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Honoring the achievements of emeritus faculty Dr. Edward C. Monahan

Edward C. Monahan Symposium

Thursday, July 25th, 2019

Monahan Symposium
Colleagues, family, and friends celebrated Dr. Monahan.

In the old-world tradition of a Festschrift, i.e., a celebration and book honoring the life and achievements of outstanding academics, the Department of Marine Sciences celebrated Dr. Edward C. Monahan in a full day symposium. Colleagues from Ed’s many years at UConn and Connecticut Sea Grant recounted entertaining anecdotes and his many accolades. Outside of academia, friends shared stories about his intense love for rowing crew and his involvement in local politics. One of the shining moments of the day included a photo montage of Ed’s facial hair throughout the years. Two beautiful quilts, crafted by Ed’s wife Elizabeth, were displayed throughout the festivities. One quilt captured rolling waves, the pattern being different shapes for different words for white caps. The other quilt displayed every institutional emblem in chronological order at which Dr. Monahan worked.

Dr. Monahan studied at Cornell University as an undergraduate in Engineering Physics, and continued onto his Ph.D. in Oceanography at the Massachusetts Institute of Technology, where he focused on the correlation between sea spray, whitecap coverage, and wind speed. His career brought him across the world to Ireland, where he completed another Doctorate of Science at the National University of Ireland. For two decades, he led the Connecticut Sea Grant program at UConn as its Director and initiated international marine sciences exchanges. In his retirement, Ed has not slowed down his scholarly productivity. He continues to publish scientific journal articles, remains active in the department, and stays abreast of all things oceanography by attending weekly seminars and brown bag presentations.

Dr. Penny Vlahos, chair of the symposium organizing committee, commented, “Ed and I have collaborated since I started as junior faculty. I thought it was appropriate to honor him and recognize his achievements and contributions. His work is still being cited today, especially by climate scientists in IPCC [Intergovernmental Panel on Climate Change] reports.”

Some wonderful words come from Peg Van Patten, retired communications director for Connecticut Sea Grant, “Ed Monahan was my supervisor as Director of Connecticut Sea Grant for two decades, but he was really more than that.  Ed became my mentor, and friend, and sometimes my co-author. I learned so much from his experience that I was delighted when Professor Vlahos asked me to help organize a symposium in his honor.  The day was a perfect tribute to Ed’s remarkable career and many accomplishments.”

Throughout the symposium, selected guests gave scientific talks on topics related to Ed’s research interests: sea spray, white caps, and air-sea interaction. Other speakers included grant recipients from Connecticut Sea Grant, collaborators, rowing partners, and students. In his retirement, Ed helped organize Coastsweek Regatta, a local rowing competition in Mystic, with 2019 marking the 28th consecutive year. At the closing of the day, attendees, family and friends enjoyed celebratory beverages and birthday cake appropriately decorated with a large wave. Allison Staniec, a current Ph.D. student who works directly with Ed, summarized the day quite well: “The Monahan Symposium (Twixt Wind and Waves) was an enjoyable celebration of Ed’s past and ongoing career with plenty of time for ground breaking science and entertaining anecdotes. And cake!”

The Festschrift book, “Recent Advances in the Study of Oceanic Whitecaps,” edited by P. Vlahos and E. C. Monahan (Honorary Editor) will be published by Springer Nature shortly.

Summer ’19 Synopsis

Although the academic year is over by mid-May, the Department of Marine Sciences does not take a summer vacation. Outreach, research trips, summer interns, and more activities keep Marine Sciences bustling during the summertime. Included here are just a few of the programs from summer 2019.

 

Marine Sciences and Mystic Aquarium REU program

This year marked the last class in the inaugural cycle of our new NSF funded Research Experience for Undergraduate (REU) program with the Mystic Aquarium. Our REU students came from all corners of the country: California, Florida, Iowa, and Maine. Eight REU students were paired with Marine Sciences Faculty or Mystic Aquarium researchers on projects that spanned all levels of the marine food web. The program provides students with housing, a stipend for working full-time in a lab and for food, and all transportation. The students just focus on conducting science! This year featured new collaborative projects between DMS and the Aquarium, such as the first ever documentation of ciliate diversity and population dynamics of Beluga Whale blowhole spit. The Marine Sciences Graduate Student Organization also integrated itself into the REU program by providing invaluable peer support for oral and poster presentation experience. After a laudatory site visit by the NSF program manager, we were encouraged to apply for another four years of funding and to increase the number of students to 10. Our fingers are crossed we can continue this exciting and rewarding program.

 

STEM Success and Student Support Services

STEM Success, the undergraduate retention program for incoming Science Technology Engineering Mathematics (STEM) students, returned this summer! Fourteen in-coming undergraduate students enrolled, who are either first-generation college students, from low-income households, part of underrepresented populations within UConn, or in need of some extra academic support.

For four weeks, students participated in eight workshops, twice-a-week, that were designed to promote discussion amongst peers and with graduate students on STEM subjects and life at Avery Point. Activities ranged from performing titrations, carrying out plankton tows, introducing programming, and learning how to use a microscope. This enabled the incoming undergraduates to become familiar with basic scientific concepts and laboratory etiquette, readying them for their science classes this Fall. The primary goal was to add another layer of support for these students by fostering connections with their peers and their future teaching assistants.

For the second year in a row, the STEM Success program occurred alongside the intensive five-week Student Support Services summer program directed by Aaron Collins. Twice as many marine sciences graduate students got involved this year to lead the workshops. STEM Success has been designed and coordinated by Dr. Emma Cross the previous two years and she is now handing over the reins to Dr. Lisa Nigro. Our graduate students were super enthusiastic and all the incoming first-years enjoyed and found the program useful!

 

Pre-college at Avery Point

The Department of Marine Sciences participated in UConn’s pre-college summer program for the second time. The program, titled “marine biology and oceanography” enrolled 17 students from Connecticut, Massachusetts, New York and Saudi Arabia (by way of New Hampshire). The students stayed in Storrs and were transported to Avery Point during the week. Students’ favorite activities included taking water quality measurements around Pine Island off the R/V Lowell Weicker, exploring invertebrate ecology from settling plates, going on a behind the scenes tour of the Aquarium, and dissecting dogfish. Instructors were Claudia Koerting and John Hamilton. The program ran the last full week of July.

 

UConn Summer Undergraduate Research Fund (SURF) Awards

Each summer, UConn awards close to 50 undergraduates with financial support to explore a research project of their own device through the Summer Undergraduate Research Fund (SURF). Over the last few years, Marine Sciences undergraduate students have consistently received recognition. This year, seniors Mackenzie Blanusa and Annalee Mears were fully funded for summer research. Mackenzie combined atmospheric science and chemical analysis in her project entitled, “The Effect of Storm Type and Source Region on the Chemical Composition of Precipitation along the Long Island Sound Coastline.” Dr. Kelly Lombardo and Dr. Zofia Baumann mentored and guided her research. Annalee worked with Dr. Catherine Matassa on a project about predator-prey interactions called, “Stoichiometry of Fear: Do Predators Affect the Balance of Carbon and Nitrogen in their Prey?” Previous SURF recipients include Clare Schlink (2018), Sarah McCart (2017) and Jessica Hinckley (2019). We are proud of our undergraduates for their great contributions!

Departmental Achievements

Since the last newsletter edition, many members of the Department of Marine Sciences were awarded grants, published articles, and received fellowships and awards. Congratulations to everyone on their remarkable achievements! All are presented in alphabetical order by last name.

Publications:

Hannes Baumann Contrasting genomic shifts underlie parallel phenotypic evolution in response to fishing.

 

Zofia Baumann Chapter 5: Ocean Transport of Radioactive Materials. Section 10: “Radioactive caesium in marine migratory animals.”

 

Ann Bucklin and Heidi Yeh Time-series metabarcoding analysis of zooplankton diversity of the NW Atlantic continental shelf.

 

Heidi Dierssen Evaluating the seasonal and decadal performance of red band difference algorithms for chlorophyll in an optically complex estuary with winter and summer blooms.

 

Water column optical properties of Pacific coral reefs across geomorphic zones and in comparison to offshore waters.

 

Pushing the limits of seagrass remote sensing in the turbid waters of Elkhorn Slough, California.

 

Modeling atmosphere-ocean radiative transfer: a PACE Mission perspective.

 

Atmospheric correction of satellite ocean-color imagery during the PACE Era

 

Retrieving aerosol characteristics from the PACE Mission, Part 1: ocean color instrument.

 

Retrieving aerosol characteristics from the PACE Mission, Part 2: multi-angle and polarimetry.

 

Felipe Porto Long Non-Coding RNA Expression Levels Modulate Cell-Type-Specific Splicing Patterns by Altering Their Interaction Landscape with RNA-Binding Proteins.

 

Matthew Sasaki and Hans Dam Integrating patterns of thermal tolerance and phenotypic plasticity with population genetics to improve understanding of vulnerability to warming in a widespread copepod.

 

Emily Seelen and Rob Mason The interaction of mercury and methylmercury with chalcogenide nanoparticles.

 

Samantha Siedlecki Observational needs supporting marine ecosystems modeling and forecasting. (accepted)

 

Cloud and radiative effects of a Northeast Pacific marine heat wave. (accepted)

 

An enhanced ocean acidification observing network: from people to technology to data synthesis and information exchange.

 

Better regional ocean observing through cross-national cooperation: a case study from the Northeast Pacific.

 

Samantha Siedlecki and Penny Vlahos Carbon cycling in the North American coastal ocean: a synthesis.

 

Pieter Visscher Carbonate precipitation in freshwater cyanobacterial biofilms forming microbial tufa.

 

J. Evan Ward Selective ingestion and egestion of plastic particles by the blue mussel (Mytilus edulis) and eastern oyster (Crassostrea virginica): implications for using bivalves as bioindicators of microplastic pollution.

 

 Fellowships:

Mackenzie Blanusa and Annalee Mears UConn Summer Undergraduate Research Fund (SURF)

 

Elisabeth (Lissa) Giacalone Dominion Energy student internship, working in environmental compliance at Millstone Power Station, Waterford, CT

 

Vena Haynes Doctoral Dissertation Fellowship from the UConn Graduate School

 

Gunnar Hansen Doctoral Student Travel Fellowship from the UConn Graduate School

 

Abigail Kwiat NSF Research Experience for Undergraduates through University of Chicago Marine Biological Laboratory at the Plum Island Ecosystem Long Term Ecological Research site

 

Kayla Mladinich Doctoral Student Travel Fellowship from the UConn Graduate School

 

Grants:

Julie Granger and Samantha Siedlecki Investigation of mechanisms leading to seasonal hypoxia in the Southern Benguela Upwelling System.

 

Rob Mason Collaborative Research: Constraining the role of chemical transformations in the cycling of mercury in the Arctic Ocean air-sea interface.

 

Samantha Siedlecki Assessment of the observing network to identify processes relevant to the predictability of the coastal ocean of the Northeast on centennial time scales, NOAA OAP.

 

Pieter Visscher 2019-2020 Synchrotron Soleil/CNRS-CEA: Spatial distribution of metals in microbialites as biosignatures: Linking the modern to the fossil record and search for life on Mars. Visscher (PI), Bouton (Co-PI); Fifteen shifts of beamtime in the Nanoscopium, Synchrotron Soleil, Paris, France.

 

 Awards:

Ann Bucklin Outstanding Achievement Award at ICES Annual Science Conference.

Ann Bucklin receiving award

 

Where are they now? Alumni Spotlight – Michelle Fogarty

michelle fogarty portrait
pictured, Dr. Michelle Fogarty

Despite the 2-hour time difference, Michelle Fogarty answers my Skype call with enthusiasm at 8:30am MDT. Michelle is a recent Marine Sciences alumna, who is now based in Boulder, Colorado working at the National Renewable Energy Laboratory (NREL). While at UConn, she studied air-sea interactions with Dr. Melanie Fewings. She graduated with her PhD in 2018, and her dissertation is available online for those interested in learning more. We spoke about her job search process, her current position, and advice she has for current graduate students. Interviewer: Molly James

 

Molly: What is your current position?

Michelle: I am a Postdoctoral Researcher in Marine Energy Resource Characterization at the National Renewable Energy Laboratory, Flatirons Campus, in Boulder, CO. I’ve been there for 8 months, since February 2019. NREL is a DOE-owned, contractor operated national lab, and we work with industry and academic partners to accelerate the commercialization of renewable energy technologies and diversify the US’s energy portfolio.

 

Q: How did you hear about it?

Michelle: I remember seeing the posting online somewhere — probably on LinkedIn, the Coastal List listserv or the MPOWIR jobs board. But, I didn’t apply based on the posting because there was no contact information for the principal investigator (PI), only instructions for submitting an application through the online portal. Without being able to research more about the group I’d be working with, I didn’t pursue it further. Later when I attended the Mid-Atlantic Bight Physical Oceanography and Meteorology (MABPOM) conference, I spoke with an acquaintance who knew about the NREL position and offered to send an introductory email to the PI. After a phone call with the PI, I decided to apply.

 

Q: What was the hiring process like?

Michelle: Over the course of three months, October to December 2018, I submitted my cover letter and CV, had a phone interview with Human Resources, and visited Boulder for an in-person interview. During the in-person visit, I gave a 15-minute presentation and fielded questions from a group of about 10 people, which was followed by a 1-hour Q&A session with a smaller interview committee that covered a larger range of topics and allowed me to ask questions of them as well.  A few weeks later, I was offered the job. I drove from CT to CO and reported for work at the beginning of February [2019]. I think it’s worth pointing out that from a hiring standpoint, there’s a difference between being brought on as a researcher or as a postdoc. As a postdoc, the main focus is on building your professional capacity, and NREL is committed to providing opportunities and mentorship along the way.

 

Q: What are you researching?

Michelle: As a member of the Marine Hydrokinetic Energy (MHK) group within the Water Power team, I am working on tidal energy resource characterization. My first project is to calculate characteristic flow and turbulence statistics from data collected at the Western Passage site near Eastport, Maine and write a journal article describing the results. That data was collected before I began at NREL. I’m also working on preparations for another tidal energy site resource characterization field campaign in Cook Inlet, Alaska. The results of both projects will document relevant flow conditions at potential tidal energy sites, to be used to validate regional circulation models, and will help device simulation tools estimate realistic loads on tidal turbines. More recently, I’ve started to coordinate with outside partners to get two new wave buoys deployed in 2020 to increase our wave resource characterization efforts. I am motivated by knowing that the results of my research will be used to help solve real-world problems.

 

Q: What is your work life like and how does it differ from your experience during grad school?

Michelle: There is little obvious hierarchy at NREL on a day to day basis like there was in grad school (undergraduate students/graduate students/postdocs/staff/faculty, etc.). While I still do a lot of work independently, we work in teams. On a weekly basis I participate in more collaborative efforts than I typically did during grad school. I work with people at all stages in their careers, and the tasks I’m given are based on my skills, my willingness to participate, and my availability.

I work a 40-hour week and complete a time sheet that accounts for each hour of work and which project the work was associated with, so that’s quite a bit different than the grad school structure. It feels more like a consulting job, where you are required to bill out your hours to a specific project. I have a cubical, and most of my time is spent working independently at my desk, with various project-based and MHK or Water Power group meetings throughout the week. I will continue to attend conferences like Ocean Sciences to keep in touch with the network of people I developed during grad school, and will get to know a new community of people at marine energy related conferences, too.

 

Q: What advice do you have for current graduate students?

Michelle: Talk to as many people as possible, you never know which connection will turn out to be useful. Keep notes of those interactions. Start doing this as early in your graduate school career as possible so 1) you get comfortable with it and 2) you develop relationships out of genuine interest and aren’t making the initial attempt to network at the moment you need something. Talk with people who have jobs like the one you think you want and to people who have jobs you’re “sure” you have no interest in. Do this through informal conversations at conferences, at events that have nothing to do with work, and invite people you’ve met in person or found online to participate in informational interviews with you on the phone or in person. I highly recommend sending hand-written thank you notes after those informational interviews, too. I have always been impressed at how willing people are to give their time and sending a thank you card is a small way to show how much you appreciate the kindness.

Plastic pollution needs a new bioindicator

Stories about the impact of plastic pollution on marine organisms have been flooding the news with upsetting images of sea turtles with plastic straws stuck in their nostrils, and whales dying with tons of plastic in their stomachs. Besides large animals, plastic is potentially harming the creatures that wind up on our dinner plate, like bivalve shellfish. Bivalves filter ocean water to eat plankton, which suggests they are ingesting small plastic particles, called microplastics, every time they feed.

Researchers in UConn’s Department of Marine Sciences recently conducted a study exploring how common, commercial bivalves interact with microplastics when filter feeding. Ph.D. students Kayla Mladinich and Tyler Griffin, working with Professor J. Evan Ward, collected eastern oysters and blue mussels from Long Island Sound for laboratory experiments, in which they were exposed to plastic spheres and/or plastic threads of different sizes.

bivalves
Eastern oyster (left) and blue mussel (right).

For spheres, their findings show that both mussels and oysters always reject the largest-sized plastic spheres, but ingest and expel smaller ones. For threads, however, there was not a clear pattern between rejection or ingestion, and length.

Mladinich explains, “Bivalves are selective feeders. While they can capture particles of various sizes and shapes on their gills, they will not eat everything they are exposed to. They can ingest or reject certain particles based on the size, shape, and surface properties.”

Dr. Ward and his lab group have shown that bivalves are not passively ingesting all types of plastics, rather the size and shape of the plastic matter a lot. This finding has implications for using bivalves as bioindicators for plastic pollution in the ocean.

Bioindicators are species used to represent the concentrations of pollutants and contaminants in an environment. In the ocean, bivalves are already utilized to monitor and determine levels of persistent organic pollutants (POPs), which can cause a variety of diseases in humans.

According to the World Health Organization, the most commonly encountered POPs are pesticides, industrial chemicals, and unintentional by-products of many industrial processes, such as DDT, PCB and PCDD, respectively. Recently, some scientists suggest also using bivalves as bioindicators for plastics pollution in the ocean.

feces and plastics figure
Difference between oysters and mussels feeding on microplastics (courtesy of publication).

According to the Ward lab, the criteria for a good microplastics bioindicator species include (1) being ubiquitous and relatively easy to collect; (2) interacting significantly with the surrounding environment through particle-feeding processes; and (3) ingesting, without bias, the majority of plastic particles in the environment.

Therefore, says Mladinich, “We should reconsider using bivalves as bioindicators for microplastics pollution, because as this study shows they capture, ingest, and reject plastic particles differentially. Bivalves are not consuming particles passively; they have selection mechanisms and bias.”

“If you went out and opened up a mussel or oyster and counted all the types and sizes of microplastic particles, you would not be getting an accurate representation of the microplastic load in that area,” added Griffin. “We should investigate other filter feeders that better satisfy our criteria.”

Unfortunately, mussels and oysters do not follow these criteria because they selectively consume some microplastics over others. Additional studies suggest that most plastics do not accumulate in shellfish tissues because they are readily eliminated on short timescales.  “Our study supports the idea that many plastic particles encountered by bivalves are either rejected prior to ingestion or rapidly egested in feces, so the instantaneous microplastic body burden of the animals is low,” explains Dr. Ward. Nonetheless, long-term effects of a low microplastic body burden in bivalves are not yet known.

More experiments are being conducted by Dr. Ward and his students that explore the impacts of microplastics on the gut microbiome of mussels, the selection of microscopic fibers depending on size and polymer type, and other topics.

Ward Lab 2019
The Ward Lab, summer 2019.

Researchers from Marine Sciences at the 14th ICMGP in Krakow, Poland

The bi-annual week-long conference, International Conference on Mercury as a Global Pollutant (ICMGP) was held in Krakow in Poland in September. During this conference academic researchers, consultants, policy makers and companies that specialize in mercury analytical instrumentation showcased recent developments in their specific areas. Graduate and undergraduate students and faculty from the Department of Marine Sciences (listed below) presented their findings on mercury in atmosphere and marine environment and enlarged their professional networks. The Distinguished Professor (emeritus) William Fitzgerald, who has pioneered the field of Marine Mercury in the Department of Marine Sciences here at UConn, was also among the attendees (seen on one of the photographs with his former student and current UConn faculty, Prof. Robert Mason).

Dr. Robert Mason, Professor

Dr. Zofia Baumann, Assistant Research Professor

Mackenzie Blanusa, Undergraduate

Gunnar Hansen, Ph.D student

Yipeng He, Ph.D student

Wesley Huffman, Ph.D student

Patricia Myer, Ph.D student

Zooplankton vulnerability to Warming: Go with the Flow, But It Is Complicated

Work from Professor Hans Dam’s laboratory (https://marinesciences.uconn.edu/faculty/dam/) led by Ph.D. student, Matthew Sasaki (https://marinesciences.uconn.edu/students/sasaki/) shows that zooplankton vulnerability to warming depends on a complex interplay of population dispersion, local adaptation, and phenotypic plasticity. Thus predicting the fate of the oceanic biota to climate change is a multifaceted issue that requires careful integration of oceanography, ecology, and evolution.

The work (https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.14811) is published in the prestigious journal Global Change Biology, and is also highlighted in a lay-audience article (https://today.uconn.edu/2019/09/ocean-dweller-ability-respond-warming-waters-location/?utm_source=listserv&utm_medium=email&utm_campaign=daily&utm_content=uconn-today) in the online Magazine, UConn Today.

DMS graduate student participates in Oceanhackweek 2019

For the first week of the semester, PhD student Molly James participated in the second annual Oceanhackweek, hosted by the eScience Institute at University of Washington in Seattle, WA. Oceanhackweek brings together a diverse group of people at all career stages and at every level of coding experience. The organizers state it best: “In contrast to conventional academic conferences or workshops, hackweeks are intensive and interactive, facilitated by three core components: tutorials on state-of-the-art methodologies, peer-learning, and on-site project work in a collaborative environment.”

Molly learned about and completed tutorials on data science tools in the oceanographic community. The topics of the tutorials included Github, cloud computing, Jupyter notebooks, python visualization tools, machine learning, and other open source resources. She also organized a “hack” project that addressed the issue of co-locating data from disparate data servers, in order to either validate or supplement a data set with another. Her group decided to approach this task by looking at over 30 ERDDAP servers hosted by different organizations. The group utilized Jupyter notebooks and python packages to create a user-friendly search tool that queries these multiple servers simultaneously. Despite having less than 5 days to work together, the team produced a beta-version of the search tool by the end of Oceanhackweek. The documentation and code development is available on their team Github code repository.

Other interested scientists of all levels should keep an eye out for the application to Oceanhackweek 2020! It is a great opportunity to build community and confidence in computing skills.

Oceanhackweek Oceanhackweek

Ann Bucklin presented with ICES Outstanding Achievement Award

Molecular biologist Ann Bucklin presented with Outstanding Achievement Award during the opening ceremony of ICES Annual Science Conference in Gothenburg, Sweden.  

​​​​​​​​Ann Bucklin has made significant contributions to ICES over a long career marked by a continued high level of commitment to excellence in science, research, and training. For more than 20 years, Ann has been a member of ICES community and has had an ongoing impact in the field of marine science over this time.

Her contributions were recognized at the opening of ICES Annual Science Conference 2019 in Gothenburg, Sweden.

Read the complete article here: https://www.ices.dk/news-and-events/news-archive/news/Pages/An-outstanding-role-model-Ann-Bucklin-presented-with-Outstanding-Achievement-Award.aspx

Fishing changes silverside genes

Over recent decades, many commercially harvested fish have grown slower and matured earlier, which can translate into lower yields. Scientists have long suspected that rapid evolutionary change in fish caused by intense harvest pressure is the culprit.

Now, for the first time, researchers have unraveled genome-wide changes that prompted by fisheries – changes that previously had been invisible, according to a study published in Science by a team of researchers including Hannes Baumann, UConn assistant professor of Marine Sciences, who collaborated with researchers at Cornell University, the University of Oregon, the National Marine Fisheries Service, and Stanford University.

In unprecedented detail, the study shows sweeping genetic changes and how quickly those changes occur in fish populations extensively harvested by humans, says Baumann.

“Most people think of evolution as a very slow process that unfolds over millennial time scales, but evolution can, in fact, happen very quickly,” said lead author Nina Overgaard Therkildsen, Cornell assistant professor of conservation genomics in the Department of Natural Resources.

In heavily exploited fish stocks, fishing almost always targets the largest individuals. “Slower-growing fish will be smaller and escape the nets better, thereby having a higher chance of passing their genes on to the next generations. This way, fishing can cause rapid evolutionary change in growth rates and other traits,” said Therkildsen. “We see many indications of this effect in wild fish stocks, but no one has known what the underlying genetic changes were.”

Therkildsen and her colleagues took advantage of an influential experiment published back in 2002. Six populations of Atlantic silversides, a fish that grows no bigger than 6 inches in length, had been subjected to intense harvesting in the lab. In two populations, the largest individuals were removed; in another two populations, the smallest individuals were removed; and in the final two populations, the fishing was random with respect to size.

After only four generations, these different harvest regimes had led to evolution of an almost two-fold difference in adult size between the groups. Therkildsen and her team sequenced the full genome of almost 900 of these fish to examine the DNA-level changes responsible for these striking shifts.

The team identified hundreds of different genes across the genome that changed consistently between populations selected for fast and slow growth. They also observed large linked-blocks of genes that changed in concert, dramatically shifting the frequencies of hundreds of genes all at the same time.

Surprisingly, these large shifts only happened in some of the populations, according to the new paper. This means that there were multiple genomic solutions for the fish in this experiment to get either larger or smaller.

“Some of these changes are easier to reverse than others, so to predict the impacts of fisheries-induced evolution, it is not enough to track growth rates alone, we need to monitor changes at the genomic level,” said Therkildsen.

When the experiment was originally conducted nearly two decades ago by co-authors David Conover, professor of biology at the University of Oregon, and Stephan Munch of the National Marine Fisheries Service, the tools to study the genomic basis of the rapid fisheries-induced evolution they observed were not available. Fortunately, Conover and Munch had the foresight to store the samples in a freezer, making it possible to now return – armed with modern DNA sequencing tools – and reveal the underlying genomic shifts.

Research like this can assess human impacts, and improve humanity’s understanding of “the speed, consequences and reversibility of complex adaptations as we continue to sculpt the evolutionary trajectories of the species around us,” Therkildsen said.

“What’s most fascinating about this is that life can find different genetic ways to achieve the same result. In this study, two experimental populations evolved smaller body size in response to the selective removal of the largest fish, which is what most trawl fisheries do. However, only by looking at the genetic level we demonstrated that these two experimental populations evolved via two completely different genetic paths,” says Baumann.

The good news for the Atlantic silversides is that the fisheries selection was able to tap into the large reservoir of genetic variation that exists across the natural range of this species from Florida into Canada, said Therkildsen: “That genetic bank fueled rapid adaptation in the face of strong fishing pressure. Similar responses may occur in response to climate-induced shifts in other species with large genetic variability.”

“Scientists have coined the term Anthropocene in recognition of the all-pervasive human alteration of the earth’s climate, oceans, and land. No matter how ‘pristine’ a piece of nature may look to us at first glance, examine it thoroughly enough and you will find a trace of human in it. Take a cup of water from the middle of Pacific Ocean and a handful of sand from a ‘pristine’ beach – and you will find little plastic particles under the microscope,” says Baumann. “The parallel to this study is that the all-pervasive human meddling in our planet’s affairs now undeniably reached the genetic make-up of its organisms. Today’s fishes may superficially look the same as always, but their genes are not. They bear witness to human alteration.”

In addition to Baumann, Therkildsen, Conover, and Munch, co-authors included former Cornell postdoctoral researcher Aryn P. Wilder, now a researcher at San Diego Zoo Institute for Conservation Research; and Stephen R. Palumbi, Stanford University.

This work was funded by the National Science Foundation.