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Departmental Achievements, Spring 2021

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There have been many achievements in our department in the past months! Here are highlights of recent awards, grants, and publications in the Department of Marine Sciences from October 2020 through April 2021.

Awards Description
Prof. Senjie Lin Elected as an AAAS (American Association for the Advancement of Science) Fellow and joined the 2020 ASLO (Association for the Sciences of Limnology and Oceanography) Fellows. These honors recognize his work in dinoflagellate biology and biological oceanography as a whole.
Prof. Ann Bucklin Received the 2020 UConn Faculty Excellence in Research and Creativity Award in the Sciences.
Allison Staniec (graduate student, Prof. Penny Vlahos) Chosen in the National Science Foundation’s (NSF) Dissertations in Chemical Oceanography (DISCO) Fellowship.
Hannah Collins (graduate student, Prof. Evan Ward) Awarded a grant from the Lerner-Gray Memorial Fund for Marine Research.
Tyler Griffin (graduate student, Prof. Evan Ward) Awarded the Melbourne R. Carriker Award from The National Shellfisheries Association.
Melissa Sanchez (undergraduate student) Awarded Sea Grant Summer 2021 Undergraduate Research Fellowship. She will examine the influence of selenium on the accumulation of methylmercury in phytoplankton with Prof. Robert Mason.

 

Grants Description
Prof. Samantha Siedlecki and Prof. Catherine Matassa NOAA OAP: Assessing vulnerability of the Atlantic Sea Scallop social- ecological system in the northeast waters of the US (2020-2023), $1,034,822. PIs Siedlecki, Meseck, Colburn, Matassa, Curchitser, Bethoney. This grant is for a collaboration between UConn, NOAA’s Northeast Fisheries Science Center (NEFSC), Commercial Fisheries Research Foundation (CFRF), and Rutgers University to study the impact of ocean acidification on Atlantic Sea Scallops in the US northeast and the development of management tools.
Prof. Samantha Siedlecki NOAA MAPP: The predictability of oxygen and its metabolic consequences for fisheries on decadal time scales (2020-2013), $439,315. PIs Siedlecki, Long, Petrik.

NOAA MAPP: Modeling Climate Impacts on Predictability of Fisheries and Other LMRs (2020-2023), $511,452. PIs Long, Siedlecki, Petrik.

NOAA MAPP: Towards the prediction of fisheries on seasonal to multi-annual time scales (2020-2023), $510,000. PIs Petrik, Long, Siedlecki.

NOAA MAPP: Building capacity for predictability of climate impacts on living marine resources in US coastal systems using the NOAA MOM6 ocean model. (2021-2024), $1,513,782. PIs Curchitser, Alexander, Resplendy, Siedlecki, Stock.
Prof. Heidi Dierssen NASA Ocean Biology and Biogeochemistry: Advancing Remote Sensing of Microplastics on the Surface Ocean (2021-2024), $401,914. PIs. Dierssen, Chowdhary, Ottaviani, Ibrahim, Knobelspiesse

NASA Ocean Biology and Biogeochemistry: Quantifying linkages between sea ice, phytoplankton community composition, and air-sea carbon fluxes west of Antarctic Penninsula through field, airborne and satellite (2020-2023), $1,095,330. PIs. Dierssen, Schofield, Stammerjohn, Munro.
Prof. Penny Vlahos EPA/NYSG/CTSG: Alkalinity in Long Island Sound Embayments (ALISE) (03/01/2021-02/28/2023), $131,088. We are investigating the range of alkalinity and carbonate saturation in several LIS embayments to identify areas where conditions may be of concern for aquatic species.

NIH-RO1: Chronic Kidney Disease of Unknown Etiology: Applying a Multidisciplinary Approach to Investigate the World’s Most Common Tubulointerstitial Kidney Disease (09/01/2021-08/31/2026), $528,717. This project is a continuation of our original R21 grant to conduct water quality testing in endemic and non-endemic regions to identify possible causative elements.

NSF: Carbonate system dynamics and biogeochemistry in a changing Arctic (05/01/2021- 04/30/2023), $272,619. We will be performing a suite of biogeochemical measurements in the marginal ice zone to understand the unique chemistry of this receding region.
Prof. Evan Ward and Prof. Sandra Shumway Establishing robust bioindicators of microplastics in Long Island Sound: Implications for reliable estimates of concentration, distribution, and impacts. Awarded by the Long Island Sound Study Research Grant Program, a cooperative program of the EPA Long Island Sound Office, Connecticut Sea Grant (CTSG), and New York Sea Grant (NYSG).

 

Publications Description
Prof. Peter Auster Prof. Auster presents a publication describing a rarely observed feeding frenzy of deep-sea sharks feeding on an Atlantic swordfish recently settled to the seafloor, including predation on a small shark by a wreckfish. (Auster, P.J., K. Cantwell, R.D. Grubbs, S. Hoy. (2020).  Observations of deep-sea sharks and associated species at a large food fall on the continental margin off South Carolina, USA (NW Atlantic).  J. Ocean Sci. Found., 35 (2020), pp. 48-53.)

Prof. Auster and Marine Science Major Lissa Giacalone pioneered a new approach for using 360-degree camera technology for analyzing the interactions of single and mixed species groups of predators and their prey in Gray’s Reef National Marine Sanctuary. (Auster, P.J. and Giacalone, L. (2021). Virtual Reality Camera Technology Facilitates Sampling of Interactions Between Reef Piscivores and Prey. Marine Technology Society Journal 55(2):54-63)
Prof. Zofia Baumann Prof. Baumann and colleagues present research explaining how the kidneys and liver of water birds detoxify methylmercury. (Poulin, B. A., Janssen, S. E., Rosera, T. J., Krabbenhoft, D. P., Eagles-Smith, C. A., Ackerman, J. T., … & Manceau, A. (2021). Isotope Fractionation from In Vivo Methylmercury Detoxification in Waterbirds. ACS Earth and Space Chemistry.)
Prof. Penny Vlahos Prof. Vlahos contributed to the United Nations Second World Ocean Assessment (WOA II), the newest outcome of the only integrated assessment of the world’s ocean at the global level covering all three pillars of sustainable development. (https://www.un.org/regularprocess/)
Prof. Michael Whitney and Prof. Penny Vlahos Profs. Vlahos and Whitney show that mitigation efforts have reduced hypoxia in Long Island Sound, but also that warming waters are working against these trends. (Whitney, M. M., & Vlahos, P. (2021). Reducing Hypoxia in an Urban Estuary Despite Climate Warming. Environmental Science & Technology, 55(2), 941-951.)
Prof. Sandra Shumway Prof. Shumway was part of an international team of researchers reviewing the developments in global aquaculture over the past two decades highlighting its integration in the global food system. (Naylor, R. L., Hardy, R. W., Buschmann, A. H., Bush, S. R., Cao, L., Klinger, D. H., … & Troell, M. (2021). A 20-year retrospective review of global aquaculture. Nature, 591(7851), 551-563.)
Prof. Heidi Dierssen NASA has a proposed mission called the Surface Biology and Geology (SBG) mission as recommended by the 2018 Decadal Survey. Dierssen recently participated in a large collaborative effort to review existing hyperspectral and thermal algorithms relevant to the SBG mission across the following categories: snow/ice, aquatic environments, geology, and terrestrial vegetation, and summarize the community-state-of-practice in each category. (Cawse-Nicholson, K. et al.  (2021). NASA’s surface biology and geology designated observable: A perspective on surface imaging algorithms. Remote Sensing of the Environment. 257: 112349.)

Red and green algae growing on snow in the Antarctic Peninsula causes significant extra snowmelt that is on par with melt from dust on snow in the Rocky Mountains, according to a first-of-its-kind scientific research study that Dierssen worked on. (Khan, A. L., H. Dierssen, T. Scambos, J. Höfer, and R. R. Cordero. (2021). Spectral Characterization, Radiative Forcing, and Pigment Content of Coastal Antarctic Snow Algae: Approaches to Spectrally Discriminate Red and Green Communities and Their Impact on Snowmelt. The Cryosphere. 15, 133-148.)
Prof. Julie Granger From seasonal surveys, we show that nutrients inshore are persistently higher than in source waters offshore in the Southern Benguela Upwelling System (eastern Arctic Ocean), due to benthic-pelagic coupling of production and regeneration on the broad and shallow shelf. The incidence of “nutrient trapping” inshore explains the high productivity of system and explains hypoxic events. (Flynn, R. F., Granger, J., Veitch, J. A., Siedlecki, S., Burger, J. M., Pillay, K., & Fawcett, S. E. (2020). On‐shelf nutrient trapping enhances the fertility of the southern Benguela upwelling system. Journal of Geophysical Research: Oceans, 125(6).)
Prof. Robert Mason Prof. Mason and past graduate student Emily Seelen investigated differences in mercury cycling in contaminated versus uncontaminated estuaries in the US northeast. (Seelen, E. A., Chen, C. Y., Balcom, P. H., Buckman, K. L., Taylor, V. F., & Mason, R. P. (2021). Historic contamination alters mercury sources and cycling in temperate estuaries relative to uncontaminated sites. Water Research.)

Prof. Mason and colleagues examined how factors such as mercury concentration in water and sediment, and the watershed land use, influenced the concentrations of mercury in mummichogs and silversides in estuaries from the Chesapeake Bay to northern Maine. (Buckman, K.B., Mason, R.P., Seelen, E.A., Buckman, K.B., Taylor, V.F., Balcom, P.H., Chipman, J., Chen, C.Y. (2020). Patterns in forage fish mercury concentrations across Northeast US estuaries. Environ. Res. 194, Art. # 110629.)
Prof. Ann Bucklin This review is a collaborative effort of the Scientific Committee for Ocean Research (SCOR) Working Group WG157: MetaZooGene.  The MetaZooGene Barcode Atlas and Database (MZGdb) includes >150,000 mitochondrial cytochrome oxidase I (COI) sequences for ~5,600 described species of marine zooplankton. The MZGdb is a reference database for identification of species from DNA barcoding and metabarcoding of pelagic biodiversity, with advanced search functions by ocean region and taxonomic group. (Bucklin et al. (2021) Toward a global reference database of COI barcodes for marine zooplankton.  Marine Biology.)
Gihong Park (postdoc, Prof. Hans Dam) Prof. Dam and Park present a novel framework to incorporate the cost of defense in toxin-producing prey/predator relationship models. This paper was selected in Faculty Opinions as one of special significance in its field, considered as highly important emerging research. (Park, G., & Dam, H. G. (2021). Cell-growth gene expression reveals a direct fitness cost of grazer-induced toxin production in red tide dinoflagellate prey. Proceedings of the Royal Society B, 288(1944).)
Kelly McGarry (graduate student, Prof. Samantha Siedlecki) McGarry and colleagues developed equations to estimate highly variable carbonate system properties in northeast US shelf waters from other variables – temperature, salinity, oxygen, and nitrate – that are affected by the same processes that drive carbonate system variability but are measured more frequently with better spatial coverage. (McGarry, K., Siedlecki, S. A., Salisbury, J., & Alin, S. R. (2021). Multiple linear regression models for reconstructing and exploring processes controlling the carbonate system of the northeast US from basic hydrographic data. Journal of Geophysical Research: Oceans, 126(2).)
Veronica Rollinson (research assistant, Prof. Julie Granger) Rollinson and colleagues measured nutrients and the naturally occurring nitrogen (N) and oxygen (O) stable isotope ratios of nitrate discharged from the Pawcatuck River over an annual cycle and uncovered a seasonality to loading and sources of N from the watershed. Seasonality in the nitrate isotope ratios also informed on N cycling. (Veronica R. Rollinson, Julie Granger, Sydney C. Clark, Mackenzie L. Blanusa, Claudia P. Koerting, Jamie M. P. Vaudrey, Lija A. Treibergs, Holly C. Westbrook, Catherine M. Matassa, Meredith K. Hastings, and Craig R. Tobias (2021). Seasonality of nitrogen sources, cycling and loading in a New England river discerned from nitrate isotope ratios. Biogeosciences discussion.)

Marine Animals Could Be Used to Clean Up Nature’s Big Pollutant: Microplastics

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Over the next four years, faculty from the School of Engineering and College of Liberal Arts and Sciences, including marine sciences professors Evan Ward and George McManus, will use a $2 million grant from the National Science Foundation’s Emerging Frontiers in Research and Innovation (EFRI) program to study the use of mussels (bivalves), combined with microplastic-degrading bacteria, to remove microplastics from the discharge of wastewater treatment plants. For more information about this project see https://today.uconn.edu/2021/03/how-marine-animals-could-be-used-to-clean-up-natures-big-pollutant-microplastics/.

Red Tide Prey Defense is a Costly Business

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Postdoctoral investigator Gihong Park and Professor Hans Dam published a study in the Proceedings of the Royal Society B that demonstrates a fitness cost of defense in a red tide dinoflagellate. Organisms must defend themselves against their consumers. It has long been hypothesized that defenses such as toxin production may come at a cost in the form of reduced growth. Yet, demonstrating such costs of defense is challenging. Park and Dam’s study presents a novel approach using a growth-related gene to show that when a red tide dinoflagellate (phytoplankton) is exposed to a copepod grazer, it increases toxin production but decreases its growth gene marker, indicating a fitness cost of toxin production. While costly, the defense is adaptive because it lowers the consumer ingestion rate and it allows the dinoflagellate to persist. The findings have important implications for understanding the factors that control the rise and fall of red tide blooms. Such blooms plague coastal regions wreaking havoc on local fisheries economies and threatening public health.

Link to the paper: https://royalsocietypublishing.org/doi/10.1098/rspb.2020.2480

Viruses, the “good”, not the bad or ugly

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The viruses may be the missing link in the evaluation of life. Formation of Earth’s oldest ecosystems, stromatolites, requires a deeper understanding of several virus-mediated mechanisms that change the cyanobacterial behavior through geologic time, including the “invention” of oxygen-producing photosynthesis. Cyanobacteria also precipitate and cement the carbonate minerals, a stromatolite is preserved in the fossil record, some for as long as 3,500 million years. Without the interception of viruses, this may not have happened and further evolution of life and biogeochemistry that resulted in the Cambrian explosion would have been different. A planet without humans….?

https://today.uconn.edu/2021/02/lifes-surprising-debt-to-viruses/

Mechanisms proposed for virus-cyanobacteria interaction. Image: Richard White III

Marine Sciences graduate student Alec Shub working with Governor’s Council on Climate Change

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For the past several months Alec Shub has been working with Connecticut’s Department of Energy and Environmental Protection (DEEP), coordinating reports for the Governor’s Council on Climate Change (GC3). The GC3 was established by executive order, in an effort to mitigate greenhouse gas emissions and address strategies for adaptation and resilience to the impacts of climate change throughout the state of Connecticut. One of the Council’s goals is to help the state meet its target of an 80% reduction in greenhouse gas emissions (below 2001 levels) by 2050. This effort has garnered collaboration between an eclectic team of 23 council members and 230 working group members, including experts from a wide range of scientific disciplines, state agencies, local governments, non-profits, and businesses.  As a result of his work, Alec has learned how different fields are able to come together and collaborate on a central issue.   As a graduate student, Alec volunteered with the Connecticut Institute for Resilience and Climate Adaptation (CIRCA), which was an important stepping stone to the GC3 position.   He also believes the GC3 experience will be invaluable preparation for his upcoming Knauss Fellowship with the National Oceanic and Atmospheric Administration’s (NOAA) Climate Program Office.

If you are interested in learning more about the GC3 or reading any of the working group reports, you can visit the page on the DEEP website:

https://portal.ct.gov/DEEP/Climate-Change/GC3/Governors-Council-on-Climate-Change

Christening the Automated Larval Fish Rearing System (ALFiRiS) at the DMS Rankin Lab

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Rankin Lab, December 2020. After using and tinkering with our experimental system at the Rankin Seawater Lab of the University of Connecticut’s Department of Marine Sciences for over 5 years, it’s finally time to give the baby a name – ALFiRiS.

Over the past years, the Evolutionary Fish Ecology Lab of Prof. Baumann has built an Automated Larval Fish Rearing System (ALFiRiS) to conduct factorial experiments on the climate sensitivity of fishes. It consists of a 3 x 3 array of recirculating units (600L/150gal) that have independent computer-control over their temperature, oxygen, and pH conditions. We use a self-developed LabView (National Instruments) platform to sequentially monitor tank conditions via industrial-grade oxygen and pH sensors (Hach) and then control gas solenoids (air, N2, CO2) to maintain and modulate environmental conditions. The system can apply static as well as fluctuating conditions on diel and tidal scales. Computerized temperature control further allows simulating heatwaves and other non-static thermal regimes. We’ve only begun to explore all of ALFiRiS’ capabilities.

To learn more, go to https://befel.marinesciences.uconn.edu/alfiris/

Dierssen Lab Earns Recognition from NASA

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Dr. Heidi Dierssen, Professor in Marine Sciences, and her postdoc Brandon Russell were among the individuals recognized by NASA during its 2020 Honor Awards event that was held on December 1. They were part of the Coral Reef Airborne Laboratory Mission Team that collected and  delivered unprecedented data about reef environments.

Brandon Russell

Departmental Achievements, Fall 2020

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There have been many achievements in our department in the past months! Here are highlights of recent awards, grants, and publications in the Department of Marine Sciences from April 2020 through October 2020.

Awards Description
Prof. James O’Donnell O’Donnell was appointed to the Governor’s Council on climate change, and now serves as the co-Chair of the Science Subcommittee. Co-authored two draft interim reports.
Prof. Pieter Visscher Visscher was appointed to the executive committee of the Australian Centre for Astrobiology.
Prof. Cesar Rocha Rocha received the Editors’ Citation for Excellence in Refereeing for Geophysical Research Letters from the American Geophysical Union (AGU).
Kayla Mladinich (grad student, Prof. J. E. Ward) The Ruth D. Turner Foundation awarded Kayla Mladinich the Ruth D. Turner Fellowship for her project titled “Evaluating bioindicator Species of Microplastics in the Marine Environment: A Comparison of Bivalves, Gastropods, and Tunicates.”
Halle Berger (grad student, Prof. Catherine Matassa and Prof. Samantha Siedlecki) Berger was placed with the NOAA OAR Ocean Acidification Program and NOAA NOS National Centers for Coastal Ocean Science Competitive Research Program as their coastal stressors (ocean acidification and harmful algae blooms) program coordinator as part of the 2021 Knauss Marine Policy Fellowship Program.

 

Grants Description
Prof. Heidi Dierssen Dr. Dierssen was recently awarded a large NASA grant for an interdisciplinary project with colleagues at Rutgers University and University of Colorado exploring the uptake of carbon dioxide in a rapidly changing oceanic region near the West Antarctic Peninsula.  Specifically, she will lead the team evaluating linkages between sea ice, mixed layer depth, optical properties, carbon export and other biogeochemical and physical parameters on phytoplankton biomass, community composition, and productivity.
Prof. Hans G. Dam Linking eco-evolutionary dynamics of thermal adaptation and grazing in copepods from highly seasonal environments. National Science Foundation, $531,434. The grant tests how warming oceans changes the feeding habits of the most abundant animals on Earth, copepods.

 

Publications Description
Prof. Pieter Visscher Dr. Visscher presents two new publications on arsenic cycling in the preoxygen world, based on research in 2.72 billion year old rocks and modern microbial mats in the Atacama Desert (Chile). This groundbreaking work has been featured in multiple online articles, radio, television, and newspapers. (Modern arsenotrophic microbial mats provide an analogue for life in the anoxic Archean) (Evidence for arsenic metabolism and cycling by microorganisms 2.72 billion years ago)
Prof. James O’Donnell Dr. O’Donnell and colleagues worked on a collaborative project to model storm surge and wave heights for flood risk assessments. This project yielded an interactive map on the CIRCA website: The Connecticut Costal Towns Storm Annual Exceedance Probability/Return Interval Viewer. (Estimating the Annual Exceedance Probability of Water Levels and Wave Heights from High Resolution Coupled Wave-Circulation Models in Long Island Sound)
Prof. Robert Mason, Assistant Prof. Zofia Baumann, and Gunnar Hansen (grad student) Sediment, water, forage fish and invertebrates were collected and analyzed for mercury forms from sites in the Still River, CT that had been impacted by mercury pollution from hat making in Danbury in the late 19th/early 20th century as well as from unimpacted sites to examine the legacy of this contamination. (Evaluating the impacts on local fish from the eastern United States)
Prof. Heidi Dierssen Dr. Dierssen published a new remote sensing method with colleagues from the NASA CORAL project in Remote Sensing of the Environment for classifying shallow seagrass and benthic algae habitats and simultaneously characterizing the water column properties including phytoplankton concentrations. (Benthic classification and IOP retrievals in shallow water environments using MERIS imagery)
Prof. Hans G. Dam and Postdoc Matt Sasaki Recent publication showing that genetic adaptation is important to predict how animals cope with the ongoing ocean warming. (Genetic differentiation underlies seasonal variation in thermal tolerance, body size, and phenotypic plasticity in a short-lived copepod)
Prof. Hannes Baumann Recent publication showing that oxygen consumption in fish embryos, but not larvae, is affected by acidified water conditions. (Synergistic metabolic responses of embryos, but not larvae, of a coastal forage fish to acidification and hypoxia)

Recent publication showing that fish grow up smaller under acidified water conditions, but these effects do not differ between males and females. (Are long-term growth responses to elevated pCO2 sex-specific in fish?)
Prof. Cesar Rocha Working on the problem of horizontal convection, Rocha and collaborators discovered a mathematical identity that relates the horizontal buoyancy flux (or heat flux) to the molecular dissipation of buoyancy (or temperature) variance. This new identify justifies the definition of a horizontal-convective Nusselt number in analogy to the Nusselt number of the more widely studied Rayleigh-Bénard convection. (The Nusselt numbers of horizontal convection)
Yipeng He (grad student, Prof. Robert Mason) During a research cruise from Alaska to Tahiti, samples were collected for determining the concentrations and forms of mercury in the atmosphere. Two methods were compared in the paper as there has been controversy over the accuracy of one of the methods. (Comparison of reactive gaseous mercury measured by KCl-coated denuders and cation exchange membranes during the Pacific GEOTRACES GP15 expedition)
Tyler Griffin (grad student, Prof. J. E. Ward) Recent publication comparing and discouraging the use of fecal sampling as a substitute of gut samplings for the blue mussel. (Direct Comparison of Fecal and Gut Microbiota in the Blue Mussel (Mytilus edulis) Discourages Fecal Sampling as a Proxy for Resident Gut Community)
Prof. Senjie Lin Visiting scholars in Lin Lab Tangcheng Li and Hongfei Li recently published papers with Professor Senjie Lin in Science in the Total Environment about how a harmful algal bloom dinoflagellate and a coral endosymbiont dinoflagellate cope with nitrogen-nutrient deficiency and about tolerance of ammonium toxicity. (Transcriptome profiling reveals versatile dissolved organic nitrogen utilization, mixotrophy, and N conservation in the dinoflagellate Prorocentrum shikokuense under N deficiency)

Research Continues Safely Amid COVID-19

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Mesocosm
Wesley Huffman inspecting his salt marsh mesocosm for an experiment.

COVID-19 has drastically changed all aspects of our lives, including how we teach, do research, and stay connected at UConn. The Department of Marine Sciences is adapting to a new normal, and this Fall Semester has been unlike any other.

Classes are mostly online, however, some courses have continued in-person. In these situations, students are of course practicing social distancing and wearing their masks. Classes which feature research cruises and scuba diving were thankfully able to carry out these activities safely. Graduate student Wes Huffman comments on his positive experience with his online classes. “I initially thought an online discussion-based course would be challenging, with either no one discussing or people talking over each other. I have also previously found online lectures to be more challenging to pay attention to. However, video-based online discussion has worked exceptionally well and has been on par with similarly styled in-person courses.”

Research is affected but still continuing safely. Everyone working indoors is required to wear masks, social distance, and check in and out of each lab space (for contact tracing). Most professors and students are working from home often or even entirely, only coming to campus when it is necessary. This has resulted in many adaptations to ongoing research. Wes shares, “One of my projects that has been ongoing during COVID is a series of mesocosm experiments… Remote monitoring and control of this experimental system have been critical in allowing me to continue working from home when possible while streamlining in-person sampling. This not only mitigates potential COVID exposure but has improved the quality of data gathered by being able to fine-tune parameters more frequently than otherwise feasible while in the lab.”

Rosette Preparation
Graduate students prepping the sampling rosette as part of the Oceanographic Expedition course.

In such a unique situation, new opportunities have also been possible. Molly James, a graduate student, shares her experiences. “A great opportunity that I wouldn’t have been able to do under normal circumstances is attend meetings of the Governor’s Council on Climate Change (GC3). My advisor suggested I participate in the virtual meetings for the GC3’s Science and Technology Working Group. As a result, I produced information sheets for the public detailing climate change impacts and projections in Connecticut.”

This year, mostly everything has been online. Seminars and brown bags are both continuing regularly on WebEx. However, these weekly events were set times that many of us from the department would step away from our individual work and get to see each other. The online meetings, both professional and social, bring feelings of isolation, as expressed by many people.

On the bright side, since we’re all staying at home more than usual, this seems to have caused a widespread interest in pursuing new hobbies. Molly shares, “Some silly results of quarantining are rearranging my bedroom and living room (more than once) after becoming mildly addicted to DIY and home decor YouTube channels; baking many loaves of bread; attempting to become a jogger/runner; doing a language exchange with a friend in Seoul; and many hours on friend group video chats.”

 

A student using a salinometer outside during Prof. Pieter Visscher’s in-person geomicrobiology class. (Bri Diaz/UConn Photo)
Deploying Sensors
Temperature and Relative humidity sensors deployments to the City of New Haven. Molly James (left) and Kay Howard-Strobel (right) are attaching them.

Building the Groundwork for Remote Sensing and Tracking of Plastics in the Ocean

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Dierssen and Garaba
Dierssen and Garaba using a spectrometer to measure the spectral properties of washed-ashore plastics at the Mystic Aquarium.

We’ve all heard stories about the garbage patches that are kilometers wide floating out in the ocean. While the garbage islands that many of us imagine are much closer to fiction, there is definitely a lot of plastic in the ocean, and most of it is in the form of microplastics (<5mm). This makes it difficult to identify and track the plastics that are floating around.

Satellites are able to find things like plankton blooms in the ocean by their spectral information (such as color). However, when it comes to plastics, they all have different colors and compositions and can be very small in size. This makes it tricky to distinguish plastic floating on the ocean surface.

In a recent publication, Professor Heidi Dierssen and a former postdoctoral researcher from her lab, Dr. Shungu Garaba now at the University of Oldenburg in Germany, built a database of the spectral information of many different types of plastics. They measured spectral reflectance, which represents the “color” of the objects, in the ultraviolet (UV), visible, and infrared (IR) parts of the spectrum. As explained in the publication, “The spectral reflectance of an optically active object (e.g. plastic, coral, seawater, algae, sediment) has a characteristic shape that explains how it can reflect or absorb light. The spectral shape is a combination of peak (reflection or fluorescence) features and trough (absorption) features that are distinctive optical properties of the objects.”

spectral reflectance measurement of marine microplastic particlesThe figure above is an example of a spectral reflectance measurement of marine microplastic particles, showing dips (troughs) of the curve highlighted with gray lines. These dips, called absorption features, are unique to the object and can help identify the type of plastic. Dashed lines represent standard deviation.

Microplastics
Assorted marine-harvested microplastics.

Dr. Dierssen and Dr. Garaba sampled many different types of plastics that are representative of what would actually be found floating in the ocean. “Many research studies on marine plastics purchase new plastic bottles and other debris for their studies. This does not represent the actual objects found floating on the ocean surface and their environmental state,” Dierssen explains. The types of plastics that were sampled included microplastics (0.3- 5 mm), macroplastics (>5mm), and new plastic polymer pellets (for comparison). Microplastics were collected from the Atlantic and Pacific Ocean using surface-sampling nets. Macroplastics were sampled at the Mystic Aquarium, as part of a traveling exhibit raising awareness about plastic pollution, titled “Washed Ashore: Art to Save the Sea.” These plastics (buoys, containers, ropes, toys, nets, etc.) were collected from beach clean-ups on the West Coast. Dierssen describes that “their colors and material had been weathered by the sun and exposed to ocean turbulence. This provided a much closer library of real plastic objects that would be observed floating at sea than if we purchased new [plastics].”

The large plastics washed ashore are easily identifiable, but much less is known about the composition of the small microplastic particles found floating at the sea surface. To address this, Dierssen and Garaba also measured reflectance from new plastic pellets of 11 different polymer types.  Absorption features of microplastics were compared to the plastic pellets to determine the closest matching spectral properties.  The microplastics were most similar to low-density polyethylene and polypropylene often used in bottles and packaging material.

The measurements of the different types of plastics from this study are available in an open-access database as a reference for others.  This data will help with remotely sensing and tracking plastics in the ocean, and eventually be used to identify the types of plastics floating around from satellites! As Garaba states, “Our contribution to the monitoring of plastics is the groundwork of understanding the key properties of plastics that can be used to develop algorithms/models/statistical approaches to derive essential descriptors about the plastics from remote sensing tools since these plastics have an optical signature or a unique light signal.”

Dierssen and Garaba recently submitted a NASA proposal to continue their collaboration to develop ways to remotely sense microplastic particles across the global ocean. Look forward to hearing more from them in the future!

 

Citation:
Garaba, S. P., & Dierssen, H. M. (2020). Hyperspectral ultraviolet to shortwave infrared characteristics of marine-harvested, washed-ashore and virgin plastics. Earth System Science Data. DOI:10.5194/essd-12-77-2020