Month: March 2023

Heat tolerance changes across environments and populations

March 27th 2023 - By Ewaldo Leitao.

Climate change is a threat to species persistence. Increasing temperatures affect species differently depending on their habitats, such as land or the ocean. However, species often consist of different populations (groups of individuals that reproduce together) that experience different temperature conditions. And if populations live in these areas long enough, they can genetically adapt to their local conditions. What does that mean? If the same species has a population in an area where it is constantly warm, like the tropics, and another population that lives in colder regions, like Connecticut, then we’d expect the tropical population to handle high temperatures better compared to the population living in colder regions. This kind of diversity within species affects how we think about the vulnerability of the species as a whole. To add another layer, if variation differs for terrestrial vs. oceanic species, we might be missing important information about where climate change will have the strongest effects on the planet.

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Matt Sasaki looking at a water sample with a handheld microscope at Lake Okeechobee, FL.

That is what Dr. Matt Sasaki and collaborators investigated in a paper recently published in Nature Climate Change. Their main goal was to assess the heat tolerance (the highest survivable temperature) of populations in many different species, from different realms – terrestrial, freshwater, marine and intertidal. They assessed the vulnerability of species by surveying in the literature from the whole world that measured individual heat tolerance. They compiled and then conducted a meta-analysis of these published data, thereby assessing how the heat tolerance is related to the thermal environment these populations live in.

“This paper came out of the ‘Evolution in Changing Seas’ Research Coordination Network (RCN). Back in 2019 they brought some of us together at Shoal’s Marine Lab for a synthesis workshop and essentially told us to think about questions at the intersection of evolutionary biology and marine science”, said Matthew Sasaki, about the seed of the idea.

"I really enjoyed the collaborative aspect of this project, even though I’ve met most of the co-authors in person only once (or not at all!)"

By measuring how heat tolerance changes between populations of the same species, they found that marine and intertidal species show a decrease of heat tolerance between populations as the environment gets colder, but that was not observed in terrestrial and freshwater populations. This was an interesting result, because since the ocean is largely connected, they expected that there would be a smaller differentiation in the ocean compared to land, where geographical barriers can create physical separations, allowing difference in heat tolerance to build up among populations within a species.

Behavior may play a role in the observed patterns. In the terrestrial realm, many organisms can moderate body temperature by seeking shade and forested areas to find refuges from the heat. Even plants can exploit micro-climates. This decreases the amount of evolutionary pressure on terrestrial organisms, when compared to other realms.

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Data surveyed to analyze global patterns of heat tolerance. The histogram on the left side shows the higher proportion of studies in the northern hemisphere (Modified after Sasaki et al. 2022).

This study highlights the importance of accounting for evolutionary processes in the context of climate change and species persistence and extinction risk. Larger differentiation of heat tolerance within species may suggest a potential for evolutionary rescue. That is, populations with genes that allow them to be “warm adapted” may rescue populations that are more susceptible to increasing warming.

We asked what was the coolest part about the execution and findings of the project. “This wasn’t a project someone could do alone, and it was really cool to be part of such a big collaborative effort. The findings themselves were also really exciting for us. We expected there to be pretty clear differences between marine and terrestrial taxa, but we were surprised to see that local adaptation seems to be stronger in marine species and not terrestrial species. This goes against some of the traditional paradigms (that marine species’ are more often homogenized by larval dispersal, for example), and hints at a cool role of behavioral thermoregulation in shaping patterns in evolutionary adaptation.”

“This was definitely a pandemic pet project. I won’t say the pandemic helped us make progress though. This ended up being something we worked on a little bit each week for a couple years. Maybe that helped us put together a more robust product (slow and steady wins the race?). I really enjoyed the collaborative aspect of this project, even though I’ve met most of the co-authors in person only once (or not at all!). Having to do everything virtually definitely changed the nature of the collaboration (more written exchanges, less whiteboard brainstorming) but I think we made it work. We’ve just started working together on a couple new projects that build from this initial work, so it must not have been too terrible.”, said Matt.


Sampling freshwater mussel gut microbiomes in the Great Lakes

In June 2022, Hannah Collins and Tyler Griffin from the Ward Environmental Physiology Lab went to Buffalo, NY, to perform research on the gut microbiomes of freshwater quagga mussels (Dreissena bugensis). The three-day trip involved collecting these invasive mussels from Lake Erie with the help of Brian Haas at the Buffalo State Great Lakes Center field station. The goal of the project, funded by an NSF Emerging Frontiers in Research and Innovation grant, was to sample mussel gut microbes before and after defecation with the goal of distinguishing between microbes that live inside the mussels and other microbes that were simply passing through. This work serves as preliminary research for the larger goal of investigating the feasibility of using freshwater mussels to remove microplastics from freshwater systems and co-concentration them with plastic-degrading bacteria.

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PhD student Hannah Collins taking samples of mussel guts for microbiome analyses (Photo: Tyler Griffin)

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Invasive Quagga mussels (Dreissena bugensis)

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View over the Niagara River in June 2022

Jamie Vaudrey selected for Faculty Environmental Leadership Award

Jamie-Vaudrey

16 March 2023. DMS is proud to announce that Prof. Jamie Vaudrey has been selected for the 2023 Faculty Environmental Leadership Award (ELA). This award recognizes individuals who have worked alone or as part of organizations to support sustainability efforts at UConn and beyond.

Since 2005, the Office of Sustainability, within the Institute of the Environment has honored faculty members, students and staff members who have made a positive impact on the environment through their leadership in the classroom, lab, or in the communities which UConn serves

Dr. Vaudrey was nominated, because of her exemplary role as an environmental leader over the past years. She sets the standard for outreach in the Department of Marine Sciences. Communicating science is the fiber that runs through all of her research and teaching. She does this across a broad array of stakeholders often with competing interests. Her outreach extends well beyond advisory to active partnerships with citizen scientists, regulators, municipalities, and industry. It has helped to shape the stewardship trajectories of waters and watersheds regionally, and seagrass ecosystems worldwide.

Her leadership roles in professional societies and on advisory councils have pushed for more integration of scientific results into decision making and broadened participation of underrepresented groups in marine science. Dr. Vaudrey’s key role in gathering the momentum for establishing the Connecticut National Estuarine Research Reserve was her crowning achievement of years of meticulous, patient teamwork, where she led countless meetings to bring experts, policymakers and public stakeholders to the table and eventually, through dialogue and her own unique way of gentle persuasion, make the CT NERR a reality in 2022.

In addition, Dr. Vaudrey has led numerous, hands-on team efforts in recent years to work on sea grass restoration and living shorelines initiatives, where she has been inspiring students and volunteers by practically working alongside them in the field. Dr. Vaudrey’s compassion for nature and the future of Long Island Sound emanates from her everyday work, which is a key motivating force for every member of her team.

Dr. Vaudrey also works with Save the Sound and helped develop an Environmental Report Card for Long Island Sound which has engaged senators and other state and federal agencies to seek additional funding for research on environmental impacts on local waters. Jamie is also the Coordinator for the Niantic River Watershed Committee, and she is an outspoken advocate for environmental issues in our local marine waters. Her impact on understanding of environmental and sustainability impacts in CT’s local waters reaches far beyond the classroom, but she is devoted to educating the next generation of scientists and managers on these important issues.

Prof. Catherine Matassa wins UConn-AAUP Teaching excellence award

Matassa-Excellence-Award

23 March 2023. DMS is proud to share that Prof. Catherine Matassa has been selected for a 2023 UConn-AAUP Excellence Award in the Early Career Teaching category. This is well deserved, because since joining our department, Catherine has distinguished herself as one of the most cherished, effective and innovative educators for undergraduate and graduate students of our Department and CLAS. Her enthusiasm for Marine Biology and her innovative approach to teaching Quantitative Methods and Experimental Design are a true enrichment to students and faculty alike.

Here are some excerpts of what colleagues and students had to say about Catherine's teaching:

"In addition to providing the foundational basis of marine ecosystems, she facilitates transformative learning experiences with hands-on laboratory and field activities where students apply their knowledge and conduct independent research. Courses where students conduct independent research require much larger investment of time and energy from the instructor." Prof. Heidi Dierssen

"Almost from the time I arrived at UConn in 1995, I heard colleagues in Marine Sciences discussing the need for an Experimental Design/Statistics course for our students. Being located at Avery Point has always limited our participation in Storrs-based classes, so we tried, and failed, several times to develop a course of our own. When Catherine arrived, the problem was solved. Her class, MARN 4210Q Experimental Design in Marine Ecology, covers the basics of hypothesis testing and gives students a good working knowledge of R, the state-of-the-art computing environment for scientific statistics." Prof. George McManus

"Catherine created the experimental design and analysis course to address the demand for a course that covered statistics, coding and design. The course provided us with real data to run analyses on in R and posed questions, which we addressed with experimental design. The homework was dynamic and helped me hone my abilities coding in R and interpreting statistical results. I took a statistics class during my undergraduate studies but gained a much better understanding of analyses with Catherine's hands-on approach." Kayla Mladinich, PhD student

"I took Dr. Matassa’s Marine Biology course in the Fall of 2022. I personally was impressed with how innovative and diverse the content that she included in the class was. The laboratory experiments perfectly complemented the lecture period and helped me relate the information on the slides to real life situations. The ability to write and explore our own independent projects as well provided creative freedom that many other class labs seem to be lacking, and she did well to encourage critical thinking and exemplify how our experiments relate to real marine problems. Her inclusion of science communication in the curriculum was also a refreshing innovation to the lecture period, and something I had not experienced before in a STEM class." Greg Aniolek, undergraduate student

"Dr. Matassa coordinated an engaging field trip to Avery Point that was an exciting opportunity for students to expand their knowledge outside of the classroom. This opportunity included a tour of the Long Island Sound on a Project Oceanography research boat. While the tour was guided by two Project Oceanography educators, Dr. Matassa took every chance to communicate additional information that related to our classroom studies and energetically answered the questions that were raised. Dr. Matassa had something interesting and relevant to say about every species that we collected on the boat." Lukas Liebowitz, Senior Biology Major 2023