Name: Molly Newton ’11
Major: Geology and Environmental Studies
Hometown: Easthampton, Mass.
Summer activity: Researching beach erosion at Popham Beach with geologist Mike Retelle

Molly Newton ’11, cradling lengths of rebar, gazed around Popham Beach, uncertain where to plant the steel.

Seeking guidance for the crucial first step of her research project, she looked to her two professors. “And they looked at me and asked where we were going to start,” Newton recalls. “They weren’t kidding.”

One professor was Bates geologist Mike Retelle. The other was her own father, a geology professor at Smith College and a good friend of Retelle’s. And as for lengths of rebar, they were GPS survey markers for an ongoing Bates project to measure sand erosion at Popham and other beaches near the Bates–Morse Mountain Conservation Area.

“My Bates education has blasted apart the limitations I placed on myself.”

Newton calls geology “the family trade,” yet she arrived at Bates determined to avoid the field. “To anyone who would listen, I proclaimed that I was in no way smart enough for science, let alone intellectually capable of executing a study of my own design.”

But then she took a geology course her sophomore year, then another. And on that summer 2010 morning at Popham Beach, when Newton made her own decisions about her project, she felt that she had emerged as a Bates student scholar.

“That Mike and my father did not dispute my choices gave me the confidence to jump into a full summer of research feet first, and not be afraid to make my own decisions.”

Now, as a senior, she’s diving into her geology thesis. The capstone project will use data accumulated from her Bates-funded summer work that, in turn, builds on Retelle’s research with prior students.

“My Bates education has blasted apart the limitations I placed on myself,” she says.

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The meandering Morse River ends its assault on Popham Beach

By Kirsten Weir

The Bates Outing Club clambakes at Popham Beach State Park are one reason this sandy stretch of Maine coastline is a touchstone of the Bates experience.

Longtime BOC adviser Judy Marden ’66 recalls the clambake ritual from her Bates days: “The night before, we’d go out and gather driftwood, then camp overnight. Early the next morning we’d dig pits and start the fires. Then we cooked the lobsters in trash cans with clams and corn.”

But this spring, the state asked the BOCers to relocate their clambake, which they did, to Reid State Park a few miles to the east. The reason: There’s not much public beach left at Popham.

Indeed, while an idealized and immutable Popham looms large in the alumni consciousness, the beach itself has rapidly eroded during the 2000s. These days, only a few feet remain at high tide.

If Popham Beach is this story’s protagonist, then the antagonist is the Morse River, which exits the coast just west of Popham Beach. In recent years, the river has migrated eastward, cutting away at Popham’s beach, particularly the western part of the beach, though the center beach, which connects to Fox Island, has also been eroded significantly.

“We’ve been watching this river shift its course gradually for a long time,” says Bates geology professor Mike Retelle. By 2005, he says, “we started noticing massive changes” to the Morse River and Popham Beach.

Two factors pushed the river toward the beach. “A double whammy,” Retelle says.

One was the relentless growth of a sand spit just offshore from the Morse River outlet. The spit was created by a wave and sand mechanism called longshore sand transport, in which sand-carrying waves hit the shore at an angle and gradually deposit their sediments. Retelle and Dana Oster ’09 dubbed the Morse River spit “I-95” for its great length and width, and it became an “insurmountable barrier” that blocked the Morse from flowing directly into the ocean.

The sand spit deflected the river toward the beach, and the erosion just got worse and worse. “It was like a firehose,” Retelle says. As kayakers and canoeists know, when a river curves, the fastest and most powerful flow is the outside of the curve. As the Morse curved into Popham Beach, the strongest part of the current was eating away at the beach.

“You want to see natural processes play out,” Retelle says.

River outlets are always “the most dynamic places” along the coast, says Retelle. Even so, the stunning changes at Popham had observers “in a panic” by this past winter, Retelle says. Erosion had carved deeply into the dunes and toppled hundreds of shoreline pine trees. The ocean was within feet of the parking lot, and it threatened the park’s new bathhouses. State geologists say it’s the beach’s greatest retreat in a century.

In its inexorable eastward march, the river had even cut through the sand bar, known as a tombolo, making it nearly impossible for visitors to walk from Popham to Fox Island.

This past February, some local residents urged that a channel be cut through the sand spit to allow the river to return to a north-south orientation. But others said that the river, and nature, should take its course.

“From an environmental perspective, you want to see natural processes play out,” Retelle says. “Otherwise you won’t know what would have happened.”

The Bates–Morse Mountain Conservation Area is just across the Morse River from Popham Beach, and director Laura Sewall also opposed taking action.

“The mission of the conservation area emphasizes protecting ecological integrity and educational opportunities. That’s primary,” says Sewall.

She subscribes to a philosophy promoted by naturalist Aldo Leopold, she explains: “If you want to understand a natural system, you can’t study one that has already been in any way altered.”

While public attention peaked over the winter, scientists like Retelle and state geologist Stephen Dickson had already seen evidence that the river was about to change course.

In April 2009, as Retelle and his students were doing measurements on that aforementioned I-95 sand spit, they saw a dry channel right across the spit, about 2 meters wide — evidence that the river had momentarily breached the spit during a recent storm and its associated high tide.

According to Dickson, the channel was the first sign of “a new, and more direct, course to the sea across the…spit.” In fact, winter storms had begun shaving the sand spit little by little over the last two years, Retelle says. He and Dickson agreed that a few more fierce winter storms would do the trick.

On Feb. 25 and 26, 2010, a major northeaster proved them right, as gale winds and high tides helped the Morse River barrel through the mound of sand to create a new north-south flow away from Popham Beach.

“I never know what I’m going to see when I go down to Popham.”

With summer’s arrival, calmer wave action should allow sand to be re-deposited along Popham, explains Retelle, so the beach should begin to grow again. In fact, Retelle and his geology thesis student, Molly Newton ’11 of Easthampton, Mass., are now working with the state to monitor the recovery of Popham Beach.

It’s an intriguing project, he says. “I never know what I’m going to see when I go down to Popham.”

Kirsten Weir is a science writer based in southern Maine.

At the Bates-Morse Mountain Conservation Area in September, Emily Chandler ’09 of North Yarmouth, Maine (above), with Dana Oster ’09 of Mercer Island, Wash., and Professor of Geology Mike Retelle, surveys Seawall Beach to monitor the transport and erosion of beach sediment. Here, Chandler calculates the distance from her benchmark location to the water’s edge. Researchers have noticed measurable sand transport along parts of Seawall Beach, and extensive erosion at adjacent Popham Beach.

Photograph by Phyllis Graber Jensen

The Harward Center for Community Partnerships has awarded three Publicly Engaged Academic Project grants to Bates faculty members, the first of two rounds of awards for 2007-08. These “PEAP” grants are designed to offer faculty and staff significant support for publicly engaged teaching, research, cultural and other community projects. In the current round, three faculty-led projects received grants totaling $11,223.

“The diversity of the projects funded by these grants underscores the creativity with which Bates faculty link public engagement to their teaching, research and artistic work,” noted David Scobey, director of the Harward Center. “These grants fund work in dance, cultural studies and environmental research. The range of publicly engaged academic work represented in these grants is impressive.”

The three PEAP recipients and their proposals are:

• Myron Beasley, visiting assistant professor of American cultural studies and African American studies, for “What Androscoggin County Eats,” a Short Term course that will investigate local foodways across different cultural communities and stage a “performative meal” at the Bates Mill in partnership with Museum L-A;

• Carol Dilley, assistant professor of dance, for “FAB: Franco-American Bates Dance Showcase,” a regional dance showcase co-produced by the Bates dance program and the Franco-American Heritage Center, including Bates student dancers and leading Maine choreographers and presenters;

• Mike Retelle, professor of geology, for “An Environmental Archive of Seawall Beach,” which will pair Bates students and Midcoast conservation advocates to monitor and research the historical effects of climate and tidal changes on beach, dune and salt marsh ecosystems at the beach near Bates-Morse Mountain Conservation Area.

“It’s exciting that these projects not only connect faculty with community partners, but also involve Bates students in important public work,” Scobey said. “I’m proud that the PEAP grants can support such innovative parts of the Bates education.”

The Harward Center has offered the second round of PEAP grants for this year. New proposals are due on April 18. For more information, please visit the Harward Center website, or contact David Scobey.

In Kongsfjorden on the west side of Svalbard, Will Ambrose (facing) and Kelton McMahon ’05 haul a dredge to collect Serripes groenlandicus and other clam species for McMahon’s thesis in 2004. Photograph by Glenn Lopez, SUNY–Stony Brook.

Professor Will Ambrose, a bearded biologist specializing in Arctic sea-floor ecology, is a pioneer in the science of deciphering the past — including past climates — by studying the annual hard-tissue accretions of organisms such as mollusks.

As an expert in sclerochronology, Ambrose has discovered a link between Arctic clam growth and regular shifts in the region’s climate. In short, Arctic clams grow more rapidly during regimes of warm and wet weather and less during cold and dry regimes. This sensitivity to climate change, says Ambrose, makes the humble bivalve a “sentinel of climate change.”

While Ambrose is collaborating on no fewer than five clamshell research projects at the moment, the scientific paper that detailed the initial findings of a correlation between climate change and Arctic clamshells appeared in Global Change Biology in September 2006.

Seen here is the cross section of a small portion of aSerripes groenlandicus shell, near the umbo, or hinge. The lines indicate annual growth: dark lines for slow winter growth; light areas indicate fast summer growth. For an image showing the complete shell, click the image above. Will Ambrose has discovered a correlation between growth and climate shifts. This image is a composite of 18 images produced by the College’s new Imaging and Computing Center using a Nikon SMZ 1500 stereo microscope. Collected in 1926, the shell’s actual length is 2.5 inches.

The paper emerged from work done three years earlier, when Ambrose dispatched divers to the bottom of a high Arctic fjord in the Svalbard archipelago, a popular Arctic research site about halfway between the Norwegian mainland and the North Pole. From the ocean bottom, the divers returned with four Greenland cockles (Serripes groenlandicus).

After encasing the shells in epoxy and slicing them apart, Ambrose and a team of scientists, including Kelton McMahon ’05, analyzed the growth bands. First, the team found that growth bands were indeed deposited annually. Then the team was able to correlate annual differences in shell growth with a measurement of Arctic weather oscillations known as the Arctic Climate Regime Index.

“What makes the work exciting,” says Ambrose, interviewed in his cluttered office on Carnegie’s third floor, “is that this is the first time in the Arctic that we’ve been able to track a large-scale climatic oscillation and see that large-scale regional event reflected in animals living on the bottom.”

While scientists have for decades analyzed growth lines in shells (Ambrose and others call them “trees of the sea”) in order to reconstruct past environments, the intensity around climate-change research has “really made the field of sclerochronology take off,” he says.

In this hot field, Ambrose’s research is distinctive for its location, on the Arctic continental shelf. “A lot of the work has been done at lower latitudes, mostly because it’s harder to get clams in the Arctic and there are simply fewer people available to help,” he says. “That’s why we’re ahead of the ball.”

If it’s true that Arctic clams grow faster in warmer weather (and grow faster when there’s less of a seasonal ice pack, another signal that Ambrose saw hints of), a simplistic response might be, “Great — fatter clams for walruses to munch on.” But, explains Ambrose, fat clams won’t offset the problems walruses are having due to less pack ice to rest on. And less ice will also affect tiny creatures inside the ice that are the first link in a food chain for polar cod, seabirds, and seals. And so on, throughout the Arctic food web.

These Serripes groenlandicus clams were collected in Storfjord at a site last visited by 19th-century Russian explorers. Photograph by Greg Henkes '08.

In the end, changes in water temperature and salinity (due to runoff from melting glaciers) and increased sea levels, leading to erosion and turbidity, will all take their toll on the Arctic ecology. “Ecosystems operate at the interface of physics, chemistry, and biology, with both complementary and contradictory interactions,” Ambrose writes in a forthcoming article predicting that “regional, and perhaps global, biodiversity will suffer.”

Until recently, Ambrose researched other organisms of the benthic community, such as bloodworms along Maine’s coast. A simple matter of funding helped bring bivalves into focus, as a Bates grant (from the Philip J. Otis Endowment) and an external one (from the Howard Hughes Medical Institute) helped purchase a pricey Isomet low-speed saw for preparing shell cross-sections. “Very expensive,” Ambrose says.

In researching the biological response of Arctic bivalves to climate change, Ambrose has depended on the interests and expertise of colleagues and students at Bates and abroad.

Geology professor Beverly Johnson, for example, has been invaluable in co-advising biology students so they can learn to use the College’s stable isotope ratio mass spectrometer, a tool to help identify the age and origins of molecules in various materials. Johnson herself has used the instrument to look at amino acids in dinosaur eggs, and it can likewise be used to tease out the chemical components of clamshells.

“I work with Will to understand how modern systems work,” says Johnson, “and then go back to old shells, using the geochemistry of shells from 125,000 years ago to reconstruct the environment.”

Ambrose also depends on Matt Duvall, who directs Bates’ new Imaging Center, to create elegant microscopic images of his clamshell sections that Ambrose calls “just incredible.”

Geology professor Mike Retelle, another Svalbard regular who specializes in reconstructing climates from lake sediments, has collaborated with Ambrose on researching climate-change information from fossilized Ice Age clams.

Beyond the sciences, Ambrose, Johnson, and Retelle belong to an informal North Atlantic Study Group on campus that also includes archeologists Gerald Bigelow and Bruce Bourque, historian Michael Jones, and political scientist Áslaug Ásgeirsdóttir. What started informal — an interdisciplinary coffee klatsch — has given rise to “North Atlantic Studies,” a thematic grouping of Bates courses, known as a concentration, under the College’s new general education requirements. “We represent an area of study, rather than just a bunch of us sitting around having coffee,” Ambrose says.

“It’s a truly special group,” Retelle adds. “The richness of discussion is such that the boundaries between disciplines disappear. The walls of the box dissolve. Will is a big part of that. As a model for an undergraduate institution, Will has really raised the bar.”

Ambrose himself is quick to point out that “students here are the ones driving the bus in terms of getting the work done.” As he speaks, Greg Henkes ’08 of Chapel Hill, N.C., is downstairs in the environmental geochemistry lab cutting shells and extracting organic material. Henkes’ senior thesis involves a study of 130 years of climate change in the Barents Sea and Svalbard using a historic Russian collection of Serripes groenlandicus. He will present his findings to an American Geophysical Union conference in San Francisco.

Greg Henkes ’08, one of Will Ambrose’s thesis students, took this photograph at 3 a.m. on June 3, 2007, as the research shipLance heads through sea ice in Storfjord in the Svalbard archipelago, about halfway between the North Pole and Norway.

“It’s pretty incredible to be able to do this at Bates,” says Henkes. “It’s the way science is going,” says Ambrose of the collaborative nature of scientific enquiry, noting his international partnerships with colleagues at the Norwegian Polar Institute and the research firm Akvaplan-niva. “People aren’t doing their own little thing anymore.”

“That’s the way science should be done,” emphasizes Kelton McMahon, co-author of the Serripes groenlandicus paper. “In certain circles, it is. But a lot of people come from departments that don’t share data because they feel funding is in direct competition. Bates takes a very progressive approach to interdisciplinary research.”

McMahon is now working on his Ph.D. in a program co-sponsored by MIT and the Woods Hole Oceanographic Institution. His contribution to the clamshell research has been to use two gizmos — a New Wave Research UP213 laser ablation system coupled to a Thermo Finnigan Element 2 single collector field inductively coupled plasma mass spectrometer — to measure the chemical components of shell samples. Ambrose et al. used changes in the ratio of strontium to calcium to establish that the external lines of the Greenland cockleshells were, in fact, annual growth lines. “If it wasn’t for Kelton getting us access to those machines,” says Ambrose, “the paper wouldn’t have been anywhere near as good.”

As he sits in his Carnegie office discussing his work — Ambrose also hopes to extend his sclerochronology research to coral in part because “they live much longer than clams” — he is eagerly awaiting a new shipment of Svalbard shells that he hopes will solve a quirk in his findings. Until recent years, Ambrose found that annual clam growth was high in years when the extent of Arctic ice pack, as measured each March, was low. But over the last several years, “growth didn’t track ice cover the way it did before. Something happened, but we’re not sure what,” he says. “Are the last four years unnatural? That’s why I want those new clams. It’s another four years of data that will help establish some baselines.” And baselines will help provide more answers, which will probably just beget more questions. It’s the wayscientific inquiry works. “People like simple answers,” Ambrose says. “Nature doesn’t.”

By Edgar Allen Beem

Freelance writer Edgar Allen Beem wrote about the College’s sustainability initiatives in the Fall 2007 issue of Bates Magazine.

Michael J. Retelle, a professor of geology at Bates, is one of 13 scientists across the nation to share nearly $1,500,000 in National Science Foundation funding for Arctic research related to global climate change.

The NSF funds, awarded for a four-year period beginning March 1, support an ongoing project to create a 2,000-year climatic history of the North American Arctic. The researchers are analyzing layers of sediment deposited annually upon Arctic lake beds for clues to climatic conditions during the past two millennia, clues such as sediment thickness and chemical composition.

The NSF grant totals $1,476,442, of which Retelle’s share is $50,190. That money will defray costs of analyzing six lake-floor core samples that Retelle collected in 2003 from lakes on Devon, Cornwallis and Bathurst islands, near Greenland in Canada’s Nunavut Territory. Retelle and three students (including Dan Frost, a senior from Farmington, Maine) will process the samples this summer.

Titled “Collaborative Research: A Synthesis of the Last 2,000 Years of Climatic Variability from Arctic Lakes,” the NSF-funded project is intended to provide a context for better understanding of current climatic trends. “It’s important to try to put the recent climatic warming in a longer-term perspective, and to try to tease out whether what we’re looking at is part of the range of natural variability or, indeed, if it’s a result of human alteration of the atmosphere,” Retelle explains.

“The further we can go back and see how the natural system works, the better we can put this recent warming into context and try to understand what’s controlling it.”

Analyzing core samples from 30 lakes across a region of the North American Arctic from Alaska to the northwest Atlantic, the researchers will integrate their results of their work and, they hope, be able to announce findings by 2007. The project extends a 400-year Arctic climatic history project whose results were widely publicized in 1997.

Retelle explains that, as records (or “proxies,” in scientific parlance) of the weather from year to year, layers of lake sediment can be likened to tree-growth rings. Thicker layers can signify warmer summers that promoted plant growth in the lake or rainstorms that washed soil into the lake. Also informative are levels of carbon, nitrogen and substances like biogenic silica, a hard remnant of algae.

Retelle and his assistants will analyze the samples through a variety of means, including an X-ray fluorescence spectroscopy system at the University of Laval, Quebec.

Climate is a central theme of Retelle’s work, and in nearly 30 years’ worth of visits to the Arctic, he has seen climate-related changes that he calls “actually frightening.” He points to Ellesmere Island, 480 miles from the North Pole, where floating coastal ice shelves have receded dramatically and lake ice that once persisted year-round is now seasonal. “There are radical changes,” he says.

The grant is the latest in a series of NSF awards that Retelle has received for Arctic lake-bed study and for bringing students into this research. (More than 20 of Retelle’s students have conducted research in the Canadian Arctic for senior thesis projects.) He has done geological research in the Arctic since 1976, when he worked as a field geologist and engineer on the Trans-Alaska Pipeline.

Retelle, of Monmouth, has worked at Bates since 1987. His teaching and research are focused on geological events of the past 1,600,000 years — called the Quaternary Period — and specifically ancient environmental records from glacial, lake and marine sediments in Maine as well as the Canadian arctic.

Here in Maine, with Thomas Weddle of the Maine Geological Survey, Retelle has published findings from an ongoing survey on the impacts of the retreat from Maine of Ice Age glaciers, including changes in sea level. He also works with students in assessing seasonal effects of weather at the Bates-Morse Mountain Conservation Area, Phippsburg.

Retelle is a senior researcher for the Svalbard Research Experience for Undergraduates, a summer project funded by the NSF and hosted by Mount Holyoke College, that brings six students to the Norwegian Arctic to research the effects of climate change upon high-latitude glaciers, melt-water streams and sedimentation in lakes and fjords.

He graduated with a bachelor’s degree in earth sciences from Salem (Mass.) State College, and earned graduate degrees in geology at the University of Massachusetts.