showing of our lab!

Contributions from our lab to the 47th Larval Fish Conference in Huron, OH

Baumann, H., Gallardo, A., Gallardo, C., and Urbina, M. 2024. First evidence for countergradient growth variation in the Chilean silverside Odontesthes regia. Oral presentation

Siegried, E. and Johnson, D. 2024. Eyes bigger than your stomach: developmental inaccuracy in larval California grunion. Oral presentation.

Zavell, M.D., Mouland, M., Barnum, D., Matassa, C., Schultz, E.T., and Baumann, H. 2024. Overwintering dynamics of northern stock Black Sea Bass, Centropristis striata, juveniles. Oral presentation.

Zavell, M.D., O'del, J., Mouland, M., Webb, J.F., and Baumann, H. 2024. Ontogeny of larval schooling and effects of ocean acidification in Atlantic Silversides (Menidia menidia). Oral presentation.

Murray, C.S., Jones, L., Siegfried, E., Zavell, M.D., Baumann, Z., Wiley, D., Therkildsen, N., Aluru, N., and Baumann, H. 2024. Examining the effect of ocean acidification on hatching enzyme gene expression in Northern sand lance (Ammodytes dubius). Oral presentation.

Hannes & Max at the 45th Larval Fish Conference in San Diego

Posted on September 7, 2022September 13, 2022 by Hannes Baumann

2 September 2022. After two grueling years of pandemic restrictions, Zoom conferences and meetings, the Baumann lab was as elated as anyone else to attend the first in-person conference again! Hannes & Max went to beautiful La Jolla in San Diego to participate in this years 45th Larval Fish Conference (Aug 29 - Sep 2). The stunning setting of the Scripps campus amidst the sound of the Pacific Ocean breeze provided the right kind of backdrop to again mingle with colleagues, meet fellow graduate students for scientific and just fun discussions, while an eclectic number of talks across the spectrum of Larval Fish and Larval Biology renewed the inspiration for our science. Hannes gave a keynote about our recently published work on sand lance CO₂ sensitivity, while Max presented his first conference talk about juvenile Black Sea Bass growth and energy allocation.

A big, heartfelt thanks to Noelle Bowlin (NOAA) and her team for pulling off this remarkable conference during these still uncertain, post-COVID times!

World Ocean’s Day at 3rd grade Groton Elementary School

Posted on June 21, 2022June 21, 2022 by Hannes Baumann

7 June 2022. This is World Ocean Week and many Marine Science students and faculty do their bit to increase outreach to our community. Hannes had the privilege of dropping by the 3rd graders of the Catherine Kolnaski Magnet School, talking about what Marine Scientists do, which ocean critters eat another and "What was the weirdest fish you ever caught?" Oh, and "Are you really sure that the Megalodon [Charchardon megalodon] is no longer alive?" Thank you to Mr. Moon, Mrs. Laudone for the opportunity to come visit the school!

Kelli Mosca presents Master thesis research on Atlantic Sturgeon

Posted on March 21, 2022March 23, 2022 by Hannes Baumann

21 March 2022. Today, Baumann lab graduate student Kelli Mosca presented her Masters thesis entitled "Atlantic sturgeon (Acipenser oxyrinchus) Growth and Habitat Use in the Connecticut River and Long Island Sound". She did a marvelous job summarizing the multifaceted findings on age and growth of Atlantic sturgeon in the eastern Long Island Sound and the Connecticut River, their movement patterns based on analyses of acoustic telemetry data, while evaluating the evidence for indications that Atlantic sturgeon may utilize the Connecticut River again for spawning.

Kelli was an inspirational and cherished member of the Baumann lab, who literally mastered the challenges of being a 'whole-pandemic' Master student. Her dedication and continued work for CTDEEP were awarded by an offer for a CTDEEP Fishery Biologist I position, which she has wholeheartedly accepted. Congratulations Kelli, and all the best for the next steps in your career!

The UConn Department of Marine Sciences
Presents a Master’s Thesis Presentation by

Kelli Mosca
B.S., University of New Haven, 2017

12:00 p.m., Monday, March 21, 2022
Lowell Weicker Building, Seminar Room 103 or Via WebEx

**Atlantic sturgeon (Acipenser oxyrinchus) Growth and Habitat Use in the Connecticut River and Long Island Sound**

Atlantic sturgeon (ATS, Acipenser oxyrinchus) are long-lived, anadromous, and endangered fish with a wide geographical distribution along the east coast of North America. Historically known to spawn in numerous rivers, many spawning runs ended due to intense fishing pressure and habitat obstruction in the 19th and 20th centuries. This was thought to be true for the longest river in the US Northeast, the Connecticut River, until pre-migratory ATS juveniles appeared in the river in 2014. Here, I use a long-term archive of fin spine samples and three years of acoustically tagged ATS to generally expand knowledge about the ATS using the CT River and LIS, and specifically examine these empirical data for potential evidence of re-emergent spawning behavior. I analyzed 301 sections of ATS fins spines collected from 1988-2021 to determine age, annuli widths, and thus population- and individual-based growth patterns. I found that the vast majority of ATS in my study area were juveniles and sub-adults with an average (± SD) age of 7.5 ± 3.1 years and an average (± SD) length of 101 ± 26 cm. The weighed, population-based Von Bertalanffy growth model estimated a K of 0.08 (95% CL, 0.01/0.17) and a L∞ of 171.2 cm (95% CI, 129/547 cm), the latter likely showing signs of missing large adults. K and L∞ distributions showed no sign of sex-specific multi-modality. Longitudinal length back-calculations revealed the selective disappearance of faster growing phenotypes (at ages 2-6) with increasing age at capture, which is clear evidence for Lee’s phenomenon. Acoustic detections of telemetered Atlantic sturgeon (2019-2021) revealed that most sturgeon in 2019 and 2020 utilized the Lower CT River (brackish water), whereas in 2021 detections were highest in LIS (salt water). Detections in the Upper CT River (freshwater) were common but much less dense across years, with 53%, 69% and 45% of ATS detected in the Upper CT River at some point in each season (2019-2021 respectively). I found a positive relationship of fish proportion in the CT River with temperature, but an inverse relationship of fish proportion in the CT River with river discharge. On average, the arrival of fish in the CT River occurred in June, when water temperatures were 17.5 - 24.9 ºC, while the departure from the CT River generally occurred in October, coinciding with river temperatures of 15.2 - 20.4 ºC. Some of the fish utilizing the Upper CT River made directed movements to a potential spawning ground at Portland, CT (river km 47). However, these movements occurred in mid- to late August (12th -23rd), which is inconsistent with the typical spring timing of ATS spawning runs in northern populations. Fall spawning runs are only known for southern ATS populations. In addition to timing, ATS sizes in the Upper CT River also do not support spawning behavior, because fish of all sizes (72 – 154 cm TL) and ages (3-15) visited the Portland area for 0.25 – 63.25 days. I conclude that neither age nor telemetry data support the re-emergence of the CT River as an ATS spawning ground. Future work will benefit from a more even sampling of gear sizes and should examine possible explanations for ATS freshwater utilization including feeding and individual preferences.

Major Advisor: Hannes Baumann
Associate Advisor: Eric Schultz
Associate Advisor: Tom Savoy
Associate Advisor: Jacque Benway
Associate Advisor: Catherine Matassa

Hannes gives DMS Friday seminar on sand lance ecology

Posted on March 4, 2022March 4, 2022 by Hannes Baumann

4 March 2022. Hannes was the invited speaker at today's Friday seminar of the Department of Marine Sciences. His talk gave an overview of the research highlights of our multi-disciplinary and multi-institutional efforts to better understand basic ecological facts, population connectivity & structure, and the unusually high CO₂-sensitivity of sand lance embryos. The remotely given presentation was attended by 62 people, some of which listened in from as far away as Norway!

The talk was recorded and can be accessed via the public link below.

Baumann, H. 2022. The unusual ecology & climate sensitivity of sand lance, a key forage fish on the Northwest-Atlantic shelf. UConn Marine Sciences Friday seminar. Online. 4 March 2022.

The unusual ecology and climate sensitivity of sand lance, a key forage fish on the Northwest-Atlantic Shelf

No matter how you look at these small, slender-bodied fishes that at times live buried in sediment or emerge as dense pelagic schools, northern sand lance (Ammodytes dubius) easily awe even the most hard-to-impress scientist or naturalist. Their unusual behavior, patchy occurrence, and reproductive timing are paralleled by their extraordinary importance as forage fish that sustain well-known hotspots of iconic predators (cod, tuna, sharks, seabirds, whales) all across the Northwest Atlantic shelf. And yet, despite their recognized role as the ‘backbone’ of many shelf ecosystems, we still don’t understand many basic aspects of sand lance ecology, population structure and their vulnerability to manmade climate change. Over the past years, our lab has been working alongside other US and Canadian research groups on multiple sand lance projects that have produced stunning new insights into these enigmatic fish. This seminar will outline some of the highlights. We discovered that the seasonal growth of these fish relies heavily on the lipid-rich copepod Calanus finmarchicus and showed that after a dormancy period in summer they spawn on Stellwagen Bank for just a brief period at the end of fall. To resolve questions of connectivity between sand lance areas, we performed large-scale Lagrangian drift simulations that suggested areas of high, low and negligible retention of sand lance offspring and showed overlaps with planned offshore wind lease areas. A large collaborative effort succeeded in obtaining specimens from across the entire distributional range (Greenland to Mid-Atlantic Bight), and subsequent whole genome sequencing newly revealed a stark genomic differentiation between northern and southern population clusters. Last, we performed multiple years of rearing experiments on embryos that consistently showed an unusual sensitivity of sand lance to future, high CO₂ oceans. When coupled with regional, end-of-century pCO₂ projections we estimate that rising CO₂ levels alone could reduce sand lance hatching success to 71% in 2100 relative to today. Warming, acidification, and habitat exploitation therefore emerge as key factors lining up against the future productivity of this forage fish, which is so critically important across Northwest-Atlantic shelf ecosystems.

Video: A November day on Stellwagen Bank

Lucas Jones presents his Masters Thesis research!

Posted on November 27, 2021November 27, 2021 by Hannes Baumann

The UConn Department of Marine Sciences

Presents a Master’s Thesis Presentation by

Lucas Jones

B.A., University of Connecticut, 2018

4:00 p.m., Monday, November 22, 2021

Marine Sciences Building, Seminar Room 103

**Using Low-Coverage, Whole Genome Sequencing to Study Northern Sand Lance (Ammodytes dubius) Population Connectivity in the Northwest Atlantic**

Northern sand lance (Ammodytes dubius) are key forage fish in Northwest Atlantic (NWA) shelf ecosystems, where they exclusively occur on coarse-grain, offshore sand banks. This patchy occurrence may result in genetically more fragmented, less connected populations, but traditional morphological or genomic approaches have so far been unsuccessful in fully resolving the species’ population structure and connectivity. My study pursued an alternative genomic approach, using low-coverage, whole genome sequencing (LcWGS) to address these important questions. I extracted DNA from 273 A.dubius specimens collected by collaborators from sevenregions across the species geographical range, from Greenland to New Jersey, USA. From LcWGS data, I identified 11,558,126 single nucleotide polymorphisms (SNPs) that allowed quantifying genetic differentiation between populations (F_ST), thereby revealing the genetic structuring of populations throughout the NWA. Despite the potentially homogenizing influence of the general north to south ocean circulation, I found a clear genetic break around Nova Scotia that delineated a northern from a southern A. dubius supergroup. Only within the southern supergroup, genetic distances increased with the geographic distance between sample sites. At the focal site of Stellwagen Bank (southern Gulf of Maine), A. dubius samples collected over several years (2014 – 2019) revealed small but significant temporal genetic differences that imply varying occupation of this offshore habitat by genetically different sand lance contingents. Inclusion of samples from the inshore congener A. americanus confirmed the clear genetic separation between both species and further determined that all sand lance caught on Stellwagen Bank are exclusively A. dubius. Overall, my work suggests the existence of two spatially distinct A. dubius populations with little ‘realized’ connectivity, which is critical knowledge to aid protection and management of offshore marine resources.

Major Advisor: Hannes Baumann

Associate Advisor: Nina Overgaard Therkildsen

Associate Advisor: Senjie Lin

44th Larval Fish Conference held virtually 24-26 June

Posted on July 3, 2021July 3, 2021 by Hannes Baumann

Groton, CT 24-26 June 2021. The long awaited and anxiously prepared virtual 44th Larval Fish Conference was held, featuring more than 240 participants from 28 countries. 58 scientific talks, including 3 keynote lectures were given via Cisco’s WebEx platform, whereas networking activities such as poster presentations, ‘Meet the Speaker’ events, and Mentor hours used the innovative Gatherly platform. The technology was working out well, the preparation paid off, and delegates were overall enthusiastic about this virtual alternative, which was forced on us by Covid-19, but may have shown us new ways and concepts to broaden the societies reach and equality.

The post-conference website is housed at https://lfc44.marinesciences.uconn.edu

Special thanks go to the scientific steering committee Eric Schultz, Jacqueline Webb, and Paul Anderson. Lauren Schaller, Anne Hill, Harley Erickson, and Kate Copeland from UConn’s conference services did a great job as well preparing and running parts of the events. Support came from NOAA’s Northeast Fisheries Science Center.

‘Hooked on OA’ – Hannes talks about fish CO2 sensitivity to recreational anglers

Posted on March 1, 2021March 1, 2021 by Hannes Baumann

25 February 2021. The Mid-Atlantic Ocean Acidification Network (MACAN) organized a four-part webinar series on Ocean Acidification geared specifically towards recreational anglers and shellfish collectors in the Mid-Atlantic region. The series is called “Hooked on OA” and invited Hannes on this February Thursday to explain the state of OA science particularly for fishes. A big thanks to the organizers and the more than 50 people who participated in this webinar.

If you missed it and are still interested, you can watch the Zoom webinar here:

[Lab news] Hannes & colleagues organize a Virtual Town Hall

Posted on June 29, 2020June 29, 2020 by Hannes Baumann

23 June 2020. It’s been a remarkable day. A remarkable few months of preparation. But on this Tuesday in June, more than 250 people from all over the world logged in to a UConn WebEx Event organized by Hannes Baumann, Eric Schultz, Jacqueline Webb, Paul Anderson and Jon Hare. The event, billed as the “1st Virtual Larval Fish Science Town Hall” was of course a product of the strange and challenging times we live in right now. A consequence of almost a year of painstaking preparations for the 44th Larval Fish Conference in Mystic, CT … eclipsed by the COVID-19 pandemic that made having a physical science conference impossible.

Attendance-graph — Number of attendees per minute throughout the day. Science sessions were followed by 120-170 attendees worldwide.

The Virtual Town Hall gave 16 speakers from around the world the opportunity to communicate their science, while providing a forum for the community to interact. The Early Career Committee of the AFS Early Life History Section contributed as well, organizing a round table discussion led by Kelsey Swieca with Chris Chambers, Jackie Webb, and Peter Konstantidinis. Individual networking meetings – although hobbled initially by technology – were held after the meeting between senior and early career researchers.

And best of all – more than 40 people participated in a picture contest, contributing stunning images of larval fish or larval fish science.

For more information, speaker bios’s, talk titles, abstracts and even some video please visit the event website lfc44.uconn.edu

Some of our personal favorites among the best larval fish picture submissions

A35---Bartick---Ribbonfish-fb-1-of-1 — Mike Bartick | Ribbon fish

A32---Meldonian---Cyclopsetta-fimbriata-7-8-19-9932-final — Irene Middleton | A diver checks out a juvenile flying fish at the Poor Knights Islands in New Zealand

A25---Parkinson--29354-004-Molidae-A — Winner – Kerryn Parkinson | Mola sp – a larval sunfish collected off New South Wales, Australia.

A23---Monteiro---Tilefish_CNamiki — Gabriel Monteiro | Caulolatilus chrysops larvae cleared and stained. This specimen belongs to ColBIO USP biological collection.

A15---Walsh---larval-Bothus_20170615_photo-by-Har — Harvey Walsh | Bothus larvae sorted at sea from a bongo net tow collected during the summer of 2017 aboard the NOAA Ship Gordon Gunter.

A10---Murray---Pacific-Herring-embryo — Chris Murray | Wild Pacific herring spawn from Skagit Bay, WA (~72 h old). Note the flat edge of the egg where it was adhered to sea grass.

A05---Grande-H.-Acanthurus-coeruleus — Henrique Grande | Post-larval reef fish Acanthurus coeruleus Bloch & Schneider, 1801 collected in 2015 using light traps in the Bay of Tamandaré, Brazil.