ENVS Summer Research – Kevin and Joe

Kevin in the CNS lab

This summer, we researched a mineral known as pyrrhotite, an iron-sulfide prone to oxidation and subsequent deterioration. It has been implicated in the cracking of foundations in homes across northeastern Connecticut. Such damage can require renovations running into the thousands and even hundreds of thousands of dollars. Therefore, pyrrhotite testing of concrete has been a major subject of focus in the Environmental Science Program, with the main objectives being to develop a comprehensive method for measuring pyrrhotite contamination and estimating probable-effect-concentrations.

Current Trinity sampling methods utilize a combination of X-Ray Diffraction (XRD), Carbon Nitrogen and Sulfur analysis (CNS), and magnetic susceptibility to determine mineralogy and sulfur concentration. In short, sulfur concentration is an indicator of pyrrhotite concentration, but pyrrhotite is not the only sulfur-bearing mineral present in concrete samples. Thus, the objective this summer was to determine the extent to which other sulfur-bearing minerals contribute to overall sulfur concentration. The process involved calibration/adjustment of the CNS analysis method in conjunction with XRD analysis. Our  overall goal is to provide a more comprehensive quantification of pyrrhotite in concrete. We also worked on understanding the relationship between pyrrhotite and its oxidative products. Such knowledge is key to achieving better risk assessment as well as establishing a time scale for concrete deterioration.

Joe breaking apart a concrete core sample.

An X-ray Diffraction (XRD) scan comparing a pure pyrrhotite sample to concrete.



ENVS Research on Concrete Foundations Makes Local News

It all started about a year ago when Jon and Christoph began analyzing crumbling concrete foundations from northeastern Connecticut. The presence of pyrrhotite, a magnetic (you might see where this is going) iron sulfide, in aggregate used for concrete foundation lead to the premature decay of homes as the pyrrhotite decays into a variety of secondary minerals.

In collaboration with the Connecticut Coalition against Crumbling Basements (CCACB) Jon and I started analyzing concrete samples and found that we could detect and quantify pyrrhotite through a combination of magnetic and chemical analyses. In February we submitted a manuscript to Cement and Concrete Research describing our method, talked to homeowners, realtors and engineers, and for the past few months we have been analyzing people’s homes.Trinity’s Alumni Magazine was the first to spread the word. A very famous wall made it on the title page (still bummed that they chose the wall over a heroic portrait of Jon and myself :-), and we got a few pages in he bowels of the issue. The Manchester Journal Inquirer came next, giving us a nice shout-out (yep, you have to read all the way to the end – we’re not that famous), and the Hartford Courant followed suit a few days later. They actually wrote a story about us and, if you are really observant you might see the same wall again in the multi-media part.

In the mean time we got some video practice with Trinity’s video guy who spent a morning interviewing us and our students and shooting video about the process. As far as I know that video is not out yet, but it was great practice for our two seconds of fame when Jon and I were interviewed by the local NBC station.
NBC’s investigative reporter Len Besthoff spent a few hours with us and we ended up with 10 seconds of fame a few hours later. Instant fame ensued: even our neighbors are suddenly recognizing us in the street!

In October Jon and I attended a concrete symposium in Trois-Rivières and just in time, on the up North, we received an e-mail that our paper on thermomagnetic pyrrhotite testing was finally accepted for publication in Cement and Concrete Research. By now it’s actually published and you can download a copy from here (until December 1st ). The meeting in Quebec was amazing. Since my French is pathetic we all got headphones and enjoyed the amazing skills of two simultaneous translators. Jon and I felt like at the United Nations.

At the United Nations :-)

By now we’re working on a new manuscript to be presented at the annual meeting of the American Geophysical Union (AGU) in Washington DC, and are eagerly awaiting our new rock crusher to help with all the concrete cores that are flooding the lab.

I’d say it has been an interesting summer.


ENVS Summer Research – Shane, Bobbie, and Joe

This summer, Shane McLaughlin (’19), Anna Maria “Bobbie” Imwalle (’20), and Joe Ruggiero (‘19) worked with me (Dr. Amber Pitt) to investigate the impacts of human activity on wildlife populations and freshwater ecosystems in urban Connecticut and rural Pennsylvania.

Getting the dirt on urban ponds and streams

Bobbie collecting urban pond sediment


Ponds and streams can serve as critical habitats for wildlife in urban settings. However, they also can become ecological traps for wildlife if they are contaminated with toxins that decrease reproduction and survival. Wildlife can accumulate toxins through direct contact with the substances in the environment, as well as by consuming contaminated food sources such as plants and animal prey species. Shane and Bobbie took to the ponds, while Joe took to the streams, in parks in the Greater Hartford Area to explore contaminant levels in sediments and plants found within these ecosystems. Shane and Bobbie also assessed amphibian, reptile, and bird diversity in these ecosystems. They found that some ponds and stream segments were more impaired than others with contaminants such as mercury. Results were somewhat surprising though in that some of the most impacted ponds were located in the more beautiful, highly vegetated settings. It’s likely that those results were due to the application of lawn and gardening chemicals that contain mercury. These results suggest that use of such chemicals may pose a threat to wildlife in these habitats, as well as to people who recreate in and consume fish from these ecosystems.

Helping the hellbender

Shane, Bobbie, and I headed to Pennsylvania to continue research on hellbenders. Hellbenders are giant salamanders that live in streams and rivers in the eastern United States, from southern New York to northern Georgia, and west to Missouri. Their populations are declining throughout much of their range, and the Pitt lab has been researching the drivers of this decline so that we can better understand how to reverse these trends and conserve this species. Donning masks and snorkels, we took to the streams to survey the hellbender population.

Bobbie and Shane getting ready to snorkel.

While many hellbender populations show no signs of recruitment, our efforts uncovered a larval hellbender, indicating a healthy, reproducing population.

A larval hellbender we found.

Going to bat for bats

As an extra treat while in Pennsylvania, Shane, Bobbie, and I joined one of my former graduate students, Jamie Shinskie, for a night of bat surveys. Bat populations have declined precipitously due to white-nose syndrome, and an important step in conserving bats is to monitor their populations to understand how the populations are changing over time.

Shane setting up a mist net to catch bats.

One of the bats captured in the mist net.

Shane and Bobbie recording morphometric data for the bat researchers.

Oh Canada

With data and presentations in hand, Shane, Joe, and I headed to Canada to share the results of our research! Shane and Joe presented the urban pond and stream research and I presented hellbender research at the North American Congress for Conservation Biology in Toronto, ON. This professional scientific conference was attended by more than 800 people who specialize in conservation science, policy, and communication.

Shane and Joe explaining the urban pond and stream study.

Our group also took some time for bird watching while in Toronto…sort of. With the Rogers Centre just a few blocks from the conference venue, the group decided to take in a Blue Jays game. The Blue Jays may have lost that night, but our lab team shared a winning experience.

Shane, Amber, and Joe at a Toronto Blue Jays game.

ENVS Summer Research – Nicole

The goal of Nicole’s research is to see if it is possible to reconstruct a history of past fires through charcoal analysis. Charcoal is used as an indicator to reconstruct past fire dynamics and, when coupled with other paleoecological proxies, can be used to enhance paleoecological reconstructions.

Soil profile HNC 15-G

The soil samples come from a series of locations within the Hitchcock Nature Center in Pottawattamie County, Iowa (41.4209°N, -95.8659°W). The samples were collected at 5 cm intervals up to a depth of 2.3 meters at each location. A small amount of each sample was mixed with 0.10 M KOH solution in a centrifuge tube. The tubes were then placed in an ultrasonic bath to break up soil fragments and was then passed through a 180 mm screen. The coarse fraction was rinsed with deionized H2O to remove any fine particles and the remaining sample transferred to a petri dish. Charcoal was identified at 20x magnification under a microscope and separated from the rest of the sediment sample for analysis. Charcoal particles were photographed, and their surface area was determined through image analysis performed in ImageJ.

This is what macroscopic charcoal looks like.

Charcoal concentrations are reported in mm2/g. The soil profile was dated using four radiocarbon ages obtained from charcoal fragments and snail shells. All soil ages were in chronological order and the oldest soil samples were approximately 780 years old. Prior to approximately 1870 average charcoal concentrations are low and relatively consistent in most samples.

An image of Nicole’s soil profile, several magnetic parameters, and Nicole’s charcoal counts (in brown). The spike in charcoal occurred approximately at the end of the 19th century.

At a depth of 30 cm below surface, there was a spike in the amount of charcoal up that is higher than most of the rest of the sample. This spike dates to approximately 140 years ago and its timing correlates with the onset of large-scale settlement of Pottawattamie County by European settlers. Settlers likely burned the original forest and grasslands to create viable land for farming. After this initial spike, the level of charcoal decreases but continues to stay elevated. This could be a result of less frequent burning to keep the unwanted biomass at bay.

prescribed fire at Hitchcock Nature Center

Two ENVS Talks at the Science Symposium

At this week’s science symposium we enjoyed two talks from our ENVS majors. Joe Ruggiero presented work on his research on pyrrhotite in Connecticut metamorphic rocks and how it affects the stability of concrete. Pyrrhotite acts as a source of sulfate which can lead to internal sulfate attack (ISA) in concrete foundations. ISA due to pyrrhotite-containing aggregate is the cause of premature concrete failure which affects thousands of homes in northeastern Connecticut.Sarah Messenger, an ENVS / BIOL double major, presented her work on permeable reactive barriers and their role in controlling nitrate inputs into estuaries. Sarah’s thesis started out as a semester-long research project with MBL at Woods Hole. She continued her study on the efficacy of these barriers and is currently working with Dr. Lisa Foster identifying the bacterial communities involved in nitrate reduction.

Both, Joe and Sarah, did an outstanding job. Congratulations!

Summer Research – Krista Ehlert

Hi! I’m Dr. Krista Ehlert and I’m the Thomas McKenna Meredith ’48 Postdoctoral Fellow in Environmental Science (phew!). My students and I have a plethora of diverse, but connected, research projects. The Ehlert lab at Trinity is focused on ecologically based management of invasive plants, with a special focus on Berberis thunbergii, Japanese barberry. Specifically, we’re looking at the intersection between Japanese barberry, Ixodes scapularis (the black-legged tick), climate change, and Lyme disease. Forests invaded with Japanese barberry have twice as many ticks as those that aren’t; this is associated with the fact that Japanese barberry creates the ideal, humid environment that ticks need to avoid desiccation. Here’s a closer look at what we’ve already completed and are currently investigating in the Ehlert lab:

Recent ENVS alum Adam assessed different survey methods of Japanese barberry in Simsbury, CT. Adam specifically used transects and GIS to quantify the extent of invasion at our study site. Along each 50 m transect, Adam utilized a quadrat to count Japanese barberry density and cover. With GIS, Adam downloaded NDVI (normalized difference vegetation index) satellite data to map Japanese barberry locations, as you can see in the map below. The NDVI values closely align with the dense shrubbery that we associated with Japanese barberry from Adam’s transects.

Adam trapped in the barberry with his quadrat.

Map displaying 2016 NDVI vegetation coverage and their equivalent values within the study site.

Blair, another recent ENVS alumna,  investigated the invasivore movement, specifically as it related to Japanese barberry. The invasivore movement is a means of eradicating invasive species through human consumption. In the past, the fruit of Japanese barberry has been used to make…jam! Blair went to work by first conducting a strong literature review of the invasivore movement and how it became popularized. Next, she spent time in the kitchen! Blair was able to successfully produce jam from Japanese barberry, providing an alternative means of controlling this insidious invader.

Blair holding the jam she produced from Japanese barberry fruit, alongside the poster she presented at the student research colloquium in Spring 2017.

Soon to be ENVS alumna Corinne and I are investigating the role of horses as potential vectors of invasive plant seeds. Corinne and I are interested in this research question because we each have a horse! Horses are able to transport invasive seeds not only through their digestive tract, with seeds ending up in their feces (eek!), but their manes, tails, and fur can also easily transport seeds. We’re focusing on the latter for Corinne’s research. Corinne started her research by conducting a survey of Intercollege Horse Show Association (IHSA) horseback riders, to learn about their attitudes toward and knowledge of invasive plants. We will be expanding upon the survey by conducting experiments with our own horses and others to investigate how far seeds can travel when attached to their fur.

Corinne presenting the results of her survey at the student research colloquium in Spring 2017.

Another soon to be alumna, Bailey from the Biology department, spent the summer along with Blair helping me with the Japanese barberry research (see previous blog post!). Bailey will be expanding on this research for her senior thesis in the Biology department, and will be co-advised by Dr. Amber Pitt and I. Specifically, Bailey will be focusing on the effect of microhabitat on black-legged tick abundance on the white-footed mouse, Peromyscus leucopus. White-footed mice are reservoirs of Borrelia burgdorferi, the bacteria that causes Lyme disease. Ticks feed on mice for one of their blood meals, become infected, and move on to their next blood meal – often a human, thereby transmitting Lyme disease. Bailey will accomplish this research by using live-catch traps in the field, and counting tick load on each captured mouse; after counting is complete, the mouse will be released back into the wild. Overall, we hope that Bailey’s project sheds light on tick load on white-footed mice in a Japanese barberry infested forest.

Biology student Bailey in the field with a Japanese barberry shrub that has been uprooted.

That’s a wrap on what the Ehlert lab has accomplished and is currently doing! I’m actively looking for one or two research students this fall to help on the Japanese barberry project, so if you’re interested, send me an email at: krista.ehlert@trincoll.edu or stop by McCook 123! Or stop by if you’re interested in other invasive plant research!

Summer Research – What the Ehlert lab has been up to

Bailey (left) and Blair (right) having fun pulling Japanese barberry.

This summer, Dr. Krista Ehlert and her research students have been investigating the role of in situ climate change on different management strategies for Japanese barberry (Berberis thunbergii), and how that in turn, affects the black-legged tick (Ixodes scapularis), which serves as a reservoir for Lyme disease. The two summer research students in the Ehlert lab are ENVS alumna Blair Frantz ’17 and Biology student Bailey D’Antonio ’18. A lot of the work we’ve done so far has been setting up open top climate chambers (OTCs) that utilize the greenhouse effect to increase the temperature inside the chamber by 1-3°C – what models are estimating with climate change. We also employed different management strategies for Japanese barberry, such as pulling the plant and applying herbicide and compared those to an untreated control. The data that we’ve collected includes vegetation surveys, temperature recordings, and ticks! This data will continue to be collected into the fall, and once we have a few hundred-ish (or more) ticks, we’ll be testing them for Lyme disease. Overall, we’ve had a great summer and are excited to uncover more about the indirect effect Japanese barberry has on Lyme disease incidence in Connecticut. If you want to learn more about what the Ehlert lab is up to follow us on Instagram @ thescientificlunaticks.

Japanese barberry encircled by an open-top climate chamber (OTC).

Catch of the day!

Krista Ehlert Gives Talk on Research on Japanese Barberry and Lyme Disease

E-M1_7_smThis Friday Krista Ehlert, our current postdoctoral fellow, gave a presentation on her research project on the links between Japanese Barberry (an invasive plant), Lyme disease and climate change. Krista’s talk was well attended, possibly thanks to at least one difficult mid-term exam and the promise of generous extra credit for students enrolled in the introductory and earth systems courses.

In her talk, Krista pointed out that there is a strong correlation between the abundance of Japanese barberry and black-legged ticks – the main (only ?) vector for Lyme disease in Connecticut. Krista’s research will build on these established relationships between invasive plants, ticks and Lyme disease and study how Japanese barberry will be affected by a warmer climate. In collaboration with the Simsbury Land Trust, Krista will simulate the effects of a warmer climate on Japanese barberry and tick populations using open top chambers. Krista also gave us an outline about her ongoing research projects, which include among others a study on seed dispersal by horses.

If that sounds interesting, contact Krista, and maybe you’ll find yourself out in Simbsury collecting ticks or counting barberry plants.

Krista had a mostly attentive audience ...

Krista had a mostly attentive audience …

... and even Christoph managed too stay awake through the entire talk.

… and even Christoph managed too stay awake through the entire talk.

Our students enjoyed the talk, and Krista may be the only speaker so far ...

Our students enjoyed the talk, and Krista may be the only speaker so far …

… who had fans rushing up to her afterwards to have their pictures taken.

… who had fans rushing up to her afterwards to have their pictures taken.

Waist-deep in mud and other recent happenings


Earthquake !

Earthquake !

To say that not much has happened since my last post is an understatement. To say that the transition from a sabbatical back to teaching was no big deal might be even a bigger one. I could get used to showing up in the lab each morning, doing a few measurements and thinking a few deep thoughts in my office… Needless to say, the last few weeks were a bit busy: we hired two new faculty members (more on that in an upcoming post), I am teaching three courses, and my research students keep me busy too.

Nevertheless, I was in for a (very nerdy) treat this Saturday. For years I have been walking past our seismograph, checked the screen and saw nothing, or noticed an earthquake that had happened some place on earth.  “Nice“, I usually thought, “that was a big one, better check out where it happened…“. This Saturday, however, while packing the car for a quick sampling trip to Hammonasset State Park I saw the waves arrive while I stared at the screen. It was cool to think that for a few minutes the biggest vibrations in the building came from a place a few thousand miles away. I stared for a while, returned to packing the car (T.J. was supposed to show up in half an hour, so I didn’t want to be late), and snapped a picture of the screen a bit later. The earthquake, it turned out occurred at 11:26 UTC in the Caribbean, and you can read all about it here.

Looks dry to me ... how tricky can it be to get a core from here?

Looks dry to me … how tricky can it be to get a core from here?

The sampling trip was exciting as well. T.J. and I headed down to Long Island Sound to core a salt marsh in Hammonasset State park. We’ve been there before in the winter of 2014 when everything was frozen. This time it was different: the marsh was one soupy mess. On our first walk out to the coring site, T.J. went in to his knees. On our second trip out I  went in to my chest. That’s when I decided that the camera would stay on dry land. After a few more trial and errors we had it pretty much figured out and stayed dry – until we cut corners – and in we went again. Nevertheless, we got eight meters of hideously smelly core with no bottom in sight. So, we might find ourselves some football players, hope for a colder winter next year, and return in January for a third try. In the meantime, T.J. will analyze what we have, and the cores will stink up the fridge, lending that particular aroma to McCookout stuff.

Psychedelic cores ...

Psychedelic core … HAM 16A – drive 1 – the first of eight beautifully smelly salt marsh cores.