Research

UConn Researchers Deploy Innovative Seafloor Lander in the Arctic

By Cloé Mueller.

20 October 2026. This summer, researchers from the Broadband Acoustic Lab (BAL), led by Dr. Liz Weidner in UConn's Department of Marine Sciences, successfully deployed a seafloor lander in the Arctic to study changing ocean conditions in a glacial fjord.

The lander, a triangular aluminum platform equipped with advanced acoustic instruments, was deployed in Hansbukta, a glacial bay within Hornsund Fjord in southwest Svalbard. The scientific team included Dr. Weidner, BAL Ph.D. student Cloé Mueller, and Dr. Tom Blanford from the University of New Hampshire.

Echosounder equipment on a ship
Seafloor lander aboard the M/V Ulla Rinman prior to deployment in Hansbukta, Hornsund Fjord, Svalbard, with the Hansbreen glacier terminus visible in the background. The acoustic system on the lander consists of a WBAT and two high-frequency broadband echosounders.

Team of researchers on a research vessel
The scientific team from left to right: Dr. Tom Blanford, Dr. Liz Weidner, and Cloé Mueller.

Positioned ~55 meters below the surface, the lander uses upward-looking sonar systems to continuously monitor the water column above it. These acoustic observations will be used to investigate ocean structure, sea ice conditions, and mixing processes in the fjord throughout the year.

The team successfully recovered the instrument one week after deployment, obtaining an initial acoustic dataset th­­­­at will help validate the system and guide future analyses. The lander was then redeployed for a full year of observations and will be recovered during a return campaign next summer. The year-long record will provide an unprecedented view of how polar ocean conditions evolve across seasons, including during the winter months when the fjord is inaccessible for fieldwork.

A map of the study site in Svalvard
The field campaign site in Hansbukta bay of Hornsund Fjord, Svalbard. The yellow star marks the seafloor lander deployment site. The navy line illustrates the terminus extent of Hans glacier in July 2026. Solid cyan, pink and red lines denote three acoustic survey collection transects: 1) lander cross (red), 2) along and across fjord (cyan), and 3) glacial scans (pink). Black outlined markers indicate CTD sampling stations for each transect type. The inset image of Svalbard provides broader geographic context.

CTNERR working on a new marsh monitoring program

By Shelby Larubina.

22 September 2026. This field season, the Research team at the Connecticut National Estuarine Research Reserve spent over 20 days in the field getting familiar with many of the salt marshes across CT and NY. Working alongside the Maritime Aquarium and UConn’s Department of Ecology and Evolutionary Biology, the CTNERR is collecting data to support a new marsh monitoring program for Long Island Sound. The information collected will be shared with a regional network of scientists and decision makers to improve our understanding of climate impacts and inform restoration on these critical coastal ecosystems.

Reseachers working in a saltmarsh
Shelby Larubina and Josie Mottram; conducting vegetation surveys in the Great Meadows Salt Marsh in Stratford, CT (photo: Emma Coffey)

DMS Prof. Pieter Visscher honored with GSA Career Award

Please join us in congratulating Prof. Pieter Visscher for receiving the Geological Society of America’s 2025 Distinguished Career Award (sponsored by the Geobiology and Geomicrobiology Division). 

Pieter is honored for his decade-long involvement in an NSF-sponsored project that has worked with undergraduate students studying microbial sediments in Puerto Rico. Between 2000 and 2011, Pieter brought 68 of these students to Avery Point for a two-week geomicrobiology short course. None of these first-generation college students had visited the continental US before. His continued encouragement inspired over 60 students in this program to pursue graduate degrees in the US. He taught this course twice in France, once in Argentina, and once in Chile. 

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Prof. Pieter Visscher

Pieter is further commended for his pioneering Astrobiology work, pursuing the fundamental questions: Where are we coming from, where are we going, and what is our future? His tireless curiosity ultimately led to the establishment of NASA’s Astrobiology Institute (NAI) in 1998; the product of a four-decade-long collaboration with scholars, scientists, and engineers from around the country. 

We asked Pieter to name a key paper from the many published in his career - he chose his 2020 study of arsenotrophic microbial mats that allow inferring our past: 

Visscher P.T., K.L. Gallagher, A. Bouton, M.E. Farias, D. Kurth, B.P. Burns, M.R. Walter, M. Sancho-Tomas, P. Philippot, A. Somogyi, K. Medjoubi, E. Vennin, R. Bourillot, M. Contreras, C. Dupraz. 2020. Modern arsenotrophic microbial mats provide an analogue for life in the anoxic Archean.  Nature Communications Earth & Environment 1:24

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Antelope Island at the Great Salt Lake in Utah is one of 50+ sites in more than 20 countries where Visscher has studied fossil and modern analogues of Earth’s oldest known ecosystems.

Citation

 

by Tracy Frank: 

Pieter T. Visscher. Over a distinguished career spanning more than three decades, Dr. Visscher has led advances in our understanding of the complex interactions between microbial communities, biogeochemical cycles, and the formation of sedimentary structures, bridging microbiology and Earth system science. His pioneering studies of microbial mats and stromatolites across a range of settings have illuminated the role of microbes in shaping Earth’s surface environments through time, while his innovative approaches to microbial processes in modern and ancient settings have inspired new directions in research. His atmospheric biosignature studies were instrumental for NASA’s Astrobiology Institute, of which he was a co-founding member. A prolific scholar and respected mentor, Dr. Visscher has authored hundreds of influential publications and trained generations of graduate students who continue to advance the discipline worldwide. His research, collaborations, and leadership have had a transformative impact on geomicrobiology, leaving a legacy that will guide the science for decades to come. 

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A needle microelectrode is being deployed for microscale geochemical measurements in microbial mats.

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Visscher performing 24-h measurements of microbial activities in permanently anoxic ecosystems at Salar La Brava in Chiles Atacama Desert. These ecosystems couple the cycling of carbon to those of arsenic and sulfur, making them the only known modern analogues of the Archean world.

Reply

 

Pieter: Thank you, Tracy, for your kind citation. I am honored to receive this recognition, which has been previously awarded to geochemists, paleontologists, sedimentologists, and geobiologists for whom I have great respect.

As many know, the term geobiology was coined by Lourens G.M. Baas Becking, but not in his monograph “Geobiologie”, published in 1934, but in his inaugural lecture at the University of Leiden on January 28, 1931, entitled “Gaia of leven en aarde”. In this lecture, Baas Becking observed a then recent change in natural and physical scientific research that for the first time were deployed jointly to understand our planet. Furthermore, he expanded his observation that chemistry, biology, and geology did not just apply to the understanding of our planet Earth but provided the foundation for understanding the universe, which he argued was fueled by cyclic events - notably chemical element cycles, but also (micro)biological metabolisms, and physical phenomena, the mutual impact of which was captured in geological time and space. In a way, this laid the groundwork for what, 65 years later, became a motivation for NASA’s Pale Blue Dot II meeting that, in turn, started Astrobiology. Baas Becking viewed geobiology as a Copernican-based science, in other words, perceived not from an anthropocentric, Earth-centric viewpoint, but from a geocentric one. What really matters is that geo(micro)biology is a transdisciplinary science, not just a multidisciplinary one. The answer to “big questions” in this discipline is best solved by first assessing which disciplinary tools are needed, not just by combining disciplinary views that address the question. Despite incredible advances in methodologies in the last four decades, each approach has its limitations. This is critical to remember.

My educational background is based on a combination of organic chemistry and the Delft School of Microbiology – that, in addition to Baas Backing, also included Beijerinck, Kluyver, and van Niel. In addition to having a great mentor, Hans van Gemerden, who combined detailed observations and measurements in the field with meaningful ecophysiological laboratory experiments, I have had the good fortune to meet many scientists who have shaped our discipline as we know it today. The list is quite exhaustive, but I would like to mention a handful of them here briefly, some unsung heroes in geomicrobiology, in chronological order.

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Table-top scanning electron micrograph of a carbonate grain surrounded by and bored into by cyanobacteria.

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As night settles over the Atacama desert, the measurements continue

Wolfgang Krumbein was instrumental during my PhD work on sulfur cycling at the University of Groningen. After a long 24 hours of fieldwork, being in a group that was the first to use microelectrodes in the field during diel cycles, a very tedious process at the time, he would sit me down in his cigar-smoke-filled office and question me about everything I had observed and was planning to do as follow-up. Early in my grad student years, he sent me a box with well over a hundred of his reprints. Using geology and microbiology, his strong belief that the laminae in stromatolites are the same as those in microbial mats may be wrong, but it nevertheless challenged our thinking and steered us in the right direction to better understand the role of microbes on early Earth and throughout geologic time. Spending three weeks with Dick Castenholz and Bev Pierson in Yellowstone was a life-changing event. The vast diversity of environments in a relatively small area was an eye-opener. Likewise, several long discussions, both in the field and during elegant home-cooked meals with Malcolm Walter, have contributed much to advancing my work. Lynn Margulis, who, by the way, together with James Lovelock reintroduced the term Gaia in 1974, 43 years after Baas Becking, Ed Leadbetter, Ron Oremland, Jack Farmer, and Dave DesMarais were all instrumental as post-doc and early career mentors. Generous scientists who gave selfless advice and listened. I learned a lot from them and expanded my scientific and interpersonal horizons. It takes a village….

I would like to thank the people who are keeping our field alive: the leaders of the professional societies, notably the Division of Geobiology and Geomicrobiology of Geological Society of America, the reviewers of our proposals and manuscripts, the program directors at funding agencies, the educators, who sparked the interest in students who then come as graduate assistants or post-docs to our labs, and all those students and colleagues with whom I had many fruitful/stimulating discussions and rewarding collaborations. I am excited about the direction in which our field is moving, and hope that we jointly continue to combine the many subdisciplines that make up geo(micro)biology in a meaningful way to unlock the secrets that our field holds in shaping our planet and the many worlds beyond.

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Visscher at the Galan volcano in Argentina

Avery Point Spotlight: Jeff Godfrey

By: Anne L. Gilewski

Officially, Jeff is an Academic Assistant at UConn's Marine Sciences Department, but if you’ve ever been lucky enough to interact with Jeff, you know he’s far more than that.  Over his 26-year career directing dive operations, Jeff standardized a formal curriculum that includes course work for Open Water Dive and Scientific Diving training and certification.  He also maintained all facilities and equipment, approved dive plans, and has been part of countless research projects that require dive operations. 

Every superhero has an origin story, so we asked Jeff to share his! 

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Jeff Godfrey has had a 26 year long career in diving

Growing up in Utah, Jeff had three dream jobs in his mind: paleontologist, astronaut, or diver. After watching cartoons, Jeff would switch over to Sea Hunt, a 1958 program about the adventures of an ex-Navy frogman, starring a very handsome Lloyd Bridges. After that was The Undersea World of Jacques Cousteau, a series that often served as inspiration for future marine biologists—including Jeff.  

Despite living in a landlocked state, diving found Jeff. During his senior year in high school, when he wasn’t racing motorcycles and boating, Jeff took a diving certification course after school class—a move he says was a good way to get out of chores. Though the impetus may have been to avoid milking the cows, that course set the stage for a lifelong passion.  

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For a long time, Jeff has played a role in the development and field testing of rebreather technology, here at a site in North Carolina more than 15 years ago

Jeff set out to build up a collection of certifications, started snorkeling, free diving, and collecting daphnia and salamanders for local aquarium stores. At 24, he earned his Dive Instructor certification. In 1987, while earning his bachelor’s degree in Applied Biology from Utah State University, Jeff joined the Utah Fish & Wildlife Cooperative Research Unit as a Field Tech and Research Diver. Being a field diver is most decidedly not a desk job. A typical day might be ice diving in the Flaming Gorge reservoir, or monitoring trout habitat in the Green River, maybe even donning 90 extra pounds to face the white water of the Green River!  

After graduation, Jeff accepted a position at the Marine Resources Development Center Underwater Foundation’s MarineLab program in Key Largo, FL. Jeff taught Marine Ecology to students of all ages, conducting lectures on seagrasses, marine algae, mangroves, coral reefs, astronomy, and marine invertebrates—to name a few.  A chance phone call from Avery Point librarian Jan Heckman about an open Dive Safety Office position in a small Connecticut town piqued his interest. In 1999, Jeff and his family moved north, and the rest is history. (Thank you, Jan!) 

Amongst all the diving Jeff had done, we had to know: What was the most memorable? (Spoiler alert! It was hard to choose). 

“Blue water diving in Antarctica. To see that environment—icebergs, Deception, Palmer Station”, Australia, Hong Kong, China, American Samoa, and everywhere in the United States.” Jeff also had the opportunity to dive the USS Monitor and take part in a National Geographic survey in the Bahamas—diving to 430 feet! 

We asked Jeff what it takes to be a DSO at a university. Here’s his advice:  

DSOs facilitate dive operations to be done safely and efficiently. Jeff strongly believes in looking at universities that have a well-developed program. A STEM degree, with coursework in physics, chemistry, and biology, is a critical piece. A research DSO needs to have a solid science background to effectively communicate with investigators—graduate degrees are not uncommon in this field.  Most importantly, spend a lot of time in the water. Diving is a tool; for a diver to be useful, they need to have extensive experience in a variety of conditions. 

Any final thoughts? 

Jeff is grateful to UConn for supporting his endeavors to increase technology for scientific diving here at Avery Point. His hope for the future? UConn continues to push students to take advantage of these advanced technologies in their academic pursuits.  

Thank you, Jeff, for 26 years of service. We wish you the best in your retirement! 

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Jeff (left) doing benthic research with Chris Conroy (right) in Long Island Sound

Seaweed self defense!

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Common periwinkles (Littorina littorea) graze upon the intertidal seaweed Fucus vesiculosus and elicit anti-herbivore defenses (credit: C Matassa)

Did you know that seaweed practices self-defense? A new paper from the Matassa Lab led by recent PhD graduate Sean Ryan on seaweed defense plasticity has been published in Functional Ecology. They investigated how a species of seaweed (Fucus vesiculosus) defends itself from herbivorous snails (Littorina littorea) along its latitudinal range in the coastal northeast USA.

Check out the plain language summary of the article here:

Ryan, S. and Matassa, C.M. (2025) Latitudinal variation in the constitutive and inducible defences of a canopy-forming rocky intertidal seaweed. Function Ecology 39:3718–3731.

New seafloor lander tested and in action

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The ice edge of Hans Glacier in Hornsund fjord, Svalbard

By Elizabeth Weidner.

Over the past year, the Broadband Acoustics Lab, led by DMS Assistant Professor Elizabeth Weidner, designed and built a new kind of seafloor lander to investigate how melting glaciers are transforming the coastal Arctic ocean.

The custom-built instrument houses several advanced sonar systems that use sound to observe processes that are otherwise difficult to capture in remote, ice-covered environments.

The lander was developed, assembled, and tested at the University of Connecticut, in close collaboration with Professor Tom Blanford from the University of New Hampshire. A new DMS graduate student, Cloé Mueller, who joined the lab in the fall, played a key role in system testing and preparation.

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The seafloor lander on board the RV Connecticut for testing in Long Island sound

The lander will be deployed this summer in Svalbard near a marine-terminating glacier, where it will collect long-term acoustic measurements. These data will help the Broadband Acoustics Lab better understand how melting glaciers influence ocean structure, underwater sound propagation, and the rapidly changing Arctic environment.

LizWeidnerBlanfordLander
Members of the broadband acoustics lab testing the lander deployment with the Jere A Chase engineering team at the University of New Hampshire (left to right: Elizabeth Weidner, Cloé Mueller, Thomas Blanford)

DMS students help mapping sediments and fauna in Long Island Sound

Carlee Dunn and Riley Pena, DMS graduate students in the Matassa Lab, worked alongside researchers from the University of Connecticut, University of New Haven, and US Geological Survey aboard the R/V Connecticut to map benthic habitats in western Long Island Sound. The cruise used USGS’s Seabed Observation and Sampling System (SEABOSS) to capture video and sample seafloor sediments and benthic organisms, such as brittle stars.

The team’s research is part of the Long Island Sound Habitat Mapping Initiative, which aims to characterize the regions seafloor habitats. You can see more of the action on the teams facebook page!

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Riley Pena (l.) and Carlee Dunn (r.) with the SEABOSS on board the R/V Connecticut

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A brittlestar, related to see urchins and sea stars, is retrieved from the SEABOSS samples

DMS researchers test novel underwater “presenter” helmet

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Prof. emer. Peter Auster during the test dive of the new presenter helmet

21 May 2025
Research Professor Emeritus Peter Auster led a development project to demonstrate the utility of a "presenter helmet" and integrated oxygen rebreather to engage audiences with video recorded directly from environments of interest. The novel helmet allows an expressive human face and voice rich in excitement, in contrast to standard helmets and full-face masks.

The field test was conducted from the RV Weicker in a shallow seagrass meadow off Avery Point. The project was funded by CT SeaGrant with vessel support from the CT National Estuarine Research Reserve. Mike Lombardi from Lombardi Undersea LLC designed and built the helmet, rebreather, and submersible video "studio" complete with voice from the helmet. Associate Professor Jason Krumholz from the CT Reserve also dove the helmet and collected multiple video segments for posting over the web. The potential for “live dives” with a host on the seafloor is a possibility in the future.

Celebrating Student Research at the 15th Biennial Feng Colloquium

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Most of the participants of the 15th biennial Feng Colloquium at DMS on 15 May 2025

By Samantha Rush.

On May 15, 2025, the Department of Marine Sciences hosted the 15th Biennial Feng Graduate Research Colloquium. Named in honor of the first department head, Dr. Sung Y. Feng, the colloquium serves as a professional development event for our departments graduate students, who hone their skills in abstract writing, posters presentations and research talks. This year’s program featured 18 talks and 22 posters showcasing the breadth of multidisciplinary work across the department.

Started by Dr. Hans Dam in 1996, the 2025 Feng Steering Committee included Dr. Julie Granger, Emily Watling, Yifan Zhu, and Anne Gilewski. This year’s event also featured artwork by Matthew Leason and was made possible with the support of DMS staff, particularly Deb Schuler and Todd Fake. The event continues to be a valuable platform for students to hone their scientific communication skills, receive feedback, and share their work across the department.

Check out the talks, posters, and their abstracts here!

Check out a few more impressions from the day below!

Feng Colloquium 2025
Artwork by Matthew Leason

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Yifan (r.)

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Jessica (l.) & Xavier (r.)

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Eva (r.)

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DMS mingling at the Poster session

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Madison

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Dave (l.), Paban (m.) & Xavier (r.)

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Sunnidae (l.) & Pax (r.)

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Penny (l.), Evan (m.) & Hans (r.)

FengS-02
Vicki You

FengS-03
Matthew (l.) & Sarah (r.)

FengS-06
Anne (l.)

FengS-13
Sunnidae

Graduate Students Bring Ocean Science to Life at Sip ‘n Science Event

By Samantha Rush.

Last Friday, DMS graduate students hosted the annual Sip ‘n Science event at Beer’d Brewing Co. in Stonington, featuring interactive science demonstrations for the local community. Despite a torrential downpour outside, the event was well attended and highlighted meaningful engagement between students, faculty, and the public. Students designed demonstrations of oceanographic principles or their own research, showcasing the breadth of work at the Marine Sciences department while also gaining valuable experience in communicating complex scientific concepts to a general audience.

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Erin Leathrum (l.) and Sarah McCart (r.) found a way to visualize microfossils.

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Carley Dunn (l.) and Halle Berger (r.) having fun showing off macrobenthic organisms.

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Hannah Roby (r.) and her giant cardboard black sea bass.

This year’s demonstrations covered a wide range of topics, including microfossils, mercury, marshes, ocean waves, isotopes, ocean acidification, the Coriolis force, sea ice brine, Black Sea Bass gut contents, planktonic species, and coastal snails and crabs. Students were nothing short of creative - designing wave tank races, ranking games for mercury-impacted species, isotope explanations using the Hungry Hungry Hippos game, visual displays of acidification effects on seashells, rotating table experiments with dye to show ocean forces, larger than life-sized sea bass cutouts, and salty ice cubes to simulate polar sea ice processes.

Well done, everyone! The department is truly proud of its graduate students!

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Genius! Hungry hungry Hippos to visualize isotopes or just to have fun ...

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You never know when passion starts. Outreach plants seeds.

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Julie Granger (l.) and Catherine Mattassa (r.) - Sip 'n Science!

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Emma Siegfried (l.) dissolving shells - ocean acidification illustrated.

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Catherine Crowley (l.), Alex Frenzel (m.), and Peter Ruffino (r.).

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Bernard Akawaase explains the wave tank

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A highlight was Paban Bhuyan's and Bernard Akaawase's (not shown) rubber ducky wave tank.